Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) .. SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) ===========================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) POWER9 eXternal Interrupt Virtualization Engine (XIVE Gen1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) ===========================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) Device types supported:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)   - KVM_DEV_TYPE_XIVE     POWER9 XIVE Interrupt Controller generation 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) This device acts as a VM interrupt controller. It provides the KVM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) interface to configure the interrupt sources of a VM in the underlying
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) POWER9 XIVE interrupt controller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) Only one XIVE instance may be instantiated. A guest XIVE device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) requires a POWER9 host and the guest OS should have support for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) XIVE native exploitation interrupt mode. If not, it should run using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) the legacy interrupt mode, referred as XICS (POWER7/8).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) * Device Mappings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)   The KVM device exposes different MMIO ranges of the XIVE HW which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)   are required for interrupt management. These are exposed to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)   guest in VMAs populated with a custom VM fault handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)   1. Thread Interrupt Management Area (TIMA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)   Each thread has an associated Thread Interrupt Management context
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)   composed of a set of registers. These registers let the thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)   handle priority management and interrupt acknowledgment. The most
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)   important are :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)       - Interrupt Pending Buffer     (IPB)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)       - Current Processor Priority   (CPPR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)       - Notification Source Register (NSR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)   They are exposed to software in four different pages each proposing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)   a view with a different privilege. The first page is for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38)   physical thread context and the second for the hypervisor. Only the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)   third (operating system) and the fourth (user level) are exposed the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40)   guest.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42)   2. Event State Buffer (ESB)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44)   Each source is associated with an Event State Buffer (ESB) with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45)   either a pair of even/odd pair of pages which provides commands to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46)   manage the source: to trigger, to EOI, to turn off the source for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47)   instance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)   3. Device pass-through
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)   When a device is passed-through into the guest, the source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52)   interrupts are from a different HW controller (PHB4) and the ESB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53)   pages exposed to the guest should accommadate this change.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55)   The passthru_irq helpers, kvmppc_xive_set_mapped() and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56)   kvmppc_xive_clr_mapped() are called when the device HW irqs are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57)   mapped into or unmapped from the guest IRQ number space. The KVM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58)   device extends these helpers to clear the ESB pages of the guest IRQ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59)   number being mapped and then lets the VM fault handler repopulate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60)   The handler will insert the ESB page corresponding to the HW
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61)   interrupt of the device being passed-through or the initial IPI ESB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62)   page if the device has being removed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64)   The ESB remapping is fully transparent to the guest and the OS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65)   device driver. All handling is done within VFIO and the above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66)   helpers in KVM-PPC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) * Groups:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 1. KVM_DEV_XIVE_GRP_CTRL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)      Provides global controls on the device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73)   Attributes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74)     1.1 KVM_DEV_XIVE_RESET (write only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75)     Resets the interrupt controller configuration for sources and event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76)     queues. To be used by kexec and kdump.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78)     Errors: none
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80)     1.2 KVM_DEV_XIVE_EQ_SYNC (write only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81)     Sync all the sources and queues and mark the EQ pages dirty. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82)     to make sure that a consistent memory state is captured when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83)     migrating the VM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85)     Errors: none
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87)     1.3 KVM_DEV_XIVE_NR_SERVERS (write only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88)     The kvm_device_attr.addr points to a __u32 value which is the number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89)     interrupt server numbers (ie, highest possible vcpu id plus one).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91)     Errors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93)       =======  ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94)       -EINVAL  Value greater than KVM_MAX_VCPU_ID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95)       -EFAULT  Invalid user pointer for attr->addr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96)       -EBUSY   A vCPU is already connected to the device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97)       =======  ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 2. KVM_DEV_XIVE_GRP_SOURCE (write only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)      Initializes a new source in the XIVE device and mask it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)   Attributes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)     Interrupt source number  (64-bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)   The kvm_device_attr.addr points to a __u64 value::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)     bits:     | 63   ....  2 |   1   |   0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)     values:   |    unused    | level | type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)   - type:  0:MSI 1:LSI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)   - level: assertion level in case of an LSI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)   Errors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)     =======  ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)     -E2BIG   Interrupt source number is out of range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)     -ENOMEM  Could not create a new source block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)     -EFAULT  Invalid user pointer for attr->addr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)     -ENXIO   Could not allocate underlying HW interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)     =======  ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 3. KVM_DEV_XIVE_GRP_SOURCE_CONFIG (write only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)      Configures source targeting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)   Attributes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)     Interrupt source number  (64-bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)   The kvm_device_attr.addr points to a __u64 value::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)     bits:     | 63   ....  33 |  32  | 31 .. 3 |  2 .. 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)     values:   |    eisn       | mask |  server | priority
