* [RFC PATCH pve-qemu] savevm-async: fix stuck paused vm after snapshot
@ 2026-06-12 7:53 Erik Fastermann
2026-08-26 13:30 ` Fiona Ebner
0 siblings, 1 reply; 2+ messages in thread
From: Erik Fastermann @ 2026-06-12 7:53 UTC (permalink / raw)
To: pve-devel; +Cc: Erik Fastermann
When creating a snapshot of a paused vm, the vm hung indefinitely in the
state "paused (finish-migrate)" and had to be restarted. This patch
fixes this by only transitioning the vm run state if the vm was
currently running.
Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
---
...c-fix-stuck-paused-vm-after-snapshot.patch | 48 +++++++++++++++++++
debian/patches/series | 1 +
2 files changed, 49 insertions(+)
create mode 100644 debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
diff --git a/debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch b/debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
new file mode 100644
index 0000000..46f0422
--- /dev/null
+++ b/debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
@@ -0,0 +1,48 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Erik Fastermann <e.fastermann@proxmox.com>
+Date: Thu, 11 Jun 2026 13:42:05 +0200
+Subject: [PATCH] savevm-async: fix stuck paused vm after snapshot
+
+When creating a snapshot of a paused vm, the vm hung indefinitely in the
+state "paused (finish-migrate)" and had to be restarted. This patch
+fixes this by only transitioning the vm run state if the vm was
+currently running.
+
+Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
+---
+ migration/savevm-async.c | 12 ++++++++----
+ 1 file changed, 8 insertions(+), 4 deletions(-)
+
+diff --git a/migration/savevm-async.c b/migration/savevm-async.c
+index acd1a4de6e..153433f539 100644
+--- a/migration/savevm-async.c
++++ b/migration/savevm-async.c
+@@ -181,9 +181,11 @@ static void process_savevm_finalize(void *opaque)
+ blk_set_aio_context(snap_state.target, qemu_get_aio_context(), NULL);
+
+ snap_state.vm_needs_start = runstate_is_running();
+- ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+- if (ret < 0) {
+- save_snapshot_error("vm_stop_force_state error %d", ret);
++ if (snap_state.vm_needs_start) {
++ ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
++ if (ret < 0) {
++ save_snapshot_error("vm_stop_force_state error %d", ret);
++ }
+ }
+
+ if (!aborted) {
+@@ -370,7 +372,9 @@ void qmp_savevm_start(const char *statefile, Error **errp)
+
+ if (!statefile) {
+ snap_state.vm_needs_start = runstate_is_running();
+- vm_stop(RUN_STATE_SAVE_VM);
++ if (snap_state.vm_needs_start) {
++ vm_stop(RUN_STATE_SAVE_VM);
++ }
+ snap_state.state = SAVE_STATE_COMPLETED;
+ return;
+ }
+--
+2.47.3
+
diff --git a/debian/patches/series b/debian/patches/series
index 84c0664..6463a4a 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -70,3 +70,4 @@ pve/0043-PVE-backup-get-device-info-allow-caller-to-specify-f.patch
pve/0044-PVE-backup-implement-backup-access-setup-and-teardow.patch
pve/0045-PVE-backup-prepare-for-the-switch-to-using-blockdev-.patch
pve/0046-savevm-async-reuse-migration-blocker-check-for-snaps.patch
+pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
--
2.47.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [RFC PATCH pve-qemu] savevm-async: fix stuck paused vm after snapshot
2026-06-12 7:53 [RFC PATCH pve-qemu] savevm-async: fix stuck paused vm after snapshot Erik Fastermann
@ 2026-08-26 13:30 ` Fiona Ebner
0 siblings, 0 replies; 2+ messages in thread
From: Fiona Ebner @ 2026-08-26 13:30 UTC (permalink / raw)
To: Erik Fastermann, pve-devel
Am 12.06.26 um 9:53 AM schrieb Erik Fastermann:
> When creating a snapshot of a paused vm, the vm hung indefinitely in the
> state "paused (finish-migrate)" and had to be restarted. This patch
> fixes this by only transitioning the vm run state if the vm was
> currently running.
