| Message ID | CAB5KdOZwZUvgmHX5C53SBU0WttEF4wBFpgqiGahD2OkojQJZ-Q@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: SVM: Fix svm the vmexit error_code of WRMSR | expand |
Haiwei Li <lihaiwei.kernel@gmail.com> writes: > From 1f755f75dfd73ad7cabb0e0f43e9993dd9f69120 Mon Sep 17 00:00:00 2001 > From: Haiwei Li <lihaiwei@tencent.com> > Date: Mon, 2 Mar 2020 19:19:59 +0800 > Subject: [PATCH] KVM: SVM: Fix svm the vmexit error_code of WRMSR > > In svm, exit_code of write_msr is not EXIT_REASON_MSR_WRITE which > belongs to vmx. EXIT_REASON_MSR_WRITE is '32', in SVM this corresponds to SVM_EXIT_READ_DR0. There were issues I guess. Or did you only detect that the fastpath is not working? > > According to amd manual, SVM_EXIT_MSR(7ch) is the exit_code of VMEXIT_MSR > due to RDMSR or WRMSR access to protected MSR. Additionally, the processor > indicates in the VMCB's EXITINFO1 whether a RDMSR(EXITINFO1=0) or > WRMSR(EXITINFO1=1) was intercepted. > > Signed-off-by: Haiwei Li <lihaiwei@tencent.com> Fixes: 1e9e2622a149 ("KVM: VMX: FIXED+PHYSICAL mode single target IPI fastpath") > --- > arch/x86/kvm/svm.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index fd3fc9f..ef71755 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -6296,7 +6296,8 @@ static void svm_handle_exit_irqoff(struct kvm_vcpu > *vcpu, > enum exit_fastpath_completion *exit_fastpath) > { > if (!is_guest_mode(vcpu) && > - to_svm(vcpu)->vmcb->control.exit_code == > EXIT_REASON_MSR_WRITE) There is an extra newline here (in case it's not just me). > + (to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR) && > + (to_svm(vcpu)->vmcb->control.exit_info_1 & 1)) Could we add defines for '1' and '0', like SVM_EXITINFO_MSR_WRITE/SVM_EXITINFO_MSR_READ maybe? > *exit_fastpath = handle_fastpath_set_msr_irqoff(vcpu); > } > > -- > 1.8.3.1 >
On 02/03/20 13:54, Vitaly Kuznetsov wrote: >> enum exit_fastpath_completion *exit_fastpath) >> { >> if (!is_guest_mode(vcpu) && >> - to_svm(vcpu)->vmcb->control.exit_code == >> EXIT_REASON_MSR_WRITE) > There is an extra newline here (in case it's not just me). Yes, the whole patch has broken newlines. I fixed it up and applied. >> + (to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR) && >> + (to_svm(vcpu)->vmcb->control.exit_info_1 & 1)) > > Could we add defines for '1' and '0', like > SVM_EXITINFO_MSR_WRITE/SVM_EXITINFO_MSR_READ maybe? We can eliminate "& 1" completely since that's what msr_interception does. Paolo
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index fd3fc9f..ef71755 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6296,7 +6296,8 @@ static void svm_handle_exit_irqoff(struct kvm_vcpu *vcpu, enum exit_fastpath_completion *exit_fastpath) { if (!is_guest_mode(vcpu) && - to_svm(vcpu)->vmcb->control.exit_code == EXIT_REASON_MSR_WRITE) + (to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR) && + (to_svm(vcpu)->vmcb->control.exit_info_1 & 1)) *exit_fastpath = handle_fastpath_set_msr_irqoff(vcpu);