From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 5/5] Notify nested hypervisor of lost event injections Date: Wed, 23 Sep 2009 03:22:13 +0200 Message-ID: <20090923012213.GB4654@8bytes.org> References: <1253278832-31803-1-git-send-email-agraf@suse.de> <1253278832-31803-2-git-send-email-agraf@suse.de> <1253278832-31803-3-git-send-email-agraf@suse.de> <1253278832-31803-4-git-send-email-agraf@suse.de> <1253278832-31803-5-git-send-email-agraf@suse.de> <1253278832-31803-6-git-send-email-agraf@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Alexander Graf Return-path: Received: from 8bytes.org ([88.198.83.132]:54391 "EHLO 8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753738AbZIWBWK (ORCPT ); Tue, 22 Sep 2009 21:22:10 -0400 Content-Disposition: inline In-Reply-To: <1253278832-31803-6-git-send-email-agraf@suse.de> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Sep 18, 2009 at 03:00:32PM +0200, Alexander Graf wrote: > Normally when event_inj is valid the host CPU would write the contents to > exit_int_info, so the hypervisor knows that the event wasn't injected. > > We failed to do so so far, so let's model closer to the CPU. > > Signed-off-by: Alexander Graf Acked-by: Joerg Roedel The commit-message does not state this explicitly, but this patch fixes a real bug with lost interrupts in nested svm. > --- > arch/x86/kvm/svm.c | 16 ++++++++++++++++ > 1 files changed, 16 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 12ec8ee..75e3d75 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -1643,6 +1643,22 @@ static int nested_svm_vmexit(struct vcpu_svm *svm) > nested_vmcb->control.exit_info_2 = vmcb->control.exit_info_2; > nested_vmcb->control.exit_int_info = vmcb->control.exit_int_info; > nested_vmcb->control.exit_int_info_err = vmcb->control.exit_int_info_err; > + > + /* > + * If we emulate a VMRUN/#VMEXIT in the same host #vmexit cycle we have > + * to make sure that we do not lose injected events. So check event_inj > + * here and copy it to exit_int_info if it is valid. > + * exit_int_info and event_inj can't be both valid because the below > + * case only happens on a VMRUN instruction intercept which has not > + * valid exit_int_info set. > + */ > + if (vmcb->control.event_inj & SVM_EVTINJ_VALID) { > + struct vmcb_control_area *nc = &nested_vmcb->control; > + > + nc->exit_int_info = vmcb->control.event_inj; > + nc->exit_int_info_err = vmcb->control.event_inj_err; > + } > + > nested_vmcb->control.tlb_ctl = 0; > nested_vmcb->control.event_inj = 0; > nested_vmcb->control.event_inj_err = 0; > -- > 1.6.0.2 > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html