^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * AMD Memory Encryption Support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2019 SUSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Author: Joerg Roedel <jroedel@suse.de>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #define pr_fmt(fmt) "SEV-ES: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/sched/debug.h> /* For show_regs() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/percpu-defs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/mem_encrypt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/printk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/mm_types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/set_memory.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/memblock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <asm/cpu_entry_area.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <asm/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <asm/sev-es.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <asm/insn-eval.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <asm/fpu/internal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <asm/processor.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <asm/realmode.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <asm/traps.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <asm/svm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <asm/smp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <asm/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #define DR7_RESET_VALUE 0x400
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) /* For early boot hypervisor communication in SEV-ES enabled guests */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * Needs to be in the .data section because we need it NULL before bss is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * cleared
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static struct ghcb __initdata *boot_ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /* #VC handler runtime per-CPU data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct sev_es_runtime_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) struct ghcb ghcb_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * Reserve one page per CPU as backup storage for the unencrypted GHCB.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * It is needed when an NMI happens while the #VC handler uses the real
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * GHCB, and the NMI handler itself is causing another #VC exception. In
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) * that case the GHCB content of the first handler needs to be backed up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * and restored.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct ghcb backup_ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * Mark the per-cpu GHCBs as in-use to detect nested #VC exceptions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * There is no need for it to be atomic, because nothing is written to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * the GHCB between the read and the write of ghcb_active. So it is safe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * to use it when a nested #VC exception happens before the write.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * This is necessary for example in the #VC->NMI->#VC case when the NMI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * happens while the first #VC handler uses the GHCB. When the NMI code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * raises a second #VC handler it might overwrite the contents of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * GHCB written by the first handler. To avoid this the content of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * GHCB is saved and restored when the GHCB is detected to be in use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * already.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) bool ghcb_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) bool backup_ghcb_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * Cached DR7 value - write it on DR7 writes and return it on reads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) * That value will never make it to the real hardware DR7 as debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * is currently unsupported in SEV-ES guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) unsigned long dr7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) struct ghcb_state {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) /* Needed in vc_early_forward_exception */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) void do_early_exception(struct pt_regs *regs, int trapnr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) static __always_inline bool on_vc_stack(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) unsigned long sp = regs->sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /* User-mode RSP is not trusted */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (user_mode(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* SYSCALL gap still has user-mode RSP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) if (ip_within_syscall_gap(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) return ((sp >= __this_cpu_ist_bottom_va(VC)) && (sp < __this_cpu_ist_top_va(VC)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * This function handles the case when an NMI is raised in the #VC exception
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) * handler entry code. In this case, the IST entry for #VC must be adjusted, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * that any subsequent #VC exception will not overwrite the stack contents of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * interrupted #VC handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) * The IST entry is adjusted unconditionally so that it can be also be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * unconditionally adjusted back in sev_es_ist_exit(). Otherwise a nested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * sev_es_ist_exit() call may adjust back the IST entry too early.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) void noinstr __sev_es_ist_enter(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) unsigned long old_ist, new_ist;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /* Read old IST entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) old_ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /* Make room on the IST stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (on_vc_stack(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) new_ist = ALIGN_DOWN(regs->sp, 8) - sizeof(old_ist);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) new_ist = old_ist - sizeof(old_ist);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) /* Store old IST entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) *(unsigned long *)new_ist = old_ist;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) /* Set new IST entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], new_ist);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) void noinstr __sev_es_ist_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) unsigned long ist;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) /* Read IST entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) if (WARN_ON(ist == __this_cpu_ist_top_va(VC)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /* Read back old IST entry and write it to the TSS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], *(unsigned long *)ist);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) * Nothing shall interrupt this code path while holding the per-CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * GHCB. The backup GHCB is only for NMIs interrupting this path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * Callers must disable local interrupts around it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) static noinstr struct ghcb *__sev_get_ghcb(struct ghcb_state *state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) struct sev_es_runtime_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) WARN_ON(!irqs_disabled());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) data = this_cpu_read(runtime_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) ghcb = &data->ghcb_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) if (unlikely(data->ghcb_active)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) /* GHCB is already in use - save its contents */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) if (unlikely(data->backup_ghcb_active)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * Backup-GHCB is also already in use. There is no way
