| Message ID | 20181205000013.13474-2-krish.sadhukhan@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] KVM nVMX: MSRs should not be stored if VM-entry fails during or after loading guest state | expand |
On Tue, Dec 4, 2018 at 4:24 PM Krish Sadhukhan <krish.sadhukhan@oracle.com> wrote: > > According to section "VM-entry Failures During or After Loading Guest State" > in Intel SDM vol 3C, > > "No MSRs are saved into the VM-exit MSR-store area." > > when bit 31 of the exit reason is set. > > Reported-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> > Suggested-by: Jim Mattson <jmattson@google.com> > Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> > Reviewed-by: Darren Kenny <darren.kenny@oracle.com> > --- > arch/x86/kvm/vmx.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 4555077..4d153935 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -13827,6 +13827,18 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, > * L2 to IDT_VECTORING_INFO_FIELD. > */ > vmcs12_save_pending_event(vcpu, vmcs12); > + > + /* > + * According to spec, there's no need to store the guest's > + * MSRs if the exit is due to a VM-entry failure that occurs > + * during or after loading the guest state. Since this exit > + * does not fall in that category, we need to save the MSRs. > + */ I'm still not a fan of this comment, but it's good enough. Reviewed-by: Jim Mattson <jmattson@google.com>
On 05/12/18 01:00, Krish Sadhukhan wrote: > According to section "VM-entry Failures During or After Loading Guest State" > in Intel SDM vol 3C, > > "No MSRs are saved into the VM-exit MSR-store area." > > when bit 31 of the exit reason is set. > > Reported-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> > Suggested-by: Jim Mattson <jmattson@google.com> > Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> > Reviewed-by: Darren Kenny <darren.kenny@oracle.com> > --- > arch/x86/kvm/vmx.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 4555077..4d153935 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -13827,6 +13827,18 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, > * L2 to IDT_VECTORING_INFO_FIELD. > */ > vmcs12_save_pending_event(vcpu, vmcs12); > + > + /* > + * According to spec, there's no need to store the guest's > + * MSRs if the exit is due to a VM-entry failure that occurs > + * during or after loading the guest state. Since this exit > + * does not fall in that category, we need to save the MSRs. > + */ > + if (nested_vmx_store_msr(vcpu, > + vmcs12->vm_exit_msr_store_addr, > + vmcs12->vm_exit_msr_store_count)) > + nested_vmx_abort(vcpu, > + VMX_ABORT_SAVE_GUEST_MSR_FAIL); > } > > /* > @@ -14159,10 +14171,6 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, > * immutable. > */ > nested_flush_cached_shadow_vmcs12(vcpu, vmcs12); > - > - if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr, > - vmcs12->vm_exit_msr_store_count)) > - nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL); > } else { > /* > * The only expected VM-instruction error is "VM entry with > Queued, thanks. Paolo
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4555077..4d153935 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -13827,6 +13827,18 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, * L2 to IDT_VECTORING_INFO_FIELD. */ vmcs12_save_pending_event(vcpu, vmcs12); + + /* + * According to spec, there's no need to store the guest's + * MSRs if the exit is due to a VM-entry failure that occurs + * during or after loading the guest state. Since this exit + * does not fall in that category, we need to save the MSRs. + */ + if (nested_vmx_store_msr(vcpu, + vmcs12->vm_exit_msr_store_addr, + vmcs12->vm_exit_msr_store_count)) + nested_vmx_abort(vcpu, + VMX_ABORT_SAVE_GUEST_MSR_FAIL); } /* @@ -14159,10 +14171,6 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, * immutable. */ nested_flush_cached_shadow_vmcs12(vcpu, vmcs12); - - if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr, - vmcs12->vm_exit_msr_store_count)) - nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL); } else { /* * The only expected VM-instruction error is "VM entry with