From: Avi Kivity <avi@redhat.com>
To: Jason <kvmuser@gmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: [Qemu-devel] Ideas wiki for GSoC 2010
Date: Tue, 16 Mar 2010 08:12:00 +0200 [thread overview]
Message-ID: <4B9F2130.6030903@redhat.com> (raw)
In-Reply-To: <loom.20100316T004722-518@post.gmane.org>
On 03/16/2010 02:20 AM, Jason wrote:
>
> In comparing KVM 2.6.31.6b to XenServer 5.5.0, it seems KVM has fewer overall
> VMREADs and VMWRITEs, but there are a lot of VMWRITEs to Host FS_SEL, Host
> GS_SEL, Host FS_BASE, and Host GS_BASE that don't appear in Xen.
Ugh, these should definitely be eliminated, they keep writing the same
value most of the time.
> Also, KVM has a
> lot of MSR accesses to 0xc0000081-0xc0000084 that Xen doesn't have.
>
These are unavoidable. Those msrs are used for system calls and we need
them to keep ordinary userspace going.
2.6.33 should reduce their frequency though.
Usually it doesn't make sense to pass them through, but if we detect the
guest is writing them often, we can do so and eliminate the exits.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
next prev parent reply other threads:[~2010-03-16 6:12 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-10 21:30 Ideas wiki for GSoC 2010 Luiz Capitulino
2010-03-11 7:55 ` Avi Kivity
2010-03-11 9:43 ` Paolo Bonzini
2010-03-11 11:25 ` Alexander Graf
2010-03-11 11:54 ` Avi Kivity
2010-03-11 11:56 ` Alexander Graf
2010-03-11 11:58 ` Avi Kivity
2010-03-11 12:03 ` Alexander Graf
2010-03-11 12:15 ` Avi Kivity
2010-03-12 10:49 ` [Android-virt] " Christoffer Dall
2010-03-12 12:32 ` Luiz Capitulino
2010-03-11 19:06 ` [Qemu-devel] " Cam Macdonell
2010-03-11 12:09 ` Paolo Bonzini
2010-03-11 13:19 ` Luiz Capitulino
2010-03-13 3:13 ` [Qemu-devel] " Edgar E. Iglesias
2010-03-11 13:16 ` Luiz Capitulino
2010-03-12 10:47 ` [Qemu-devel] " Jes Sorensen
2010-03-11 12:59 ` Luiz Capitulino
2010-03-11 13:00 ` Alexander Graf
2010-03-11 13:21 ` Luiz Capitulino
2010-03-11 22:59 ` [Qemu-devel] " Jamie Lokier
2010-03-12 9:48 ` Paolo Bonzini
2010-03-12 9:59 ` Gleb Natapov
2010-03-11 12:26 ` Avi Kivity
2010-03-11 13:09 ` [Qemu-devel] " Lucas Meneghel Rodrigues
2010-03-12 15:11 ` Adam Litke
2010-03-12 15:22 ` Luiz Capitulino
2010-03-12 15:38 ` Adam Litke
2010-03-12 15:56 ` Luiz Capitulino
2010-03-12 16:36 ` Anthony Liguori
2010-03-12 17:35 ` Luiz Capitulino
2010-03-15 12:25 ` Avi Kivity
2010-03-15 12:38 ` Joerg Roedel
2010-03-15 12:42 ` Avi Kivity
2010-03-15 13:14 ` Anthony Liguori
2010-03-15 15:59 ` Joerg Roedel
2010-03-15 12:53 ` Muli Ben-Yehuda
2010-03-15 13:03 ` Joerg Roedel
2010-03-15 13:11 ` Avi Kivity
2010-03-15 13:23 ` Anthony Liguori
2010-03-15 15:06 ` Avi Kivity
2010-03-16 0:20 ` Jason
2010-03-16 6:12 ` Avi Kivity [this message]
2010-03-16 16:33 ` Jason
2010-03-16 16:46 ` Avi Kivity
2010-03-16 1:21 ` Anthony Liguori
2010-03-16 5:50 ` Avi Kivity
2010-03-15 13:24 ` Joerg Roedel
2010-03-15 13:55 ` Anthony Liguori
2010-03-15 14:18 ` Muli Ben-Yehuda
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