From: Jamie Lokier <jamie@shareable.org>
To: Avi Kivity <avi@qumranet.com>
Cc: kvm-devel <kvm-devel@lists.sourceforge.net>,
Paul Brook <paul@codesourcery.com>,
qemu-devel@nongnu.org
Subject: Re: [kvm-devel] [Qemu-devel] Re: expose host CPU features to guests
Date: Sun, 9 Sep 2007 16:47:54 +0100 [thread overview]
Message-ID: <20070909154754.GC22349@mail.shareable.org> (raw)
In-Reply-To: <46E4114C.6090804@qumranet.com>
Avi Kivity wrote:
> >I agree. If the host OS has disabled a feature, it's a fair bet it's done
> >that for a reason.
>
> The reason may not be relevant to the guest.
For most guests the relevant features are those which work correctly
and efficiently on the virtual CPU.
If the host OS has disabled a feature, most often that's because the
feature doesn't work on the specific host CPU model, but not always.
It might be emulated well, but probably not efficiently.
In some cases, you might want a guest to see features supported by the
host CPU which the host OS has disabled, but I imagine those are
unusual - it doesn't seem very likely. Can you give an example?
They can be enabled explicitly by the -cpuid flag if needed.
-- Jamie
next prev parent reply other threads:[~2007-09-09 15:48 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-05 17:45 [Qemu-devel] expose host CPU features to guests danken
2007-09-05 19:26 ` [Qemu-devel] Re: [kvm-devel] " Anthony Liguori
2007-09-05 19:34 ` Avi Kivity
2007-09-05 19:44 ` Daniel P. Berrange
2007-09-06 0:30 ` Paul Brook
2007-09-06 8:46 ` Avi Kivity
2007-09-07 10:47 ` Jamie Lokier
2007-09-09 7:51 ` [kvm-devel] [Qemu-devel] " Avi Kivity
2007-09-09 12:47 ` Jamie Lokier
2007-09-09 12:55 ` Avi Kivity
2007-09-09 13:07 ` Jamie Lokier
2007-09-09 13:14 ` Avi Kivity
2007-09-09 15:25 ` Paul Brook
2007-09-09 15:29 ` Avi Kivity
2007-09-09 15:47 ` Jamie Lokier [this message]
2007-09-09 16:12 ` Paul Brook
2007-09-09 16:38 ` Avi Kivity
2007-09-10 16:53 ` Jamie Lokier
2007-09-10 7:40 ` [Qemu-devel] expose host CPU features to guests: Take 2 Dan Kenigsberg
2007-09-10 11:47 ` Natalia Portillo
2007-09-10 12:01 ` Dan Kenigsberg
2007-09-07 16:18 ` Natalia Portillo
2007-09-11 19:48 ` Luke -Jr
2007-09-10 17:16 ` Jamie Lokier
2007-09-24 17:41 ` [Qemu-devel] expose host CPU features to guests: Take 3 Dan Kenigsberg
2007-09-25 1:28 ` andrzej zaborowski
2007-09-25 8:48 ` [kvm-devel] " Dan Kenigsberg
2007-09-25 9:01 ` Avi Kivity
2007-09-25 9:19 ` J. Mayer
2007-09-25 9:31 ` Avi Kivity
2007-09-25 10:40 ` Avi Kivity
2007-09-25 11:09 ` J. Mayer
2007-09-25 11:36 ` Avi Kivity
2007-09-25 12:05 ` Fabrice Bellard
2007-09-25 13:07 ` Jocelyn Mayer
2007-09-25 13:12 ` Avi Kivity
2007-09-25 13:27 ` Dan Kenigsberg
2007-09-25 15:54 ` Jamie Lokier
2007-09-25 16:15 ` Avi Kivity
2007-09-25 12:51 ` Paul Brook
2007-09-25 13:13 ` Avi Kivity
2007-09-25 9:29 ` Fabrice Bellard
2007-10-07 12:38 ` [Qemu-devel] x86 -cpu option: Take 4 Dan Kenigsberg
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