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From: Gleb Natapov <gleb@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	kvm@vger.kernel.org
Subject: Re: [PATCH 3/8] KVM: Activate fpu on clts
Date: Thu, 4 Feb 2010 15:11:25 +0200	[thread overview]
Message-ID: <20100204131125.GF2471@redhat.com> (raw)
In-Reply-To: <4B6AC60D.5030905@redhat.com>

On Thu, Feb 04, 2010 at 03:05:17PM +0200, Avi Kivity wrote:
> On 02/02/2010 10:16 AM, Paolo Bonzini wrote:
> >On 01/21/2010 02:31 PM, Avi Kivity wrote:
> >>diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> >>index feca59f..09207ba 100644
> >>--- a/arch/x86/kvm/x86.c
> >>+++ b/arch/x86/kvm/x86.c
> >>@@ -3266,6 +3266,7 @@ int emulate_invlpg(struct kvm_vcpu *vcpu,
> >>gva_t address)
> >>  int emulate_clts(struct kvm_vcpu *vcpu)
> >>  {
> >>      kvm_x86_ops->set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~X86_CR0_TS));
> >>+    kvm_x86_ops->fpu_activate(vcpu);
> >>      return X86EMUL_CONTINUE;
> >>  }
> >
> >Can this code be reached if CLTS is executed in real mode?  That
> >would cause a NULL-pointer access on VMX.
> 
> How would this cause a null pointer access?
> 
vmx.c doesn't initialize kvm_x86_ops->fpu_activate as far as I see.

--
			Gleb.

  reply	other threads:[~2010-02-04 13:11 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-21 13:31 [PATCH 0/8] cr0/cr4/efer/fpu miscellaneous bits Avi Kivity
2010-01-21 13:31 ` [PATCH 1/8] KVM: Allow kvm_load_guest_fpu() even when !vcpu->fpu_active Avi Kivity
2010-01-21 13:31 ` [PATCH 2/8] KVM: Drop kvm_{load,put}_guest_fpu() exports Avi Kivity
2010-01-21 13:31 ` [PATCH 3/8] KVM: Activate fpu on clts Avi Kivity
2010-01-23 18:56   ` Marcelo Tosatti
2010-01-24  7:20     ` Avi Kivity
2010-02-02  8:16   ` Paolo Bonzini
2010-02-03 10:23     ` Gleb Natapov
2010-02-04 13:05     ` Avi Kivity
2010-02-04 13:11       ` Gleb Natapov [this message]
2010-02-04 17:56         ` Avi Kivity
2010-02-07 12:25           ` Avi Kivity
2010-01-21 13:31 ` [PATCH 4/8] KVM: Add a helper for checking if the guest is in protected mode Avi Kivity
2010-01-21 13:31 ` [PATCH 5/8] KVM: Move cr0/cr4/efer related helpers to x86.h Avi Kivity
2010-01-21 13:31 ` [PATCH 6/8] KVM: Rename vcpu->shadow_efer to efer Avi Kivity
2010-01-21 13:31 ` [PATCH 7/8] KVM: Optimize kvm_read_cr[04]_bits() Avi Kivity
2010-02-05  8:26   ` Jan Kiszka
2010-02-07 12:05     ` Avi Kivity
2010-02-07 12:33       ` Jan Kiszka
2010-02-07 12:37         ` Avi Kivity
2010-02-07 13:20           ` Jan Kiszka
2010-01-21 13:31 ` [PATCH 8/8] KVM: trace guest fpu loads and unloads Avi Kivity
2010-01-23 19:02 ` [PATCH 0/8] cr0/cr4/efer/fpu miscellaneous bits Marcelo Tosatti

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