>
> Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
> ---
> ...c-fix-stuck-paused-vm-after-snapshot.patch | 48 +++++++++++++++++++
> debian/patches/series | 1 +
> 2 files changed, 49 insertions(+)
> create mode 100644 debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
>
> diff --git a/debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch b/debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
> new file mode 100644
> index 0000000..46f0422
> --- /dev/null
> +++ b/debian/patches/pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
> @@ -0,0 +1,48 @@
> +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
> +From: Erik Fastermann <e.fastermann@proxmox.com>
> +Date: Thu, 11 Jun 2026 13:42:05 +0200
> +Subject: [PATCH] savevm-async: fix stuck paused vm after snapshot
> +
> +When creating a snapshot of a paused vm, the vm hung indefinitely in the
> +state "paused (finish-migrate)" and had to be restarted. This patch
> +fixes this by only transitioning the vm run state if the vm was
> +currently running.
> +
> +Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
> +---
> + migration/savevm-async.c | 12 ++++++++----
> + 1 file changed, 8 insertions(+), 4 deletions(-)
> +
> +diff --git a/migration/savevm-async.c b/migration/savevm-async.c
> +index acd1a4de6e..153433f539 100644
> +--- a/migration/savevm-async.c
> ++++ b/migration/savevm-async.c
> +@@ -181,9 +181,11 @@ static void process_savevm_finalize(void *opaque)
> + blk_set_aio_context(snap_state.target, qemu_get_aio_context(), NULL);
> +
> + snap_state.vm_needs_start = runstate_is_running();
> +- ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
> +- if (ret < 0) {
> +- save_snapshot_error("vm_stop_force_state error %d", ret);
> ++ if (snap_state.vm_needs_start) {
> ++ ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
It feels wrong to me to avoid going into the finish-migrate state, since
we do things like qemu_savevm_state_complete_precopy(),
qemu_savevm_state_cleanup() and save_snapshot_cleanup() below.
In migration/migration.c there is
if (runstate_is_live(s->vm_old_state)) {
if (!runstate_check(RUN_STATE_SHUTDOWN)) {
vm_start();
}
} else {
if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
runstate_set(s->vm_old_state);
}
}
The old state is saved via runstate_get() in migration_stop_vm() before
stopping the VM. I think we should do the same.
> ++ if (ret < 0) {
> ++ save_snapshot_error("vm_stop_force_state error %d", ret);
> ++ }
> + }
> +
> + if (!aborted) {
> +@@ -370,7 +372,9 @@ void qmp_savevm_start(const char *statefile, Error **errp)
> +
> + if (!statefile) {
> + snap_state.vm_needs_start = runstate_is_running();
And for us, the place to store the old state is here.
> +- vm_stop(RUN_STATE_SAVE_VM);
> ++ if (snap_state.vm_needs_start) {
> ++ vm_stop(RUN_STATE_SAVE_VM);
> ++ }
> + snap_state.state = SAVE_STATE_COMPLETED;
> + return;
> + }
> +--
> +2.47.3
> +
> diff --git a/debian/patches/series b/debian/patches/series
> index 84c0664..6463a4a 100644
> --- a/debian/patches/series
> +++ b/debian/patches/series
> @@ -70,3 +70,4 @@ pve/0043-PVE-backup-get-device-info-allow-caller-to-specify-f.patch
> pve/0044-PVE-backup-implement-backup-access-setup-and-teardow.patch
> pve/0045-PVE-backup-prepare-for-the-switch-to-using-blockdev-.patch
> pve/0046-savevm-async-reuse-migration-blocker-check-for-snaps.patch
> +pve/0047-savevm-async-fix-stuck-paused-vm-after-snapshot.patch
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