From: "Roedel, Joerg" <Joerg.Roedel@amd.com>
To: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"stable@kernel.org" <stable@kernel.org>
Subject: Re: [PATCH 1/2] KVM: SVM: Fix NMI path when NMI happens in guest mode
Date: Fri, 14 Jan 2011 14:36:02 +0100 [thread overview]
Message-ID: <20110114133602.GC23914@amd.com> (raw)
In-Reply-To: <4D2F5204.7020100@redhat.com>
On Thu, Jan 13, 2011 at 02:27:00PM -0500, Avi Kivity wrote:
> On 01/13/2011 05:51 PM, Roedel, Joerg wrote:
> > I also had a look at entry_64.S. The save_paranoid could not be the
> > cause because MSR_GS_BASE is already negative at this point. But the
> > re-schedule condition check at the end of the NMI handler code could
> > also not be the cause because the NMI happens while preemption (and
> > interrupts) are disabled (a re-schedule should also trigger
> > preempt-notifiers and restore KERNEL_GS_BASE).
> >
>
> I have it:
Cool, good catch. Thanks :)
The only use of load_gs_index in svm is the vcpu_put function. It is
sufficient to just swap the KERNEL_GS_BASE wrmsr and the load_gs_index
function calls in there to be safe.
Joerg
--
AMD Operating System Research Center
Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632
next prev parent reply other threads:[~2011-01-14 13:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-13 15:22 [PATCH 0/2] perf-kvm support for SVM Joerg Roedel
2011-01-13 15:22 ` [PATCH 1/2] KVM: SVM: Fix NMI path when NMI happens in guest mode Joerg Roedel
2011-01-13 15:42 ` Avi Kivity
2011-01-13 15:51 ` Roedel, Joerg
2011-01-13 19:27 ` Avi Kivity
2011-01-14 13:36 ` Roedel, Joerg [this message]
2011-01-13 15:48 ` Jan Kiszka
2011-01-13 15:52 ` Roedel, Joerg
2011-01-13 15:22 ` [PATCH 2/2] KVM: SVM: Add support for perf-kvm Joerg Roedel
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