From: Gleb Natapov <gleb@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>, kvm <kvm@vger.kernel.org>
Subject: Re: [PATCH] KVM: VMX: Translate interrupt shadow when waiting on NMI window
Date: Tue, 16 Feb 2010 12:06:35 +0200 [thread overview]
Message-ID: <20100216100635.GE2995@redhat.com> (raw)
In-Reply-To: <4B7A6D9A.5030900@siemens.com>
On Tue, Feb 16, 2010 at 11:04:10AM +0100, Jan Kiszka wrote:
> Gleb Natapov wrote:
> > On Tue, Feb 16, 2010 at 10:16:12AM +0100, Jan Kiszka wrote:
> >> Found while browsing Xen code: While we assume that the STI interrupt
> >> shadow also inplies virtual NMI blocking, some processors may have a
> >> different opinion (SDM 3: 22.3). To avoid misunderstandings that would
> >> cause endless VM entry attempts, translate STI into MOV SS blocking when
> >> requesting the NMI window.
> >>
> > Why not just remove "block by STI" check in vmx_nmi_allowed()? IIRC this
> > is documented that on some CPUs STI does not block NMI.
> >
>
> Probably because we will stumble and fall on those CPUs that do care.
>
But this defines behaviour of cpu _we_ emulate. So on _our_ cpu NMI will
not be blocked by STI.
--
Gleb.
next prev parent reply other threads:[~2010-02-16 10:06 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-16 9:16 [PATCH] KVM: VMX: Translate interrupt shadow when waiting on NMI window Jan Kiszka
2010-02-16 10:00 ` Gleb Natapov
2010-02-16 10:04 ` Jan Kiszka
2010-02-16 10:06 ` Gleb Natapov [this message]
2010-02-16 10:14 ` Jan Kiszka
2010-02-16 10:17 ` Gleb Natapov
2010-02-16 10:27 ` Jan Kiszka
2010-02-16 10:32 ` Gleb Natapov
2010-02-16 10:37 ` Jan Kiszka
2010-02-16 10:38 ` Gleb Natapov
2010-04-21 14:17 ` Jan Kiszka
2010-04-21 14:30 ` Gleb Natapov
2010-04-21 14:41 ` Jan Kiszka
2010-04-21 14:44 ` Gleb Natapov
2010-04-21 15:14 ` Jan Kiszka
2010-04-21 15:30 ` Gleb Natapov
2010-05-03 7:32 ` Gleb Natapov
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