From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Arjan van de Ven <arjan@infradead.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 17:05:26 -0700 [thread overview]
Message-ID: <49BD97C6.2070401@goop.org> (raw)
In-Reply-To: <20090315154718.00353625@infradead.org>
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). But if its just a matter of
sticking a bit into a mask, its easy and quick to roll a new version of
Xen (esp since it can generally be done before CPUs with the new feature
get into people's hands).
J
next prev parent reply other threads:[~2009-03-16 0:05 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 [this message]
2009-03-16 0:09 ` Arjan van de Ven
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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