From: "Michael S. Tsirkin" <mst@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: qemu-devel@nongnu.org, avi@redhat.com
Subject: Re: [Qemu-devel] cpuid problem in upstream qemu with kvm
Date: Mon, 14 Dec 2009 22:14:09 +0200 [thread overview]
Message-ID: <20091214201409.GE6150@redhat.com> (raw)
In-Reply-To: <20091214200838.GB27769@redhat.com>
On Mon, Dec 14, 2009 at 10:08:38PM +0200, Gleb Natapov wrote:
> On Mon, Dec 14, 2009 at 02:02:03PM -0600, Anthony Liguori wrote:
> > Gleb Natapov wrote:
> > >>I thought KVM emulates the syscall instruction? I swear I've seen
> > >>patches for that.
> > >>
> > >It is. Starting from 2.6.32.
> >
> > Okay, so this is a performance vs. migration compatibility issue then?
> >
> > BTW, couldn't we just not advertise syscall in cpuid? That should
> > fix it too without sacrificing migration compatibility. We get a
> > slight slowdown on AMD hosts but that's probably minor compared to
> > the cost of using emulated syscall on Intel hosts.
> >
> As far as I understand not advertising syscall for 64bit CPU is not a
> valid option.
Yes. 64 bit kernel 32 bit userpace crashes with -cpu qemu64,-syscall.
> --
> Gleb.
next prev parent reply other threads:[~2009-12-14 20:17 UTC|newest]
Thread overview: 113+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-14 19:35 [Qemu-devel] cpuid problem in upstream qemu with kvm Michael S. Tsirkin
2009-12-14 19:44 ` Anthony Liguori
2009-12-14 19:44 ` Michael S. Tsirkin
2009-12-14 19:57 ` Anthony Liguori
2009-12-14 20:00 ` Gleb Natapov
2009-12-14 20:02 ` Anthony Liguori
2009-12-14 20:08 ` Gleb Natapov
2009-12-14 20:14 ` Michael S. Tsirkin [this message]
2009-12-14 20:10 ` Michael S. Tsirkin
2009-12-14 20:18 ` Anthony Liguori
2009-12-14 20:31 ` Michael S. Tsirkin
2009-12-14 20:54 ` Anthony Liguori
2009-12-14 21:10 ` Michael S. Tsirkin
2009-12-14 21:49 ` Anthony Liguori
2009-12-15 14:28 ` Michael S. Tsirkin
2009-12-15 17:37 ` Anthony Liguori
2009-12-15 17:56 ` Michael S. Tsirkin
2009-12-20 9:42 ` Avi Kivity
2009-12-20 9:49 ` Avi Kivity
2009-12-20 14:48 ` Anthony Liguori
2009-12-20 14:55 ` Avi Kivity
2009-12-20 15:33 ` Anthony Liguori
2009-12-20 15:36 ` Avi Kivity
2009-12-20 15:38 ` Gleb Natapov
2009-12-20 15:40 ` Avi Kivity
2009-12-20 15:49 ` Michael S. Tsirkin
2009-12-20 15:53 ` Avi Kivity
2009-12-20 15:51 ` Michael S. Tsirkin
2009-12-20 15:59 ` Avi Kivity
2009-12-20 16:56 ` Michael S. Tsirkin
2009-12-20 17:17 ` Alexander Graf
2009-12-20 17:18 ` Michael S. Tsirkin
2009-12-20 17:23 ` Alexander Graf
2009-12-20 17:23 ` Gleb Natapov
2009-12-20 17:29 ` Alexander Graf
2009-12-20 17:37 ` Gleb Natapov
2009-12-20 17:59 ` Anthony Liguori
2009-12-20 18:06 ` Alexander Graf
2009-12-21 7:48 ` Gleb Natapov
