From: Arjan van de Ven <arjan@infradead.org>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Jan Beulich <jbeulich@novell.com>,
Xen-devel <xen-devel@lists.xensource.com>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [Xen-devel] [PATCH 10/24] xen: mask XSAVE from cpuid
Date: Sun, 15 Mar 2009 17:09:45 -0700 [thread overview]
Message-ID: <20090315170945.08344b86@infradead.org> (raw)
In-Reply-To: <49BD97C6.2070401@goop.org>
On Sun, 15 Mar 2009 17:05:26 -0700
Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> Arjan van de Ven wrote:
> > This is indicative of something that might be a huge bug in Xen:
> > Xen should never ever pass through CPUID bits it does not know.
> > If Xen does not honor that, there is a fundamental and eternally
> > recurring problem.... every time something new gets introduced Xen
> > likely breaks.
>
> Yes, I'd agree; Xen should whitelist cpu capabilities rather than
> blacklist them. Jan expressed the opposite opinion (on the grounds
> that it precludes using features which don't require special OS or
> hypervisor support without Xen modifications).
Well.. pretty much all new instructions need Xen modifications due to
the need to be emulate to deal with traps/vmexits/etc right?
So I don't quite see many cpuid bits that would NOT involve some Xen
modification or another ;)
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2009-03-16 0:11 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-13 8:11 [GIT PULL] 2.6.30 Xen core updates Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 01/24] xen: disable preempt for leave_lazy_mmu Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 02/24] xen: separate p2m allocation from setting Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 03/24] xen: dynamically allocate p2m tables Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 04/24] xen: split construction of p2m mfn tables from registration Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 05/24] xen: clean up xen_load_gdt Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 06/24] xen: make xen_load_gdt simpler Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 07/24] xen: remove xen_load_gdt debug Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 08/24] xen: reserve i386 Xen pagetables Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 09/24] NULL noise: arch/x86/xen/smp.c Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 10/24] xen: mask XSAVE from cpuid Jeremy Fitzhardinge
2009-03-13 9:50 ` [Xen-devel] " Jan Beulich
2009-03-13 15:13 ` Jeremy Fitzhardinge
2009-03-15 18:45 ` H. Peter Anvin
2009-03-15 21:03 ` Jeremy Fitzhardinge
2009-03-15 22:47 ` Arjan van de Ven
2009-03-16 0:05 ` Jeremy Fitzhardinge
2009-03-16 0:09 ` Arjan van de Ven [this message]
2009-03-16 0:57 ` H. Peter Anvin
2009-03-16 14:16 ` Jan Beulich
2009-03-16 14:29 ` Arjan van de Ven
2009-03-16 23:59 ` Andi Kleen
2009-03-17 1:33 ` H. Peter Anvin
2009-03-17 11:56 ` Andi Kleen
2009-03-17 15:48 ` H. Peter Anvin
2009-03-17 15:49 ` Arjan van de Ven
2009-03-17 15:55 ` Andi Kleen
2009-03-17 7:53 ` Jan Beulich
2009-03-17 10:48 ` Andi Kleen
2009-03-17 10:55 ` Jan Beulich
2009-03-13 8:11 ` [PATCH 11/24] xen: add FIX_TEXT_POKE to fixmap Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 12/24] x86-64: remove PGE from must-have feature list Jeremy Fitzhardinge
2009-03-15 21:18 ` H. Peter Anvin
2009-03-15 21:25 ` Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 13/24] Xen: Add virt_to_pfn helper function Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 14/24] xen: add irq_from_evtchn Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 15/24] xen: add /dev/xen/evtchn driver Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 16/24] xen: export ioctl headers to userspace Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 17/24] xen/dev-evtchn: clean up locking in evtchn Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 18/24] xen: add "capabilities" file Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 19/24] xen: add /sys/hypervisor support Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 20/24] xen/sys/hypervisor: change writable_pt to features Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 21/24] xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 22/24] xen: remove suspend_cancel hook Jeremy Fitzhardinge
2009-03-13 10:08 ` [Xen-devel] " Jan Beulich
2009-03-13 15:17 ` Jeremy Fitzhardinge
2009-03-13 8:11 ` [PATCH 23/24] xen: use device model for suspending xenbus devices Jeremy Fitzhardinge
2009-03-13 10:09 ` [Xen-devel] [PATCH 23/24] xen: use device model for suspendingxenbus devices Jan Beulich
2009-03-13 8:12 ` [PATCH 24/24] xen/xenbus: export xenbus_dev_changed Jeremy Fitzhardinge
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