From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: KVM: SVM: Disable Lazy FPU optimization because of regressions Date: Sun, 18 Nov 2007 19:28:56 +0200 Message-ID: <47407658.1010803@qumranet.com> References: <200711182244.51689.amit.shah@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Amit Shah Return-path: In-Reply-To: <200711182244.51689.amit.shah-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Amit Shah wrote: > >From 76204eda7e03035c16702105e78724137ecad24b Mon Sep 17 00:00:00 2001 > From: Amit Shah > Date: Sun, 18 Nov 2007 22:42:47 +0530 > Subject: [PATCH] KVM: SVM: Disable Lazy FPU optimization because of > regressions > > Host FPU state is leaked into the guest FPU state. This happens > because of the lazy FPU optimization, so just reload the FPU > each time there's a VM exit/entry. > > The real fix should follow soon. > > Applied, thanks, and: > diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c > index ea2cb83..d7c9b92 100644 > --- a/drivers/kvm/svm.c > +++ b/drivers/kvm/svm.c > @@ -1600,11 +1600,11 @@ static void svm_set_cr3(struct kvm_vcpu *vcpu, > unsigned long root) > svm->vmcb->save.cr3 = root; > force_new_asid(vcpu); > > - if (vcpu->fpu_active) { > - svm->vmcb->control.intercept_exceptions |= (1 << NM_VECTOR); > - svm->vmcb->save.cr0 |= X86_CR0_TS; > - vcpu->fpu_active = 0; > - } > +/* if (vcpu->fpu_active) { */ > +/* svm->vmcb->control.intercept_exceptions |= (1 << NM_VECTOR); */ > +/* svm->vmcb->save.cr0 |= X86_CR0_TS; */ > +/* vcpu->fpu_active = 0; */ > +/* } */ > } > > static void svm_inject_page_fault(struct kvm_vcpu *vcpu, > Changed those into a #if 0. Those comments were unsightly. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/