From: Anthony Liguori <anthony@codemonkey.ws>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: akataria@vmware.com, "avi@redhat.com" <avi@redhat.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Gerd Hoffmann <kraxel@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
the arch/x86 maintainers <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"Nakajima, Jun" <jun.nakajima@intel.com>,
Daniel Hecht <dhecht@vmware.com>, Zach Amsden <zach@vmware.com>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [RFC] CPUID usage for interaction between Hypervisors and Linux.
Date: Wed, 01 Oct 2008 16:34:09 -0500 [thread overview]
Message-ID: <48E3ECD1.30809@codemonkey.ws> (raw)
In-Reply-To: <48E3E8DE.1080602@goop.org>
Jeremy Fitzhardinge wrote:
> Alok Kataria wrote:
>
> I guess, but the bulk of the uses of this stuff are going to be
> hypervisor-specific. You're hard-pressed to come up with any other
> generic uses beyond tsc.
And arguably, storing TSC frequency in CPUID is a terrible interface
because the TSC frequency can change any time a guest is entered. It
really should be a shared memory area so that a guest doesn't have to
vmexit to read it (like it is with the Xen/KVM paravirt clock).
Regards,
Anthony Liguori
> In general, if a hypervisor is going to put something in a special
> cpuid leaf, its because there's no other good way to represent it.
> Generic things are generally going to appear as an emulated piece of
> the virtualized platform, in ACPI, DMI, a hardware-defined cpuid leaf,
> etc...
next prev parent reply other threads:[~2008-10-01 21:35 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-01 17:14 [RFC] CPUID usage for interaction between Hypervisors and Linux Alok Kataria
2008-10-01 17:21 ` H. Peter Anvin
2008-10-01 17:33 ` Alok Kataria
2008-10-01 17:45 ` H. Peter Anvin
2008-10-01 18:06 ` Jeremy Fitzhardinge
2008-10-01 21:05 ` Alok Kataria
2008-10-01 22:46 ` H. Peter Anvin
2008-10-02 1:11 ` Nakajima, Jun
2008-10-02 1:24 ` H. Peter Anvin
2008-10-03 22:33 ` Nakajima, Jun
2008-10-03 23:30 ` H. Peter Anvin
2008-10-04 0:27 ` Nakajima, Jun
2008-10-04 0:35 ` H. Peter Anvin
2008-10-07 22:30 ` Nakajima, Jun
2008-10-07 22:37 ` H. Peter Anvin
2008-10-07 23:45 ` Jeremy Fitzhardinge
2008-10-08 1:09 ` H. Peter Anvin
2008-10-07 23:41 ` Jeremy Fitzhardinge
2008-10-07 23:45 ` H. Peter Anvin
2008-10-08 0:40 ` Jeremy Fitzhardinge
2008-10-04 8:53 ` Avi Kivity
2008-10-01 17:47 ` H. Peter Anvin
2008-10-01 18:04 ` Jeremy Fitzhardinge
2008-10-01 18:07 ` H. Peter Anvin
2008-10-01 18:12 ` Jeremy Fitzhardinge
2008-10-01 18:16 ` H. Peter Anvin
2008-10-01 18:36 ` Jeremy Fitzhardinge
2008-10-01 18:43 ` H. Peter Anvin
2008-10-01 19:56 ` Jeremy Fitzhardinge
2008-10-01 20:38 ` Chris Wright
2008-10-01 22:38 ` H. Peter Anvin
2008-10-01 21:01 ` Alok Kataria
2008-10-01 21:08 ` Anthony Liguori
2008-10-01 21:15 ` Chris Wright
2008-10-01 21:31 ` Anthony Liguori
2008-10-01 21:23 ` Alok Kataria
2008-10-01 21:29 ` Anthony Liguori
2008-10-01 21:17 ` Jeremy Fitzhardinge
2008-10-01 21:34 ` Anthony Liguori [this message]
2008-10-01 21:43 ` Chris Wright
2008-10-02 11:29 ` Avi Kivity
2008-10-01 23:47 ` Zachary Amsden
2008-10-02 0:39 ` H. Peter Anvin
2008-10-02 0:57 ` H. Peter Anvin
2008-10-02 1:11 ` Zachary Amsden
2008-10-02 1:21 ` H. Peter Anvin
2008-10-02 0:41 ` Anthony Liguori
[not found] ` <48E3BBC1.2050607__35819.6151479662$1222884502$gmane$org@goop.org>
2008-10-01 20:03 ` Anthony Liguori
2008-10-01 20:08 ` Jeremy Fitzhardinge
[not found] ` <48E3D8A8.604__13396.6479487301$1222891831$gmane$org@goop.org>
2008-10-01 21:03 ` Anthony Liguori
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