From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH 1/4] KVM: MMU: fix forgot reserved bits check in speculative path Date: Tue, 13 Jul 2010 18:28:01 -0300 Message-ID: <20100713212801.GA6370@amt.cnet> References: <4C3C3518.7080505@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , LKML , KVM list To: Xiao Guangrong Return-path: Content-Disposition: inline In-Reply-To: <4C3C3518.7080505@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Tue, Jul 13, 2010 at 05:42:48PM +0800, Xiao Guangrong wrote: > In the speculative path, we should check guest pte's reserved bits just as > the real processor does > > Reported-by: Marcelo Tosatti > Signed-off-by: Xiao Guangrong > --- > arch/x86/kvm/mmu.c | 8 ++++++++ > arch/x86/kvm/paging_tmpl.h | 5 +++-- > 2 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index b93b94f..9fc1524 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2783,6 +2783,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, > break; > } > > + if (is_rsvd_bits_set(vcpu, gentry, PT_PAGE_TABLE_LEVEL)) > + gentry = 0; > + > mmu_guess_page_from_pte_write(vcpu, gpa, gentry); > spin_lock(&vcpu->kvm->mmu_lock); > if (atomic_read(&vcpu->kvm->arch.invlpg_counter) != invlpg_counter) > @@ -2851,6 +2854,11 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, > while (npte--) { > entry = *spte; > mmu_pte_write_zap_pte(vcpu, sp, spte); > + > + if (!!is_pae(vcpu) != sp->role.cr4_pae || > + is_nx(vcpu) != sp->role.nxe) > + continue; > + This breaks remote_flush assignment below.