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * to continue here so just kill the machine. To make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * panic() work, mark GHCBs inactive so that messages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * can be printed out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) data->ghcb_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) data->backup_ghcb_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) instrumentation_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) panic("Unable to handle #VC exception! GHCB and Backup GHCB are already in use");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) instrumentation_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) /* Mark backup_ghcb active before writing to it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) data->backup_ghcb_active = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) state->ghcb = &data->backup_ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) /* Backup GHCB content */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) *state->ghcb = *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) state->ghcb = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) data->ghcb_active = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) return ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) /* Needed in vc_early_forward_exception */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) void do_early_exception(struct pt_regs *regs, int trapnr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) static inline u64 sev_es_rd_ghcb_msr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) return __rdmsr(MSR_AMD64_SEV_ES_GHCB);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) static __always_inline void sev_es_wr_ghcb_msr(u64 val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) u32 low, high;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) low = (u32)(val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) high = (u32)(val >> 32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) native_wrmsr(MSR_AMD64_SEV_ES_GHCB, low, high);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) unsigned char *buffer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) return copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) char buffer[MAX_INSN_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) int res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (user_mode(ctxt->regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) res = insn_fetch_from_user_inatomic(ctxt->regs, buffer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) if (!res) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) ctxt->fi.vector = X86_TRAP_PF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) ctxt->fi.cr2 = ctxt->regs->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) if (!insn_decode(&ctxt->insn, ctxt->regs, buffer, res))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) res = vc_fetch_insn_kernel(ctxt, buffer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) if (res) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) ctxt->fi.vector = X86_TRAP_PF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) ctxt->fi.error_code = X86_PF_INSTR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) ctxt->fi.cr2 = ctxt->regs->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) insn_get_length(&ctxt->insn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) ret = ctxt->insn.immediate.got ? ES_OK : ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) char *dst, char *buf, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) unsigned long error_code = X86_PF_PROT | X86_PF_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * This function uses __put_user() independent of whether kernel or user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * memory is accessed. This works fine because __put_user() does no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) * sanity checks of the pointer being accessed. All that it does is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) * to report when the access failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * Also, this function runs in atomic context, so __put_user() is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) * allowed to sleep. The page-fault handler detects that it is running
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) * in atomic context and will not try to take mmap_sem and handle the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * fault, so additional pagefault_enable()/disable() calls are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * The access can't be done via copy_to_user() here because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * vc_write_mem() must not use string instructions to access unsafe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * memory. The reason is that MOVS is emulated by the #VC handler by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) * splitting the move up into a read and a write and taking a nested #VC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) * exception on whatever of them is the MMIO access. Using string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * instructions here would cause infinite nesting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) switch (size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) case 1: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) u8 d1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) u8 __user *target = (u8 __user *)dst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) memcpy(&d1, buf, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) if (__put_user(d1, target))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) case 2: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) u16 d2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) u16 __user *target = (u16 __user *)dst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) memcpy(&d2, buf, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) if (__put_user(d2, target))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) case 4: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) u32 d4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) u32 __user *target = (u32 __user *)dst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) memcpy(&d4, buf, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) if (__put_user(d4, target))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) case 8: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) u64 d8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) u64 __user *target = (u64 __user *)dst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) memcpy(&d8, buf, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) if (__put_user(d8, target))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) return ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) fault:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) if (user_mode(ctxt->regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) error_code |= X86_PF_USER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) ctxt->fi.vector = X86_TRAP_PF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) ctxt->fi.error_code = error_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) ctxt->fi.cr2 = (unsigned long)dst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) char *src, char *buf, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) unsigned long error_code = X86_PF_PROT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * This function uses __get_user() independent of whether kernel or user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * memory is accessed. This works fine because __get_user() does no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) * sanity checks of the pointer being accessed. All that it does is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) * to report when the access failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * Also, this function runs in atomic context, so __get_user() is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) * allowed to sleep. The page-fault handler detects that it is running
