Re: [PATCH V1 04/32] savevm: HMP Command for cprsave

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Steven Sistare <steven.sistare@oracle.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Juan Quintela" <quintela@redhat.com>,
	qemu-devel@nongnu.org, "Markus Armbruster" <armbru@redhat.com>,
	"Alex Williamson" <alex.williamson@redhat.com>,
	"Stefan Hajnoczi" <stefanha@redhat.com>,
	"Marc-André Lureau" <marcandre.lureau@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: Re: [PATCH V1 04/32] savevm: HMP Command for cprsave
Date: Fri, 25 Sep 2020 10:26:55 +0100	[thread overview]
Message-ID: <20200925092655.GF2873@work-vm> (raw)
In-Reply-To: <ae5bf659-c25e-8af4-ba14-a5a21476758f@oracle.com>

* Steven Sistare (steven.sistare@oracle.com) wrote:
> On 9/11/2020 12:57 PM, Dr. David Alan Gilbert wrote:
> > * Steve Sistare (steven.sistare@oracle.com) wrote:
> >> Enable HMP access to the cprsave QMP command.
> >>
> >> Usage: cprsave <filename> <mode>
> >>
> >> Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
> >> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> > 
> > I realise that the current mode is currently only 'reboot' - can you
> > please give us a clue as to why you've got a mode argument that's
> > currently only got one mode?
> 
> Patch 14 adds the restart mode.
> I factored the patches by capability to make the review easier, first
> presenting the reboot patches, then the restart patches.

OK, but just add a comment here saying that you'll add another mode
later; otherwise it looks a bit weird.

Dave

> - Steve
> 
> >> ---
> >>  hmp-commands.hx       | 18 ++++++++++++++++++
> >>  include/monitor/hmp.h |  1 +
> >>  monitor/hmp-cmds.c    | 10 ++++++++++
> >>  3 files changed, 29 insertions(+)
> >>
> >> diff --git a/hmp-commands.hx b/hmp-commands.hx
> >> index 60f395c..c8defd9 100644
> >> --- a/hmp-commands.hx
> >> +++ b/hmp-commands.hx
> >> @@ -354,6 +354,24 @@ SRST
> >>  ERST
> >>  
> >>      {
> >> +        .name       = "cprsave",
> >> +        .args_type  = "file:s,mode:s",
> >> +        .params     = "file 'reboot'",
> >> +        .help       = "create a checkpoint of the VM in file",
> >> +        .cmd        = hmp_cprsave,
> >> +    },
> >> +
> >> +SRST
> >> +``cprsave`` *tag*
> >> +  Stop VCPUs, create a checkpoint of the whole virtual machine and save it
> >> +  in *file*.
> >> +  If *mode* is 'reboot', the checkpoint can be cprload'ed after a host kexec
> >> +  reboot.
> >> +  exec() /usr/bin/qemu-exec if it exists, else exec /usr/bin/qemu-system-x86_64,
> >> +  passing all the original command line arguments.  The VCPUs remain paused.
> >> +ERST
> >> +
> >> +    {
> >>          .name       = "delvm",
> >>          .args_type  = "name:s",
> >>          .params     = "tag",
> >> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
> >> index c986cfd..af8ee23 100644
> >> --- a/include/monitor/hmp.h
> >> +++ b/include/monitor/hmp.h
> >> @@ -59,6 +59,7 @@ void hmp_balloon(Monitor *mon, const QDict *qdict);
> >>  void hmp_loadvm(Monitor *mon, const QDict *qdict);
> >>  void hmp_savevm(Monitor *mon, const QDict *qdict);
> >>  void hmp_delvm(Monitor *mon, const QDict *qdict);
> >> +void hmp_cprsave(Monitor *mon, const QDict *qdict);
> >>  void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
> >>  void hmp_migrate_continue(Monitor *mon, const QDict *qdict);
> >>  void hmp_migrate_incoming(Monitor *mon, const QDict *qdict);
> >> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> >> index ae4b6a4..59196ed 100644
> >> --- a/monitor/hmp-cmds.c
> >> +++ b/monitor/hmp-cmds.c
> >> @@ -1139,6 +1139,16 @@ void hmp_announce_self(Monitor *mon, const QDict *qdict)
> >>      qapi_free_AnnounceParameters(params);
> >>  }
> >>  
> >> +void hmp_cprsave(Monitor *mon, const QDict *qdict)
> >> +{
> >> +    Error *err = NULL;
> >> +
> >> +    qmp_cprsave(qdict_get_try_str(qdict, "file"),
> >> +                qdict_get_try_str(qdict, "mode"),
> >> +                &err);
> >> +    hmp_handle_error(mon, err);
> >> +}
> >> +
> >>  void hmp_migrate_cancel(Monitor *mon, const QDict *qdict)
> >>  {
> >>      qmp_migrate_cancel(NULL);
> >> -- 
> >> 1.8.3.1
> >>
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK