From: Paolo Bonzini <pbonzini@redhat.com>
To: Glauber Costa <glommer@redhat.com>
Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, avi@redhat.com,
mtosatti@redhat.com
Subject: Re: [PATCH v2 0/2] savevm odness related to kvmclock
Date: Mon, 06 Dec 2010 15:10:36 +0100 [thread overview]
Message-ID: <4CFCEEDC.6040009@redhat.com> (raw)
In-Reply-To: <1291644227-22923-1-git-send-email-glommer@redhat.com>
On 12/06/2010 03:03 PM, Glauber Costa wrote:
> Some users told me that savevm path is behaving oddly wrt kvmclock.
> The first oddness is that a guarantee we never made (AFAIK) is being broken:
> two consecutive "savevm" operations, with the machine stopped in between
> produces different results, due to the call to KVM_GET_CLOCK ioctl.
> I believe the assumption that if the vm does not run, its saveable
> state won't change is fairly reasonable. Maybe we should formally
> guarantee that?
>
> Also, this patch deals with the fact that this happens even if
> kvmclock is disabled in cpuid: its savevm section is registered
> nevertheless. Here, I try to register it only if it's enabled at
> machine start.
>
> v2: improvements suggested by Paolo, and patch reordering.
>
> Glauber Costa (2):
> Do not register kvmclock savevm section if kvmclock is disabled.
> make kvmclock value idempotent for stopped machine
>
> cpus.c | 3 +++
> qemu-kvm-x86.c | 23 +++++++++++++++--------
> qemu-kvm.h | 3 +++
> target-i386/kvm.c | 7 +++++++
> 4 files changed, 28 insertions(+), 8 deletions(-)
ACK
Paolo
WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: Glauber Costa <glommer@redhat.com>
Cc: mtosatti@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org,
avi@redhat.com
Subject: [Qemu-devel] Re: [PATCH v2 0/2] savevm odness related to kvmclock
Date: Mon, 06 Dec 2010 15:10:36 +0100 [thread overview]
Message-ID: <4CFCEEDC.6040009@redhat.com> (raw)
In-Reply-To: <1291644227-22923-1-git-send-email-glommer@redhat.com>
On 12/06/2010 03:03 PM, Glauber Costa wrote:
> Some users told me that savevm path is behaving oddly wrt kvmclock.
> The first oddness is that a guarantee we never made (AFAIK) is being broken:
> two consecutive "savevm" operations, with the machine stopped in between
> produces different results, due to the call to KVM_GET_CLOCK ioctl.
> I believe the assumption that if the vm does not run, its saveable
> state won't change is fairly reasonable. Maybe we should formally
> guarantee that?
>
> Also, this patch deals with the fact that this happens even if
> kvmclock is disabled in cpuid: its savevm section is registered
> nevertheless. Here, I try to register it only if it's enabled at
> machine start.
>
> v2: improvements suggested by Paolo, and patch reordering.
>
> Glauber Costa (2):
> Do not register kvmclock savevm section if kvmclock is disabled.
> make kvmclock value idempotent for stopped machine
>
> cpus.c | 3 +++
> qemu-kvm-x86.c | 23 +++++++++++++++--------
> qemu-kvm.h | 3 +++
> target-i386/kvm.c | 7 +++++++
> 4 files changed, 28 insertions(+), 8 deletions(-)
ACK
Paolo
next prev parent reply other threads:[~2010-12-06 14:10 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-06 14:03 [PATCH v2 0/2] savevm odness related to kvmclock Glauber Costa
2010-12-06 14:03 ` [Qemu-devel] " Glauber Costa
2010-12-06 14:03 ` [PATCH v2 1/2] Do not register kvmclock savevm section if kvmclock is disabled Glauber Costa
2010-12-06 14:03 ` [Qemu-devel] " Glauber Costa
2010-12-06 21:04 ` Marcelo Tosatti
2010-12-06 21:04 ` [Qemu-devel] " Marcelo Tosatti
2010-12-06 21:55 ` Marcelo Tosatti
2010-12-06 21:55 ` [Qemu-devel] " Marcelo Tosatti
2010-12-07 17:12 ` Glauber Costa
2010-12-07 17:12 ` [Qemu-devel] " Glauber Costa
2010-12-08 19:31 ` Marcelo Tosatti
2010-12-08 19:31 ` [Qemu-devel] " Marcelo Tosatti
2010-12-13 13:40 ` Glauber Costa
2010-12-13 13:40 ` [Qemu-devel] " Glauber Costa
2010-12-06 14:03 ` [PATCH v2 2/2] make kvmclock value idempotent for stopped machine Glauber Costa
2010-12-06 14:03 ` [Qemu-devel] " Glauber Costa
2010-12-06 14:10 ` Paolo Bonzini [this message]
2010-12-06 14:10 ` [Qemu-devel] Re: [PATCH v2 0/2] savevm odness related to kvmclock Paolo Bonzini
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