From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH] KVM: SVM: Keep intercepting task switching with NPT
 enabled
Date: Thu, 27 Oct 2011 10:40:58 -0200
Message-ID: <20111027124058.GE29646@amt.cnet>
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Cc: Avi Kivity <avi@redhat.com>, kvm <kvm@vger.kernel.org>,
	"Roedel, Joerg" <Joerg.Roedel@amd.com>,
	Gleb Natapov <gleb@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
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On Tue, Oct 18, 2011 at 06:23:11PM +0200, Jan Kiszka wrote:
> AMD processors apparently have a bug in the hardware task switching
> support when NPT is enabled. If the task switch triggers a NPF, we can
> get wrong EXITINTINFO along with that fault. On resume, spurious
> exceptions may then be injected into the guest.
> 
> We were able to reproduce this bug when our guest triggered #SS and the
> handler were supposed to run over a separate task with not yet touched
> stack pages.
> 
> Work around the issue by continuing to emulate task switches even in
> NPT mode.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  arch/x86/kvm/svm.c |    1 -
>  1 files changed, 0 insertions(+), 1 deletions(-)

Applied, thanks.