| Message ID | 20190828234134.132704-5-oupton@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: Add full nested support for IA32_PERF_GLOBAL_CTRL | expand |
On Wed, Aug 28, 2019 at 04:41:31PM -0700, Oliver Upton wrote: > According to the SDM 26.3.1.1, "If the "load IA32_PERF_GLOBAL_CTRL" VM-entry > control is 1, bits reserved in the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the > field for that register". > > Adding condition to nested_vmx_check_guest_state() to check the validity of > GUEST_IA32_PERF_GLOBAL_CTRL if the "load IA32_PERF_GLOBAL_CTRL" bit is > set on the VM-entry control. Same comment on mood. And for this case, it's probably overkill to give a play-by-play of the code, just state that you're adding a check as described in the SDM, e.g.: Add a nested VM-Enter consistency check when loading the guest's IA32_PERF_GLOBAL_CTRL MSR from vmcs12. Per Intel's SDM: If the "load IA32_PERF_GLOBAL_CTRL" VM-entry control is 1, bits reserved in the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the field for that register. > > Suggested-by: Jim Mattson <jmattson@google.com> > Signed-off-by: Oliver Upton <oupton@google.com> > --- > arch/x86/kvm/vmx/nested.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 9ba90b38d74b..8d6f0144b1bd 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -10,6 +10,7 @@ > #include "hyperv.h" > #include "mmu.h" > #include "nested.h" > +#include "pmu.h" > #include "trace.h" > #include "x86.h" > > @@ -2748,6 +2749,11 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, > return -EINVAL; > } > > + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL && > + !kvm_is_valid_perf_global_ctrl(vcpu, > + vmcs12->guest_ia32_perf_global_ctrl)) > + return -EINVAL; > + > /* > * If the load IA32_EFER VM-entry control is 1, the following checks > * are performed on the field for the IA32_EFER MSR: > -- > 2.23.0.187.g17f5b7556c-goog >
On Fri, Aug 30, 2019 at 11:37:03AM -0700, Sean Christopherson wrote: > On Wed, Aug 28, 2019 at 04:41:31PM -0700, Oliver Upton wrote: > > According to the SDM 26.3.1.1, "If the "load IA32_PERF_GLOBAL_CTRL" VM-entry > > control is 1, bits reserved in the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the > > field for that register". > > > > Adding condition to nested_vmx_check_guest_state() to check the validity of > > GUEST_IA32_PERF_GLOBAL_CTRL if the "load IA32_PERF_GLOBAL_CTRL" bit is > > set on the VM-entry control. > > Same comment on mood. And for this case, it's probably overkill to > give a play-by-play of the code, just state that you're adding a check > as described in the SDM, e.g.: > > Add a nested VM-Enter consistency check when loading the guest's > IA32_PERF_GLOBAL_CTRL MSR from vmcs12. Per Intel's SDM: > > If the "load IA32_PERF_GLOBAL_CTRL" VM-entry control is 1, bits > reserved in the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the field for > that register. Ack. This is a style problem throughout, I will make sure to address in the next set I send out. Thanks for the suggested text as well, reads a lot better than what I had before! > > > > Suggested-by: Jim Mattson <jmattson@google.com> > > Signed-off-by: Oliver Upton <oupton@google.com> > > --- > > arch/x86/kvm/vmx/nested.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > > index 9ba90b38d74b..8d6f0144b1bd 100644 > > --- a/arch/x86/kvm/vmx/nested.c > > +++ b/arch/x86/kvm/vmx/nested.c > > @@ -10,6 +10,7 @@ > > #include "hyperv.h" > > #include "mmu.h" > > #include "nested.h" > > +#include "pmu.h" > > #include "trace.h" > > #include "x86.h" > > > > @@ -2748,6 +2749,11 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, > > return -EINVAL; > > } > > > > + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL && > > + !kvm_is_valid_perf_global_ctrl(vcpu, > > + vmcs12->guest_ia32_perf_global_ctrl)) > > + return -EINVAL; > > + > > /* > > * If the load IA32_EFER VM-entry control is 1, the following checks > > * are performed on the field for the IA32_EFER MSR: > > -- > > 2.23.0.187.g17f5b7556c-goog > >
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 9ba90b38d74b..8d6f0144b1bd 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -10,6 +10,7 @@ #include "hyperv.h" #include "mmu.h" #include "nested.h" +#include "pmu.h" #include "trace.h" #include "x86.h" @@ -2748,6 +2749,11 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, return -EINVAL; } + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL && + !kvm_is_valid_perf_global_ctrl(vcpu, + vmcs12->guest_ia32_perf_global_ctrl)) + return -EINVAL; + /* * If the load IA32_EFER VM-entry control is 1, the following checks * are performed on the field for the IA32_EFER MSR:
According to the SDM 26.3.1.1, "If the "load IA32_PERF_GLOBAL_CTRL" VM-entry control is 1, bits reserved in the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the field for that register". Adding condition to nested_vmx_check_guest_state() to check the validity of GUEST_IA32_PERF_GLOBAL_CTRL if the "load IA32_PERF_GLOBAL_CTRL" bit is set on the VM-entry control. Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Oliver Upton <oupton@google.com> --- arch/x86/kvm/vmx/nested.c | 6 ++++++ 1 file changed, 6 insertions(+)