From b9ae473d80302519a7b89f98795a80abfea1deea Mon Sep 17 00:00:00 2001 From: Steve Sistare Date: Wed, 3 Jan 2024 12:05:31 -0800 Subject: cpus: stop vm in suspended runstate Currently, a vm in the suspended state is not completely stopped. The VCPUs have been paused, but the cpu clock still runs, and runstate notifiers for the transition to stopped have not been called. This causes problems for live migration. Stale cpu timers_state is saved to the migration stream, causing time errors in the guest when it wakes from suspend, and state that would have been modified by runstate notifiers is wrong. Modify vm_stop to completely stop the vm if the current state is suspended, transition to RUN_STATE_PAUSED, and remember that the machine was suspended. Modify vm_start to restore the suspended state. This affects all callers of vm_stop and vm_start, notably, the qapi stop and cont commands: old behavior: RUN_STATE_SUSPENDED --> stop --> RUN_STATE_SUSPENDED new behavior: RUN_STATE_SUSPENDED --> stop --> RUN_STATE_PAUSED RUN_STATE_PAUSED --> cont --> RUN_STATE_SUSPENDED For example: (qemu) info status VM status: paused (suspended) (qemu) stop (qemu) info status VM status: paused (qemu) system_wakeup Error: Unable to wake up: guest is not in suspended state (qemu) cont (qemu) info status VM status: paused (suspended) (qemu) system_wakeup (qemu) info status VM status: running Suggested-by: Peter Xu Signed-off-by: Steve Sistare Reviewed-by: Peter Xu Link: https://lore.kernel.org/r/1704312341-66640-3-git-send-email-steven.sistare@oracle.com Signed-off-by: Peter Xu --- qapi/misc.json | 11 +++++++++-- qapi/run-state.json | 6 +++--- 2 files changed, 12 insertions(+), 5 deletions(-) (limited to 'qapi') diff --git a/qapi/misc.json b/qapi/misc.json index cda2effa81..3622d98d01 100644 --- a/qapi/misc.json +++ b/qapi/misc.json @@ -134,7 +134,7 @@ ## # @stop: # -# Stop all guest VCPU execution. +# Stop guest VM execution. # # Since: 0.14 # @@ -143,6 +143,9 @@ # the guest remains paused once migration finishes, as if the -S # option was passed on the command line. # +# In the "suspended" state, it will completely stop the VM and +# cause a transition to the "paused" state. (Since 9.0) +# # Example: # # -> { "execute": "stop" } @@ -153,7 +156,7 @@ ## # @cont: # -# Resume guest VCPU execution. +# Resume guest VM execution. # # Since: 0.14 # @@ -165,6 +168,10 @@ # guest starts once migration finishes, removing the effect of the # -S command line option if it was passed. # +# If the VM was previously suspended, and not been reset or woken, +# this command will transition back to the "suspended" state. +# (Since 9.0) +# # Example: # # -> { "execute": "cont" } diff --git a/qapi/run-state.json b/qapi/run-state.json index f216ba54ec..ca05502e0a 100644 --- a/qapi/run-state.json +++ b/qapi/run-state.json @@ -102,7 +102,7 @@ ## # @StatusInfo: # -# Information about VCPU run state +# Information about VM run state # # @running: true if all VCPUs are runnable, false if not runnable # @@ -130,9 +130,9 @@ ## # @query-status: # -# Query the run status of all VCPUs +# Query the run status of the VM # -# Returns: @StatusInfo reflecting all VCPUs +# Returns: @StatusInfo reflecting the VM # # Since: 0.14 # -- cgit v1.2.3