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)   - priority: 0-7 interrupt priority level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)   - server: CPU number chosen to handle the interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)   - mask: mask flag (unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)   - eisn: Effective Interrupt Source Number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)   Errors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)     =======  =======================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)     -ENOENT  Unknown source number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)     -EINVAL  Not initialized source number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)     -EINVAL  Invalid priority
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)     -EINVAL  Invalid CPU number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)     -EFAULT  Invalid user pointer for attr->addr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)     -ENXIO   CPU event queues not configured or configuration of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	     underlying HW interrupt failed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)     -EBUSY   No CPU available to serve interrupt
^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) 4. KVM_DEV_XIVE_GRP_EQ_CONFIG (read-write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)      Configures an event queue of a CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)   Attributes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)     EQ descriptor identifier (64-bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)   The EQ descriptor identifier is a tuple (server, priority)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)     bits:     | 63   ....  32 | 31 .. 3 |  2 .. 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)     values:   |    unused     |  server | priority
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)   The kvm_device_attr.addr points to::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)     struct kvm_ppc_xive_eq {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	__u32 flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	__u32 qshift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	__u64 qaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	__u32 qtoggle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	__u32 qindex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	__u8  pad[40];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)     };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)   - flags: queue flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)       KVM_XIVE_EQ_ALWAYS_NOTIFY (required)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	forces notification without using the coalescing mechanism
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	provided by the XIVE END ESBs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)   - qshift: queue size (power of 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)   - qaddr: real address of queue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)   - qtoggle: current queue toggle bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)   - qindex: current queue index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)   - pad: reserved for future use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)   Errors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)     =======  =========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)     -ENOENT  Invalid CPU number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)     -EINVAL  Invalid priority
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)     -EINVAL  Invalid flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)     -EINVAL  Invalid queue size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)     -EINVAL  Invalid queue address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)     -EFAULT  Invalid user pointer for attr->addr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)     -EIO     Configuration of the underlying HW failed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)     =======  =========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 5. KVM_DEV_XIVE_GRP_SOURCE_SYNC (write only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)      Synchronize the source to flush event notifications
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)   Attributes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)     Interrupt source number  (64-bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)   Errors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)     =======  =============================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)     -ENOENT  Unknown source number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)     -EINVAL  Not initialized source number
^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) * VCPU state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)   The XIVE IC maintains VP interrupt state in an internal structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)   called the NVT. When a VP is not dispatched on a HW processor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)   thread, this structure can be updated by HW if the VP is the target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)   of an event notification.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)   It is important for migration to capture the cached IPB from the NVT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)   as it synthesizes the priorities of the pending interrupts. We
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)   capture a bit more to report debug information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)   KVM_REG_PPC_VP_STATE (2 * 64bits)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)     bits:     |  63  ....  32  |  31  ....  0  |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)     values:   |   TIMA word0   |   TIMA word1  |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)     bits:     | 127       ..........       64  |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)     values:   |            unused              |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) * Migration:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)   Saving the state of a VM using the XIVE native exploitation mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)   should follow a specific sequence. When the VM is stopped :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231)   1. Mask all sources (PQ=01) to stop the flow of events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)   2. Sync the XIVE device with the KVM control KVM_DEV_XIVE_EQ_SYNC to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)   flush any in-flight event notification and to stabilize the EQs. At
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)   this stage, the EQ pages are marked dirty to make sure they are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)   transferred in the migration sequence.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)   3. Capture the state of the source targeting, the EQs configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)   and the state of thread interrupt context registers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)   Restore is similar:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)   1. Restore the EQ configuration. As targeting depends on it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)   2. Restore targeting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)   3. Restore the thread interrupt contexts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)   4. Restore the source states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)   5. Let the vCPU run