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * in atomic context and will not try to take mmap_sem and handle the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) * fault, so additional pagefault_enable()/disable() calls are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) * The access can't be done via copy_from_user() here because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * vc_read_mem() must not use string instructions to access unsafe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * memory. The reason is that MOVS is emulated by the #VC handler by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * splitting the move up into a read and a write and taking a nested #VC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) * exception on whatever of them is the MMIO access. Using string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * instructions here would cause infinite nesting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) switch (size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) case 1: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) u8 d1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) u8 __user *s = (u8 __user *)src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) if (__get_user(d1, s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) memcpy(buf, &d1, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) case 2: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) u16 d2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) u16 __user *s = (u16 __user *)src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if (__get_user(d2, s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) memcpy(buf, &d2, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) case 4: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) u32 d4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) u32 __user *s = (u32 __user *)src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) if (__get_user(d4, s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) memcpy(buf, &d4, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) case 8: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) u64 d8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) u64 __user *s = (u64 __user *)src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) if (__get_user(d8, s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) goto fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) memcpy(buf, &d8, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) return ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) fault:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) if (user_mode(ctxt->regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) error_code |= X86_PF_USER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) ctxt->fi.vector = X86_TRAP_PF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) ctxt->fi.error_code = error_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) ctxt->fi.cr2 = (unsigned long)src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) unsigned long vaddr, phys_addr_t *paddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) unsigned long va = (unsigned long)vaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) unsigned int level;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) phys_addr_t pa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) pgd_t *pgd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) pte_t *pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) pgd = __va(read_cr3_pa());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) pgd = &pgd[pgd_index(va)];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) pte = lookup_address_in_pgd(pgd, va, &level);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) if (!pte) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) ctxt->fi.vector = X86_TRAP_PF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) ctxt->fi.cr2 = vaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) ctxt->fi.error_code = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) if (user_mode(ctxt->regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) ctxt->fi.error_code |= X86_PF_USER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) if (WARN_ON_ONCE(pte_val(*pte) & _PAGE_ENC))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) /* Emulated MMIO to/from encrypted memory not supported */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) pa = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) pa |= va & ~page_level_mask(level);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) *paddr = pa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) /* Include code shared with pre-decompression boot stage */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) #include "sev-es-shared.c"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) static noinstr void __sev_put_ghcb(struct ghcb_state *state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) struct sev_es_runtime_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) WARN_ON(!irqs_disabled());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) data = this_cpu_read(runtime_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) ghcb = &data->ghcb_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (state->ghcb) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) /* Restore GHCB from Backup */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) *ghcb = *state->ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) data->backup_ghcb_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) state->ghcb = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) * Invalidate the GHCB so a VMGEXIT instruction issued
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) * from userspace won't appear to be valid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) vc_ghcb_invalidate(ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) data->ghcb_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) void noinstr __sev_es_nmi_complete(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) struct ghcb_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) ghcb = __sev_get_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) vc_ghcb_invalidate(ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_NMI_COMPLETE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) ghcb_set_sw_exit_info_1(ghcb, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) ghcb_set_sw_exit_info_2(ghcb, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) sev_es_wr_ghcb_msr(__pa_nodebug(ghcb));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) VMGEXIT();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) __sev_put_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) static u64 get_jump_table_addr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) struct ghcb_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) u64 ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) ghcb = __sev_get_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) vc_ghcb_invalidate(ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_JUMP_TABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) ghcb_set_sw_exit_info_1(ghcb, SVM_VMGEXIT_GET_AP_JUMP_TABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) ghcb_set_sw_exit_info_2(ghcb, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) sev_es_wr_ghcb_msr(__pa(ghcb));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) VMGEXIT();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) if (ghcb_sw_exit_info_1_is_valid(ghcb) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) ghcb_sw_exit_info_2_is_valid(ghcb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) ret = ghcb->save.sw_exit_info_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) __sev_put_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) int sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) u16 startup_cs, startup_ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) phys_addr_t jump_table_pa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) u64 jump_table_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) u16 __iomem *jump_table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) jump_table_addr = get_jump_table_addr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) /* On UP guests there is no jump table so this is not a failure */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) if (!jump_table_addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) /* Check if AP Jump Table is page-aligned */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) if (jump_table_addr & ~PAGE_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) jump_table_pa = jump_table_addr & PAGE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) startup_cs = (u16)(rmh->trampoline_start >> 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) startup_ip = (u16)(rmh->sev_es_trampoline_start -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) rmh->trampoline_start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) jump_table = ioremap_encrypted(jump_table_pa, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) if (!jump_table)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) writew(startup_ip, &jump_table[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) writew(startup_cs, &jump_table[1]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) iounmap(jump_table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) * This is needed by the OVMF UEFI firmware which will use whatever it finds in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) * the GHCB MSR as its GHCB to talk to the hypervisor. So make sure the per-cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) * runtime GHCBs used by the kernel are also mapped in the EFI page-table.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) struct sev_es_runtime_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) unsigned long address, pflags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) u64 pfn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) if (!sev_es_active())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) pflags = _PAGE_NX | _PAGE_RW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) data = per_cpu(runtime_data, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) address = __pa(&data->ghcb_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) pfn = address >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) struct pt_regs *regs = ctxt->regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) u64 exit_info_1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) /* Is it a WRMSR? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) exit_info_1 = (ctxt->insn.opcode.bytes[1] == 0x30) ? 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) ghcb_set_rcx(ghcb, regs->cx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) if (exit_info_1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) ghcb_set_rax(ghcb, regs->ax);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) ghcb_set_rdx(ghcb, regs->dx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) if ((ret == ES_OK) && (!exit_info_1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) regs->ax = ghcb->save.rax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) regs->dx = ghcb->save.rdx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) * This function runs on the first #VC exception after the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) * switched to virtual addresses.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) static bool __init sev_es_setup_ghcb(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) /* First make sure the hypervisor talks a supported protocol. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) if (!sev_es_negotiate_protocol())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) * Clear the boot_ghcb. The first exception comes in before the bss
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) * section is cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) memset(&boot_ghcb_page, 0, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) /* Alright - Make the boot-ghcb public */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) boot_ghcb = &boot_ghcb_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) #ifdef CONFIG_HOTPLUG_CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) static void sev_es_ap_hlt_loop(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) struct ghcb_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) ghcb = __sev_get_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) while (true) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) vc_ghcb_invalidate(ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_HLT_LOOP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) ghcb_set_sw_exit_info_1(ghcb, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) ghcb_set_sw_exit_info_2(ghcb, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) sev_es_wr_ghcb_msr(__pa(ghcb));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) VMGEXIT();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) /* Wakeup signal? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) if (ghcb_sw_exit_info_2_is_valid(ghcb) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) ghcb->save.sw_exit_info_2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) __sev_put_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) * Play_dead handler when running under SEV-ES. This is needed because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) * the hypervisor can't deliver an SIPI request to restart the AP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) * Instead the kernel has to issue a VMGEXIT to halt the VCPU until the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) * hypervisor wakes it up again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) static void sev_es_play_dead(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) play_dead_common();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) /* IRQs now disabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) sev_es_ap_hlt_loop();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) * If we get here, the VCPU was woken up again. Jump to CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) * startup code to get it back online.