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Diffstat (limited to 'Documentation/virtual/kvm/devices')
| -rw-r--r-- | Documentation/virtual/kvm/devices/xive.txt | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt index 1e7f19d7594b..7ffd4c7be7b5 100644 --- a/Documentation/virtual/kvm/devices/xive.txt +++ b/Documentation/virtual/kvm/devices/xive.txt @@ -23,6 +23,12 @@ the legacy interrupt mode, referred as XICS (POWER7/8). queues. To be used by kexec and kdump. Errors: none + 1.2 KVM_DEV_XIVE_EQ_SYNC (write only) + Sync all the sources and queues and mark the EQ pages dirty. This + to make sure that a consistent memory state is captured when + migrating the VM. + Errors: none + 2. KVM_DEV_XIVE_GRP_SOURCE (write only) Initializes a new source in the XIVE device and mask it. Attributes: @@ -100,3 +106,26 @@ the legacy interrupt mode, referred as XICS (POWER7/8). Errors: -ENOENT: Unknown source number -EINVAL: Not initialized source number + +* Migration: + + Saving the state of a VM using the XIVE native exploitation mode + should follow a specific sequence. When the VM is stopped : + + 1. Mask all sources (PQ=01) to stop the flow of events. + + 2. Sync the XIVE device with the KVM control KVM_DEV_XIVE_EQ_SYNC to + flush any in-flight event notification and to stabilize the EQs. At + this stage, the EQ pages are marked dirty to make sure they are + transferred in the migration sequence. + + 3. Capture the state of the source targeting, the EQs configuration + and the state of thread interrupt context registers. + + Restore is similar : + + 1. Restore the EQ configuration. As targeting depends on it. + 2. Restore targeting + 3. Restore the thread interrupt contexts + 4. Restore the source states + 5. Let the vCPU run |