* Re: [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure
2021-05-11 16:31 [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure Kevin Wolf
@ 2021-05-11 16:49 ` Daniel P. Berrangé
2021-05-11 16:58 ` Kevin Wolf
2021-05-12 19:16 ` Dr. David Alan Gilbert
2021-05-25 17:43 ` Dr. David Alan Gilbert
2 siblings, 1 reply; 6+ messages in thread
From: Daniel P. Berrangé @ 2021-05-11 16:49 UTC (permalink / raw)
To: Kevin Wolf; +Cc: qemu-stable, yama, dgilbert, qemu-block, qemu-devel
On Tue, May 11, 2021 at 06:31:51PM +0200, Kevin Wolf wrote:
> Commit f61fe11aa6f broke hmp_loadvm() by adding an incorrect negation
> when converting from 0/-errno return values to a bool value. The result
> is that loadvm resumes the VM now if it failed and keeps it stopped if
> it failed. Fix it to restore the old behaviour and do it the other way
> around.
>
> Fixes: f61fe11aa6f7f8f0ffe4ddaa56a8108f3ab57854
> Cc: qemu-stable@nongnu.org
> Reported-by: Yanhui Ma <yama@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
> monitor/hmp-cmds.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 0ad5b77477..cc15d9b6ee 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -1133,7 +1133,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
>
> vm_stop(RUN_STATE_RESTORE_VM);
>
> - if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> + if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> vm_start();
> }
> hmp_handle_error(mon, err);
Paolo had sent a different fix here:
https://lists.gnu.org/archive/html/qemu-devel/2021-05/msg01093.html
As with my feedback there, I think we should be adding test coverage
when fixing this. How about this:
diff --git a/tests/qemu-iotests/068 b/tests/qemu-iotests/068
index 54e49c8ffa..137c5d0577 100755
--- a/tests/qemu-iotests/068
+++ b/tests/qemu-iotests/068
@@ -77,7 +77,7 @@ for extra_args in \
# Give qemu some time to boot before saving the VM state
{ sleep 1; printf "savevm 0\nquit\n"; } | _qemu $extra_args
# Now try to continue from that VM state (this should just work)
- { sleep 1; printf "loadvm 0\nloadvm 0\nquit\n"; } | _qemu $extra_args -S
+ { sleep 1; printf "info status\nloadvm 0\ninfo status\ncont\ninfo status\nloadvm 0\ninfo status\nquit\n"; } | _qemu $extra_args -S
done
# success, all done
diff --git a/tests/qemu-iotests/068.out b/tests/qemu-iotests/068.out
index f07a938a38..75c0a5df5f 100644
--- a/tests/qemu-iotests/068.out
+++ b/tests/qemu-iotests/068.out
@@ -7,8 +7,17 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm 0
(qemu) quit
QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) info status
+VM status: paused (prelaunch)
(qemu) loadvm 0
+(qemu) info status
+VM status: paused (prelaunch)
+(qemu) cont
+(qemu) info status
+VM status: running
(qemu) loadvm 0
+(qemu) info status
+VM status: running
(qemu) quit
=== Saving and reloading a VM state to/from a qcow2 image (-object iothread,id=iothread0 -set device.hba0.iothread=iothread0) ===
@@ -18,7 +27,16 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm 0
(qemu) quit
QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) info status
+VM status: paused (prelaunch)
(qemu) loadvm 0
+(qemu) info status
+VM status: paused (prelaunch)
+(qemu) cont
+(qemu) info status
+VM status: running
(qemu) loadvm 0
+(qemu) info status
+VM status: running
(qemu) quit
*** done
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure
2021-05-11 16:49 ` Daniel P. Berrangé
@ 2021-05-11 16:58 ` Kevin Wolf
2021-05-11 17:05 ` Daniel P. Berrangé
0 siblings, 1 reply; 6+ messages in thread
From: Kevin Wolf @ 2021-05-11 16:58 UTC (permalink / raw)
To: Daniel P. Berrangé
Cc: qemu-stable, yama, dgilbert, qemu-block, qemu-devel
Am 11.05.2021 um 18:49 hat Daniel P. Berrangé geschrieben:
> On Tue, May 11, 2021 at 06:31:51PM +0200, Kevin Wolf wrote:
> > Commit f61fe11aa6f broke hmp_loadvm() by adding an incorrect negation
> > when converting from 0/-errno return values to a bool value. The result
> > is that loadvm resumes the VM now if it failed and keeps it stopped if
> > it failed. Fix it to restore the old behaviour and do it the other way
> > around.
> >
> > Fixes: f61fe11aa6f7f8f0ffe4ddaa56a8108f3ab57854
> > Cc: qemu-stable@nongnu.org
> > Reported-by: Yanhui Ma <yama@redhat.com>
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> > monitor/hmp-cmds.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> > index 0ad5b77477..cc15d9b6ee 100644
> > --- a/monitor/hmp-cmds.c
> > +++ b/monitor/hmp-cmds.c
> > @@ -1133,7 +1133,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
> >
> > vm_stop(RUN_STATE_RESTORE_VM);
> >
> > - if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> > + if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> > vm_start();
> > }
> > hmp_handle_error(mon, err);
>
> Paolo had sent a different fix here:
>
> https://lists.gnu.org/archive/html/qemu-devel/2021-05/msg01093.html
Hm... I missed that patch, but doesn't it just generalise the buggy HMP
code instead of fixing it? That is, we still resume the VM on failure
rather than on success?