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) start_cpu0();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) #else /* CONFIG_HOTPLUG_CPU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) #define sev_es_play_dead native_play_dead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) #endif /* CONFIG_HOTPLUG_CPU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) static void __init sev_es_setup_play_dead(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) smp_ops.play_dead = sev_es_play_dead;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) static inline void sev_es_setup_play_dead(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) static void __init alloc_runtime_data(int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) struct sev_es_runtime_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) data = memblock_alloc(sizeof(*data), PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) if (!data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) panic("Can't allocate SEV-ES runtime data");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) per_cpu(runtime_data, cpu) = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) static void __init init_ghcb(int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) struct sev_es_runtime_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) data = per_cpu(runtime_data, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) err = early_set_memory_decrypted((unsigned long)&data->ghcb_page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) sizeof(data->ghcb_page));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) panic("Can't map GHCBs unencrypted");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) memset(&data->ghcb_page, 0, sizeof(data->ghcb_page));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) data->ghcb_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) data->backup_ghcb_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) void __init sev_es_init_vc_handling(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) if (!sev_es_active())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) if (!sev_es_check_cpu_features())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) panic("SEV-ES CPU Features missing");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) /* Enable SEV-ES special handling */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) static_branch_enable(&sev_es_enable_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) /* Initialize per-cpu GHCB pages */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) alloc_runtime_data(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) init_ghcb(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) sev_es_setup_play_dead();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) /* Secondary CPUs use the runtime #VC handler */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) initial_vc_handler = (unsigned long)kernel_exc_vmm_communication;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) int trapnr = ctxt->fi.vector;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) if (trapnr == X86_TRAP_PF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) native_write_cr2(ctxt->fi.cr2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) ctxt->regs->orig_ax = ctxt->fi.error_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) do_early_exception(ctxt->regs, trapnr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) static long *vc_insn_get_reg(struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) long *reg_array;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) reg_array = (long *)ctxt->regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) offset = insn_get_modrm_reg_off(&ctxt->insn, ctxt->regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) if (offset < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) offset /= sizeof(long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) return reg_array + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) static long *vc_insn_get_rm(struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) long *reg_array;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) reg_array = (long *)ctxt->regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) offset = insn_get_modrm_rm_off(&ctxt->insn, ctxt->regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) if (offset < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) offset /= sizeof(long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) return reg_array + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) unsigned int bytes, bool read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) u64 exit_code, exit_info_1, exit_info_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) unsigned long ghcb_pa = __pa(ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) enum es_result res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) phys_addr_t paddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) void __user *ref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) ref = insn_get_addr_ref(&ctxt->insn, ctxt->regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) if (ref == (void __user *)-1L)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) return ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) exit_code = read ? SVM_VMGEXIT_MMIO_READ : SVM_VMGEXIT_MMIO_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) res = vc_slow_virt_to_phys(ghcb, ctxt, (unsigned long)ref, &paddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) if (res != ES_OK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) if (res == ES_EXCEPTION && !read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) ctxt->fi.error_code |= X86_PF_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) exit_info_1 = paddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) /* Can never be greater than 8 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) exit_info_2 = bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) struct insn *insn = &ctxt->insn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) unsigned int bytes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) int sign_byte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) long *reg_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) switch (insn->opcode.bytes[1]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) /* MMIO Read w/ zero-extension */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) case 0xb6:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) case 0xb7:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) if (!bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) bytes = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) ret = vc_do_mmio(ghcb, ctxt, bytes, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) /* Zero extend based on operand size */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) reg_data = vc_insn_get_reg(ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) if (!reg_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) memset(reg_data, 0, insn->opnd_bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) memcpy(reg_data, ghcb->shared_buffer, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) /* MMIO Read w/ sign-extension */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) case 0xbe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) case 0xbf:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) if (!bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) bytes = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) ret = vc_do_mmio(ghcb, ctxt, bytes, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) /* Sign extend based on operand size */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) reg_data = vc_insn_get_reg(ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) if (!reg_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) if (bytes == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) u8 *val = (u8 *)ghcb->shared_buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) sign_byte = (*val & 0x80) ? 0xff : 0x00;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) u16 *val = (u16 *)ghcb->shared_buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) sign_byte = (*val & 0x8000) ? 0xff : 0x00;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) memset(reg_data, sign_byte, insn->opnd_bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) memcpy(reg_data, ghcb->shared_buffer, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) ret = ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) * The MOVS instruction has two memory operands, which raises the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) * problem that it is not known whether the access to the source or the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) * destination caused the #VC exception (and hence whether an MMIO read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) * or write operation needs to be emulated).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) * Instead of playing games with walking page-tables and trying to guess
