From: "Michael S. Tsirkin" <mst@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
Anthony Liguori <anthony@codemonkey.ws>,
avi@redhat.com, gleb@redhat.com, qemu-devel@nongnu.org,
kvm@vger.kernel.org, Jan Kiszka <jan.kiszka@web.de>,
Blue Swirl <blauwirbel@gmail.com>
Subject: Re: [Qemu-devel] [PATCHv4 3/4] cpuid: disable pv eoi for 1.1 and older compat types
Date: Wed, 29 Aug 2012 13:32:26 +0300 [thread overview]
Message-ID: <20120829103226.GE5225@redhat.com> (raw)
In-Reply-To: <20120829100334.GB561@amt.cnet>
On Wed, Aug 29, 2012 at 07:03:34AM -0300, Marcelo Tosatti wrote:
> On Wed, Aug 29, 2012 at 06:59:03AM -0300, Marcelo Tosatti wrote:
> > > I don't understand. What is the problem with the proposal?
> > > What will not work with our protocol?
> > > Can you give an example please?
> > >
> > >
> > > > > Too late for 1.2?
> > > >
> > > > Absolutely (in my opinion).
> >
> > My concern here is that you are introducing infrastructure by using
> > _one example_, claiming it to solve a general problem, without the
> > appropriate amount of energy spent in this solution.
> >
> > Using old machines is supposed to be supported on older guests.
> >
> > Michael, not migrating the PVEOI MSR actually crashes the guest?
>
> Which is irrelevant since it won't be able to migrate to an older
> qemu.
>
With this patch, -M pc-1.1 migrates fine to an older qemu
and no crash.
Without, PV EOI bit in CPUID is set on source so
we have a problem.
--
MST
WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: gleb@redhat.com, kvm@vger.kernel.org, qemu-devel@nongnu.org,
Blue Swirl <blauwirbel@gmail.com>, Jan Kiszka <jan.kiszka@web.de>,
avi@redhat.com, Anthony Liguori <anthony@codemonkey.ws>,
Eduardo Habkost <ehabkost@redhat.com>
Subject: Re: [Qemu-devel] [PATCHv4 3/4] cpuid: disable pv eoi for 1.1 and older compat types
Date: Wed, 29 Aug 2012 13:32:26 +0300 [thread overview]
Message-ID: <20120829103226.GE5225@redhat.com> (raw)
In-Reply-To: <20120829100334.GB561@amt.cnet>
On Wed, Aug 29, 2012 at 07:03:34AM -0300, Marcelo Tosatti wrote:
> On Wed, Aug 29, 2012 at 06:59:03AM -0300, Marcelo Tosatti wrote:
> > > I don't understand. What is the problem with the proposal?
> > > What will not work with our protocol?
> > > Can you give an example please?
> > >
> > >
> > > > > Too late for 1.2?
> > > >
> > > > Absolutely (in my opinion).
> >
> > My concern here is that you are introducing infrastructure by using
> > _one example_, claiming it to solve a general problem, without the
> > appropriate amount of energy spent in this solution.
> >
> > Using old machines is supposed to be supported on older guests.
> >
> > Michael, not migrating the PVEOI MSR actually crashes the guest?
>
> Which is irrelevant since it won't be able to migrate to an older
> qemu.
>
With this patch, -M pc-1.1 migrates fine to an older qemu
and no crash.
Without, PV EOI bit in CPUID is set on source so
we have a problem.