> As with my feedback there, I think we should be adding test coverage
> when fixing this. How about this:
> [...]
Yes, this looks good.
Kevin
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure
2021-05-11 16:58 ` Kevin Wolf
@ 2021-05-11 17:05 ` Daniel P. Berrangé
0 siblings, 0 replies; 6+ messages in thread
From: Daniel P. Berrangé @ 2021-05-11 17:05 UTC (permalink / raw)
To: Kevin Wolf; +Cc: qemu-stable, yama, dgilbert, qemu-block, qemu-devel
On Tue, May 11, 2021 at 06:58:01PM +0200, Kevin Wolf wrote:
> Am 11.05.2021 um 18:49 hat Daniel P. Berrangé geschrieben:
> > On Tue, May 11, 2021 at 06:31:51PM +0200, Kevin Wolf wrote:
> > > Commit f61fe11aa6f broke hmp_loadvm() by adding an incorrect negation
> > > when converting from 0/-errno return values to a bool value. The result
> > > is that loadvm resumes the VM now if it failed and keeps it stopped if
> > > it failed. Fix it to restore the old behaviour and do it the other way
> > > around.
> > >
> > > Fixes: f61fe11aa6f7f8f0ffe4ddaa56a8108f3ab57854
> > > Cc: qemu-stable@nongnu.org
> > > Reported-by: Yanhui Ma <yama@redhat.com>
> > > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > > ---
> > > monitor/hmp-cmds.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> > > index 0ad5b77477..cc15d9b6ee 100644
> > > --- a/monitor/hmp-cmds.c
> > > +++ b/monitor/hmp-cmds.c
> > > @@ -1133,7 +1133,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
> > >
> > > vm_stop(RUN_STATE_RESTORE_VM);
> > >
> > > - if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> > > + if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> > > vm_start();
> > > }
> > > hmp_handle_error(mon, err);
> >
> > Paolo had sent a different fix here:
> >
> > https://lists.gnu.org/archive/html/qemu-devel/2021-05/msg01093.html
>
> Hm... I missed that patch, but doesn't it just generalise the buggy HMP
> code instead of fixing it? That is, we still resume the VM on failure
> rather than on success?
Yes, if I use my iotest patch on Paolo's patch it shows that it is
still broken.
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure
2021-05-11 16:31 [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure Kevin Wolf
2021-05-11 16:49 ` Daniel P. Berrangé
@ 2021-05-12 19:16 ` Dr. David Alan Gilbert
2021-05-25 17:43 ` Dr. David Alan Gilbert
2 siblings, 0 replies; 6+ messages in thread
From: Dr. David Alan Gilbert @ 2021-05-12 19:16 UTC (permalink / raw)
To: Kevin Wolf; +Cc: qemu-stable, berrange, yama, qemu-block, qemu-devel
* Kevin Wolf (kwolf@redhat.com) wrote:
> Commit f61fe11aa6f broke hmp_loadvm() by adding an incorrect negation
> when converting from 0/-errno return values to a bool value. The result
> is that loadvm resumes the VM now if it failed and keeps it stopped if
> it failed. Fix it to restore the old behaviour and do it the other way
> around.
I think your wording is wrong there - you have two 'if it failed'
> Fixes: f61fe11aa6f7f8f0ffe4ddaa56a8108f3ab57854
> Cc: qemu-stable@nongnu.org
> Reported-by: Yanhui Ma <yama@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
> monitor/hmp-cmds.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 0ad5b77477..cc15d9b6ee 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -1133,7 +1133,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
>
> vm_stop(RUN_STATE_RESTORE_VM);
>
> - if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> + if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> vm_start();
So if I'm reading htat right, that gets you it restarting it if
load_snapshot returns true, and it returns true if the load_snapshot
worked; i.e. if we were running and we succesfully load a snasphot
then we carry on running.
Other than the commit message, it makes sense tome:
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> }
> hmp_handle_error(mon, err);
> --
> 2.30.2
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure
2021-05-11 16:31 [PATCH] hmp: Fix loadvm to resume the VM on success instead of failure Kevin Wolf
2021-05-11 16:49 ` Daniel P. Berrangé
2021-05-12 19:16 ` Dr. David Alan Gilbert
@ 2021-05-25 17:43 ` Dr. David Alan Gilbert
2 siblings, 0 replies; 6+ messages in thread
From: Dr. David Alan Gilbert @ 2021-05-25 17:43 UTC (permalink / raw)
To: Kevin Wolf; +Cc: qemu-stable, berrange, yama, qemu-block, qemu-devel
* Kevin Wolf (kwolf@redhat.com) wrote:
> Commit f61fe11aa6f broke hmp_loadvm() by adding an incorrect negation
> when converting from 0/-errno return values to a bool value. The result
> is that loadvm resumes the VM now if it failed and keeps it stopped if
> it failed. Fix it to restore the old behaviour and do it the other way
> around.
>
> Fixes: f61fe11aa6f7f8f0ffe4ddaa56a8108f3ab57854
> Cc: qemu-stable@nongnu.org
> Reported-by: Yanhui Ma <yama@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
queued
> ---
> monitor/hmp-cmds.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 0ad5b77477..cc15d9b6ee 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -1133,7 +1133,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
>
> vm_stop(RUN_STATE_RESTORE_VM);
>
> - if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> + if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
> vm_start();
> }
> hmp_handle_error(mon, err);
> --
> 2.30.2
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 6+ messages in thread