2009-12-21 13:25 ` [Qemu-devel] " Paolo Bonzini
2009-12-20 18:12 ` [Qemu-devel] " Michael S. Tsirkin
2009-12-21 7:43 ` Gleb Natapov
2009-12-21 8:28 ` Dor Laor
2009-12-21 22:51 ` john cooper
2009-12-22 13:54 ` Dor Laor
2009-12-22 15:19 ` john cooper
2009-12-22 16:12 ` Anthony Liguori
2010-01-05 6:06 ` john cooper
2010-01-06 8:02 ` [Qemu-devel] " Paolo Bonzini
[not found] ` <4B31F1BA.10005@redhat.com>
2010-01-06 0:10 ` [Qemu-devel] " Anthony Liguori
2010-01-06 3:25 ` Avi Kivity
2010-01-06 13:25 ` Anthony Liguori
2010-01-06 13:35 ` Michael S. Tsirkin
2010-01-06 13:47 ` Avi Kivity
2010-01-06 13:49 ` Anthony Liguori
2010-01-06 13:54 ` Avi Kivity
2010-01-06 13:55 ` Alexander Graf
2010-01-06 13:58 ` Avi Kivity
2010-01-06 14:22 ` Michael S. Tsirkin
2010-01-06 14:32 ` Avi Kivity
2010-01-06 14:48 ` Dor Laor
2010-01-06 15:16 ` Anthony Liguori
2010-01-07 8:03 ` Dor Laor
2010-01-07 8:18 ` Avi Kivity
2010-01-07 9:11 ` Dor Laor
2010-01-07 9:24 ` Avi Kivity
2010-01-07 9:40 ` Dor Laor
2010-01-07 11:39 ` Anthony Liguori
2010-01-07 11:44 ` Dor Laor
2010-01-07 12:00 ` Avi Kivity
2010-01-07 12:20 ` Dor Laor
2010-01-07 12:33 ` Anthony Liguori
2010-01-07 12:40 ` Avi Kivity
2010-01-07 12:47 ` Daniel P. Berrange
2010-01-07 12:50 ` Avi Kivity
2010-01-07 13:14 ` Anthony Liguori
2010-01-07 13:42 ` Dor Laor
2010-01-11 13:26 ` Markus Armbruster
2010-01-07 11:59 ` Avi Kivity
2010-01-07 12:17 ` Dor Laor
2010-01-07 8:24 ` Daniel P. Berrange
2010-01-07 9:13 ` Dor Laor
2010-01-06 15:02 ` Michael S. Tsirkin
2010-01-06 15:12 ` Anthony Liguori
2010-01-06 9:44 ` Daniel P. Berrange
2010-01-06 9:54 ` Avi Kivity
2010-01-06 10:21 ` Daniel P. Berrange
2010-01-06 10:25 ` Avi Kivity
2010-01-06 16:19 ` Lennart Sorensen
2009-12-21 11:15 ` Avi Kivity
2009-12-21 12:59 ` Andre Przywara
2009-12-21 16:14 ` Avi Kivity
2009-12-22 23:02 ` Jamie Lokier
2009-12-21 11:12 ` Avi Kivity
2009-12-21 11:18 ` Michael S. Tsirkin
2009-12-21 11:22 ` Alexander Graf
2009-12-21 11:38 ` Michael S. Tsirkin
2009-12-21 11:45 ` Alexander Graf
2009-12-21 12:02 ` Michael S. Tsirkin
2009-12-22 22:52 ` Jamie Lokier
2009-12-21 12:05 ` Avi Kivity
2009-12-21 13:45 ` David S. Ahern
2009-12-21 13:51 ` Michael S. Tsirkin
2009-12-21 14:07 ` David S. Ahern
2009-12-21 16:11 ` Avi Kivity
2009-12-21 12:04 ` Avi Kivity
2009-12-21 12:04 ` Michael S. Tsirkin
2009-12-21 12:09 ` Avi Kivity
2009-12-21 12:17 ` Michael S. Tsirkin
2009-12-21 11:38 ` Yaniv Kaul
2009-12-21 13:31 ` [Qemu-devel] " Paolo Bonzini
2009-12-22 22:56 ` Jamie Lokier
2009-12-16 14:23 ` [Qemu-devel] " Andre Przywara
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20091214201409.GE6150@redhat.com \
--to=mst@redhat.com \
--cc=avi@redhat.com \
--cc=gleb@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).