--
MST
next prev parent reply other threads:[~2012-08-29 10:31 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-28 17:43 [PATCHv4 0/4] migrate PV EOI MSR Michael S. Tsirkin
2012-08-28 17:43 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-28 17:43 ` [PATCHv4 1/4] linux-headers: update to 3.6-rc3 Michael S. Tsirkin
2012-08-28 17:43 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-28 17:43 ` [PATCHv4 2/4] pc: refactor compat code Michael S. Tsirkin
2012-08-28 17:43 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-29 14:49 ` Anthony Liguori
2012-08-29 14:49 ` [Qemu-devel] " Anthony Liguori
2012-08-28 17:43 ` [PATCHv4 3/4] cpuid: disable pv eoi for 1.1 and older compat types Michael S. Tsirkin
2012-08-28 17:43 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-28 19:13 ` Eduardo Habkost
2012-08-28 19:13 ` Eduardo Habkost
2012-08-28 21:35 ` Michael S. Tsirkin
2012-08-28 21:35 ` Michael S. Tsirkin
2012-08-28 22:02 ` Eduardo Habkost
2012-08-28 22:02 ` Eduardo Habkost
2012-08-28 22:21 ` Michael S. Tsirkin
2012-08-28 22:21 ` Michael S. Tsirkin
2012-08-28 22:25 ` Michael S. Tsirkin
2012-08-28 22:25 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-28 23:50 ` Eduardo Habkost
2012-08-28 23:50 ` Eduardo Habkost
2012-08-29 10:06 ` Michael S. Tsirkin
2012-08-29 10:06 ` Michael S. Tsirkin
2012-08-29 12:56 ` Eduardo Habkost
2012-08-29 12:56 ` Eduardo Habkost
2012-08-29 13:18 ` Michael S. Tsirkin
2012-08-29 13:18 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-29 13:49 ` Eduardo Habkost
2012-08-29 13:49 ` Eduardo Habkost
2012-08-29 14:11 ` Michael S. Tsirkin
2012-08-29 14:11 ` Michael S. Tsirkin
2012-08-29 14:21 ` Eduardo Habkost
2012-08-29 14:21 ` Eduardo Habkost
2012-08-29 9:59 ` Marcelo Tosatti
2012-08-29 9:59 ` Marcelo Tosatti
2012-08-29 10:03 ` Marcelo Tosatti
2012-08-29 10:03 ` Marcelo Tosatti
2012-08-29 10:32 ` Michael S. Tsirkin [this message]
2012-08-29 10:32 ` Michael S. Tsirkin
2012-08-29 10:23 ` Michael S. Tsirkin
2012-08-29 10:23 ` Michael S. Tsirkin
2012-08-29 10:31 ` Michael S. Tsirkin
2012-08-29 10:31 ` Michael S. Tsirkin
2012-08-29 14:43 ` Juan Quintela
2012-08-29 14:43 ` [Qemu-devel] " Juan Quintela
2012-08-29 13:36 ` Anthony Liguori
2012-08-29 13:36 ` [Qemu-devel] " Anthony Liguori
2012-08-29 13:40 ` Gleb Natapov
2012-08-29 13:40 ` [Qemu-devel] " Gleb Natapov
2012-08-29 14:09 ` Anthony Liguori
2012-08-29 14:09 ` [Qemu-devel] " Anthony Liguori
2012-08-29 14:29 ` Michael S. Tsirkin
2012-08-29 14:29 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-29 14:41 ` Eduardo Habkost
2012-08-29 15:04 ` [QEMU 1.2 PATCH] i386: kvm: have a predefined set of default KVM feature bits Eduardo Habkost
2012-08-29 15:04 ` [Qemu-devel] " Eduardo Habkost
2012-08-29 15:10 ` Michael S. Tsirkin
2012-08-29 15:10 ` [Qemu-devel] " Michael S. Tsirkin
2012-08-29 15:46 ` Marcelo Tosatti
2012-08-29 15:46 ` [Qemu-devel] " Marcelo Tosatti
2012-08-29 14:03 ` [Qemu-devel] [PATCHv4 3/4] cpuid: disable pv eoi for 1.1 and older compat types Eduardo Habkost
2012-08-29 14:03 ` Eduardo Habkost
2012-08-28 17:43 ` [PATCHv4 4/4] kvm: get/set PV EOI MSR Michael S. Tsirkin
2012-08-28 17:43 ` [Qemu-devel] " Michael S. Tsirkin
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