[PATCH qemu-server] fix #7697: snapshot hook name mismatch

[PATCH qemu-server] fix #7697: snapshot hook name mismatch

[Jakob Klocker]

pve-guest-common invokes the snapshot hook with the name
"after-unfreeze" [0], but qemu-server checks for "after-freeze" [1].

As a result, the post-unfreeze hook is never executed and the
query-savevm polling loop intended to wait for savevm-end cleanup
is skipped.

[0] https://git.proxmox.com/?p=pve-guest-common.git;a=blob;f=src/PVE/AbstractConfig.pm;h=7bcae1943094f99e98a8ba19428e1f90d4936080;hb=572ed3533d5ba75e82a5a0e367e2db1aff290c09#l868
[1] https://git.proxmox.com/?p=qemu-server.git;a=blob;f=src/PVE/QemuConfig.pm;h=80a3999e85886b603bdb1b5a8d3d2b3887dff369;hb=bef9334af96eb30cab8d1f5c41c0974eaf0bbdc4#l374

Link: https://bugzilla.proxmox.com/show_bug.cgi?id=7697
Signed-off-by: Jakob Klocker <j.klocker@proxmox.com>
---
 src/PVE/QemuConfig.pm     | 2 +-
 src/test/snapshot-test.pm | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/PVE/QemuConfig.pm b/src/PVE/QemuConfig.pm
index 80a3999e..c24eb835 100644
--- a/src/PVE/QemuConfig.pm
+++ b/src/PVE/QemuConfig.pm
@@ -371,7 +371,7 @@ sub __snapshot_create_vol_snapshots_hook {
                     if $snap->{vmstate};
             };
             warn $@ if $@;
-        } elsif ($hook eq "after-freeze") {
+        } elsif ($hook eq "after-unfreeze") {
             # savevm-end is async, we need to wait
             for (;;) {
                 my $stat = mon_cmd($vmid, "query-savevm");
diff --git a/src/test/snapshot-test.pm b/src/test/snapshot-test.pm
index e28107b9..3e3b9412 100644
--- a/src/test/snapshot-test.pm
+++ b/src/test/snapshot-test.pm
@@ -379,12 +379,13 @@ sub qmp_cmd {
     if ($exec eq "savevm-end") {
         die "savevm-end disabled\n"
             if !$vm_mon->{savevm_end};
+        $vm_mon->{savevm_ended} = 1;
         return;
     }
     if ($exec eq "query-savevm") {
         return {
             "status" => "completed",
-            "bytes" => 1024 * 1024 * 1024,
+            "bytes" => $vm_mon->{savevm_ended} ? 0 : 1024 * 1024 * 1024,
             "total-time" => 5000,
         };
     }
-- 
2.47.3

Re: [PATCH qemu-server] fix #7697: snapshot hook name mismatch

[Arthur Bied-Charreton]

On Fri, Jun 12, 2026 at 12:07:58PM +0200, Jakob Klocker wrote:
> pve-guest-common invokes the snapshot hook with the name
> "after-unfreeze" [0], but qemu-server checks for "after-freeze" [1].
> 
> As a result, the post-unfreeze hook is never executed and the
> query-savevm polling loop intended to wait for savevm-end cleanup
> is skipped.
> 
> [0] https://git.proxmox.com/?p=pve-guest-common.git;a=blob;f=src/PVE/AbstractConfig.pm;h=7bcae1943094f99e98a8ba19428e1f90d4936080;hb=572ed3533d5ba75e82a5a0e367e2db1aff290c09#l868
> [1] https://git.proxmox.com/?p=qemu-server.git;a=blob;f=src/PVE/QemuConfig.pm;h=80a3999e85886b603bdb1b5a8d3d2b3887dff369;hb=bef9334af96eb30cab8d1f5c41c0974eaf0bbdc4#l374
> 
> Link: https://bugzilla.proxmox.com/show_bug.cgi?id=7697
> Signed-off-by: Jakob Klocker <j.klocker@proxmox.com>
> ---
>  src/PVE/QemuConfig.pm     | 2 +-
>  src/test/snapshot-test.pm | 3 ++-
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/src/PVE/QemuConfig.pm b/src/PVE/QemuConfig.pm
> index 80a3999e..c24eb835 100644
> --- a/src/PVE/QemuConfig.pm
> +++ b/src/PVE/QemuConfig.pm
> @@ -371,7 +371,7 @@ sub __snapshot_create_vol_snapshots_hook {
>                      if $snap->{vmstate};
>              };
>              warn $@ if $@;
> -        } elsif ($hook eq "after-freeze") {
> +        } elsif ($hook eq "after-unfreeze") {
>              # savevm-end is async, we need to wait
>              for (;;) {
>                  my $stat = mon_cmd($vmid, "query-savevm");
> diff --git a/src/test/snapshot-test.pm b/src/test/snapshot-test.pm
> index e28107b9..3e3b9412 100644
> --- a/src/test/snapshot-test.pm
> +++ b/src/test/snapshot-test.pm
> @@ -379,12 +379,13 @@ sub qmp_cmd {
>      if ($exec eq "savevm-end") {
>          die "savevm-end disabled\n"
>              if !$vm_mon->{savevm_end};
> +        $vm_mon->{savevm_ended} = 1;
>          return;
>      }
>      if ($exec eq "query-savevm") {
>          return {
>              "status" => "completed",
> -            "bytes" => 1024 * 1024 * 1024,
> +            "bytes" => $vm_mon->{savevm_ended} ? 0 : 1024 * 1024 * 1024,
>              "total-time" => 5000,
>          };
>      }
> -- 
> 2.47.3
> 

I tested the series fixing #5032 [0], which depends on this, and
the after-unfreeze hook is indeed executed. Consider this:

Tested-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>

[0] https://lore.proxmox.com/all/20260612122942.181958-1-j.klocker@proxmox.com/T/#u

Re: [PATCH qemu-server] fix #7697: snapshot hook name mismatch

[Michael Köppl]

Tested this in combination with the fix for #5032 [0]. With this patch
applied, the hook is called as expected.

The changes look simple enough. Had a look at how the hook is called
when a snapshot is made and it seems correct to me that this should be
after-unfreeze.

Consider this:
Tested-by: Michael Köppl <m.koeppl@proxmox.com> 
Reviewed-by: Michael Köppl <m.koeppl@proxmox.com> 

[0] https://lore.proxmox.com/pve-devel/20260622134711.108611-1-j.klocker@proxmox.com/

On Fri Jun 12, 2026 at 12:07 PM CEST, Jakob Klocker wrote:
> pve-guest-common invokes the snapshot hook with the name
> "after-unfreeze" [0], but qemu-server checks for "after-freeze" [1].

[snip]

applied: [PATCH qemu-server] fix #7697: snapshot hook name mismatch

[Fiona Ebner]

On Fri, 12 Jun 2026 12:07:58 +0200, Jakob Klocker wrote:
> pve-guest-common invokes the snapshot hook with the name
> "after-unfreeze" [0], but qemu-server checks for "after-freeze" [1].
> 
> As a result, the post-unfreeze hook is never executed and the
> query-savevm polling loop intended to wait for savevm-end cleanup
> is skipped.

Applied, thanks! I modeled the test more closely after the actual
behavior, returning an empty JSON object after the savevm operation
has ended. This also required unsetting the savevm_ended property in
the test upon savevm-start. In a follow-up, I updated the existing
message in the loop to hopefully be a bit clearer to end-users.

[1/1] fix #7697: snapshot hook name mismatch
      commit: 568b295c7b425e16b8fd3f5b7fe1cfe7bcce94d9