On Tue, Jul 16, 2024 at 10:27:29 +0200, Denis V. Lunev via Devel wrote:
> On 7/16/24 00:42, Nikolai Barybin wrote:
> > The usage of HMP commands are highly discouraged by qemu. Moreover,
> > current snapshot creation routine does not provide flexibility in
> > choosing target device for VM state snapshot.
> >
> > This patch makes use of QMP commands snapshot-save/delete and by
> > default chooses first writable disk (if present) as target for VM
> > state, NVRAM - otherwise.
> >
> > Signed-off-by: Nikolai Barybin <[email protected]>
> > ---
> > src/qemu/qemu_snapshot.c | 158 ++++++++++++++++++++++++++++++++++++---
> > 1 file changed, 148 insertions(+), 10 deletions(-)
[...]
> > @@ -342,15 +432,17 @@ qemuSnapshotCreateActiveInternal(virQEMUDriver
> > *driver,
> > }
> > }
> > - if (qemuDomainObjEnterMonitorAsync(vm, VIR_ASYNC_JOB_SNAPSHOT) < 0) {
> > + if ((ret = qemuSnapshotCreateActiveInternalStart(vm, snap->def->name))
> > < 0) {
> > resume = false;
> > goto cleanup;
> > }
> > - ret = qemuMonitorCreateSnapshot(priv->mon, snap->def->name);
> > - qemuDomainObjExitMonitor(vm);
> > - if (ret < 0)
> > - goto cleanup;
>
> 'snapshot-save' has been added in QEMU 6.0.
> Right now we are at 8.2
>
> Should we still support pre 6.0 versions, i.e. check the availability of the
> command via proper capability?
Libvirt currently supports qemu-5.2 as the oldest version, and since
that does not yet support the new commands we will need to use
capabilities and retain the old code.
This also means that patch 4/4 must be dropped as it's required for that
one release unfortunately.
qemu-5.2 seems to be currently the version in Debian 11 and openSUSE Leap 15.3
per commit 073bf167843ca2e788cbc581781c729ff26c80f5
which bumped it recently