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) * whether the source or destination is an MMIO range, split the move
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) * into two operations, a read and a write with only one memory operand.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) * This will cause a nested #VC exception on the MMIO address which can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) * then be handled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) * This implementation has the benefit that it also supports MOVS where
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) * source _and_ destination are MMIO regions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) * It will slow MOVS on MMIO down a lot, but in SEV-ES guests it is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) * rare operation. If it turns out to be a performance problem the split
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) * operations can be moved to memcpy_fromio() and memcpy_toio().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) unsigned int bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) unsigned long ds_base, es_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) unsigned char *src, *dst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) unsigned char buffer[8];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) bool rep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) int off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) ds_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_DS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) if (ds_base == -1L || es_base == -1L) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) ctxt->fi.vector = X86_TRAP_GP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) ctxt->fi.error_code = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) src = ds_base + (unsigned char *)ctxt->regs->si;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) dst = es_base + (unsigned char *)ctxt->regs->di;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) ret = vc_read_mem(ctxt, src, buffer, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) if (ret != ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) ret = vc_write_mem(ctxt, dst, buffer, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) if (ret != ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) if (ctxt->regs->flags & X86_EFLAGS_DF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) off = -bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) off = bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) ctxt->regs->si += off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) ctxt->regs->di += off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) rep = insn_has_rep_prefix(&ctxt->insn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) if (rep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) ctxt->regs->cx -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) if (!rep || ctxt->regs->cx == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) return ES_RETRY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) static enum es_result vc_handle_mmio(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) struct insn *insn = &ctxt->insn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) unsigned int bytes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) long *reg_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) switch (insn->opcode.bytes[0]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) /* MMIO Write */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) case 0x88:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) case 0x89:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) if (!bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) bytes = insn->opnd_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) reg_data = vc_insn_get_reg(ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) if (!reg_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) memcpy(ghcb->shared_buffer, reg_data, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) ret = vc_do_mmio(ghcb, ctxt, bytes, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) case 0xc6:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) case 0xc7:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) if (!bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) bytes = insn->opnd_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) ret = vc_do_mmio(ghcb, ctxt, bytes, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) /* MMIO Read */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) case 0x8a:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) case 0x8b:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) if (!bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) bytes = insn->opnd_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) ret = vc_do_mmio(ghcb, ctxt, bytes, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) reg_data = vc_insn_get_reg(ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) if (!reg_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) /* Zero-extend for 32-bit operation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) if (bytes == 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) *reg_data = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) memcpy(reg_data, ghcb->shared_buffer, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) /* MOVS instruction */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) case 0xa4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) case 0xa5:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) if (!bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) bytes = insn->opnd_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) ret = vc_handle_mmio_movs(ctxt, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) /* Two-Byte Opcodes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) case 0x0f:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) ret = vc_handle_mmio_twobyte_ops(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) ret = ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) long val, *reg = vc_insn_get_rm(ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) if (!reg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) val = *reg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) /* Upper 32 bits must be written as zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) if (val >> 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) ctxt->fi.vector = X86_TRAP_GP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) ctxt->fi.error_code = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) /* Clear out other reserved bits and set bit 10 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) val = (val & 0xffff23ffL) | BIT(10);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) /* Early non-zero writes to DR7 are not supported */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) if (!data && (val & ~DR7_RESET_VALUE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) return ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) /* Using a value of 0 for ExitInfo1 means RAX holds the value */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) ghcb_set_rax(ghcb, val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) if (ret != ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) if (data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) data->dr7 = val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) long *reg = vc_insn_get_rm(ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) if (!reg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) return ES_DECODE_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) if (data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) *reg = data->dr7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) *reg = DR7_RESET_VALUE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) ghcb_set_rcx(ghcb, ctxt->regs->cx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) if (ret != ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) return ES_VMM_ERROR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) ctxt->regs->ax = ghcb->save.rax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) ctxt->regs->dx = ghcb->save.rdx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) static enum es_result vc_handle_monitor(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) * Treat it as a NOP and do not leak a physical address to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) * hypervisor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) static enum es_result vc_handle_mwait(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) /* Treat the same as MONITOR/MONITORX */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) enum es_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) ghcb_set_rax(ghcb, ctxt->regs->ax);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) ghcb_set_cpl(ghcb, user_mode(ctxt->regs) ? 3 : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) if (x86_platform.hyper.sev_es_hcall_prepare)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) if (ret != ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) if (!ghcb_rax_is_valid(ghcb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) return ES_VMM_ERROR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) ctxt->regs->ax = ghcb->save.rax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) * Call sev_es_hcall_finish() after regs->ax is already set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) * This allows the hypervisor handler to overwrite it again if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) * necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) if (x86_platform.hyper.sev_es_hcall_finish &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) !x86_platform.hyper.sev_es_hcall_finish(ghcb, ctxt->regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) return ES_VMM_ERROR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) return ES_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) static enum es_result vc_handle_trap_ac(struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) * Calling ecx_alignment_check() directly does not work, because it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) * enables IRQs and the GHCB is active. Forward the exception and call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) * it later from vc_forward_exception().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) ctxt->fi.vector = X86_TRAP_AC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) ctxt->fi.error_code = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) return ES_EXCEPTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) struct ghcb *ghcb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) unsigned long exit_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) enum es_result result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) switch (exit_code) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) case SVM_EXIT_READ_DR7:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) result = vc_handle_dr7_read(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) case SVM_EXIT_WRITE_DR7:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) result = vc_handle_dr7_write(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) case SVM_EXIT_EXCP_BASE + X86_TRAP_AC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) result = vc_handle_trap_ac(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) case SVM_EXIT_RDTSC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) case SVM_EXIT_RDTSCP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) case SVM_EXIT_RDPMC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) result = vc_handle_rdpmc(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) case SVM_EXIT_INVD:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) pr_err_ratelimited("#VC exception for INVD??? Seriously???\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) result = ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) case SVM_EXIT_CPUID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) result = vc_handle_cpuid(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) case SVM_EXIT_IOIO:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) result = vc_handle_ioio(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) case SVM_EXIT_MSR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) result = vc_handle_msr(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) case SVM_EXIT_VMMCALL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) result = vc_handle_vmmcall(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) case SVM_EXIT_WBINVD:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) result = vc_handle_wbinvd(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) case SVM_EXIT_MONITOR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) result = vc_handle_monitor(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) case SVM_EXIT_MWAIT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) result = vc_handle_mwait(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) case SVM_EXIT_NPF:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) result = vc_handle_mmio(ghcb, ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) * Unexpected #VC exception
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) result = ES_UNSUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) return result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) long error_code = ctxt->fi.error_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) int trapnr = ctxt->fi.vector;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) ctxt->regs->orig_ax = ctxt->fi.error_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) switch (trapnr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) case X86_TRAP_GP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) exc_general_protection(ctxt->regs, error_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) case X86_TRAP_UD:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) exc_invalid_op(ctxt->regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) case X86_TRAP_PF:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) write_cr2(ctxt->fi.cr2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) exc_page_fault(ctxt->regs, error_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) case X86_TRAP_AC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) exc_alignment_check(ctxt->regs, error_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) static __always_inline bool on_vc_fallback_stack(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) unsigned long sp = (unsigned long)regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) static bool vc_raw_handle_exception(struct pt_regs *regs, unsigned long error_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) struct ghcb_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) struct es_em_ctxt ctxt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) enum es_result result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) struct ghcb *ghcb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) bool ret = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) ghcb = __sev_get_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) vc_ghcb_invalidate(ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) result = vc_init_em_ctxt(&ctxt, regs, error_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) if (result == ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) result = vc_handle_exitcode(&ctxt, ghcb, error_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) __sev_put_ghcb(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) /* Done - now check the result */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) switch (result) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) case ES_OK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) vc_finish_insn(&ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) case ES_UNSUPPORTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) pr_err_ratelimited("Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) error_code, regs->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) ret = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) case ES_VMM_ERROR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) pr_err_ratelimited("Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) error_code, regs->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) ret = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) case ES_DECODE_FAILED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) pr_err_ratelimited("Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) error_code, regs->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) ret = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) case ES_EXCEPTION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) vc_forward_exception(&ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) case ES_RETRY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) /* Nothing to do */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) pr_emerg("Unknown result in %s():%d\n", __func__, result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) * Emulating the instruction which caused the #VC exception
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) * failed - can't continue so print debug information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) static __always_inline bool vc_is_db(unsigned long error_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) return error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) * Runtime #VC exception handler when raised from kernel mode. Runs in NMI mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) * and will panic when an error happens.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) irqentry_state_t irq_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) * With the current implementation it is always possible to switch to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) * safe stack because #VC exceptions only happen at known places, like
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) * intercepted instructions or accesses to MMIO areas/IO ports. They can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) * also happen with code instrumentation when the hypervisor intercepts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) * #DB, but the critical paths are forbidden to be instrumented, so #DB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) * exceptions currently also only happen in safe places.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) * But keep this here in case the noinstr annotations are violated due
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) * to bug elsewhere.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) if (unlikely(on_vc_fallback_stack(regs))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) instrumentation_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) panic("Can't handle #VC exception from unsupported context\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) instrumentation_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) * Handle #DB before calling into !noinstr code to avoid recursive #DB.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) if (vc_is_db(error_code)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) exc_debug(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) irq_state = irqentry_nmi_enter(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) instrumentation_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) if (!vc_raw_handle_exception(regs, error_code)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) /* Show some debug info */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) show_regs(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) /* Ask hypervisor to sev_es_terminate */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) /* If that fails and we get here - just panic */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) panic("Returned from Terminate-Request to Hypervisor\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) instrumentation_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) irqentry_nmi_exit(regs, irq_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) * Runtime #VC exception handler when raised from user mode. Runs in IRQ mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) * and will kill the current task with SIGBUS when an error happens.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) DEFINE_IDTENTRY_VC_USER(exc_vmm_communication)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) * Handle #DB before calling into !noinstr code to avoid recursive #DB.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) if (vc_is_db(error_code)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) noist_exc_debug(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) irqentry_enter_from_user_mode(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) instrumentation_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) if (!vc_raw_handle_exception(regs, error_code)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) * Do not kill the machine if user-space triggered the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) * exception. Send SIGBUS instead and let user-space deal with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) * it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) instrumentation_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) irqentry_exit_to_user_mode(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) unsigned long exit_code = regs->orig_ax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) struct es_em_ctxt ctxt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) enum es_result result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) /* Do initial setup or terminate the guest */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) vc_ghcb_invalidate(boot_ghcb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) result = vc_init_em_ctxt(&ctxt, regs, exit_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) if (result == ES_OK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) result = vc_handle_exitcode(&ctxt, boot_ghcb, exit_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) /* Done - now check the result */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) switch (result) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) case ES_OK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) vc_finish_insn(&ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) case ES_UNSUPPORTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) early_printk("PANIC: Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) exit_code, regs->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) case ES_VMM_ERROR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) early_printk("PANIC: Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) exit_code, regs->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) case ES_DECODE_FAILED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) early_printk("PANIC: Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) exit_code, regs->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) case ES_EXCEPTION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) vc_early_forward_exception(&ctxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) case ES_RETRY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) /* Nothing to do */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) show_regs(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) while (true)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) halt();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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