On Fri, Mar 17, 2023 at 12:04:32PM -0700, Nathan Chancellor wrote:
> Hi Emanuele,
>
> On Wed, Feb 01, 2023 at 08:29:03AM -0500, Emanuele Giuseppe Esposito wrote:
> > Expose IA32_FLUSH_CMD to the guest if the guest CPUID enumerates
> > support for this MSR. As with IA32_PRED_CMD, permission for
> > unintercepted writes to this MSR will be granted to the guest after
> > the first non-zero write.
> >
> > Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> > Signed-off-by: Emanuele Giuseppe Esposito <eesposit@xxxxxxxxxx>
> > ---
> > arch/x86/kvm/vmx/nested.c | 3 ++
> > arch/x86/kvm/vmx/vmx.c | 70 +++++++++++++++++++++++++--------------
> > 2 files changed, 48 insertions(+), 25 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> > index 557b9c468734..075b5ade7c80 100644
> > --- a/arch/x86/kvm/vmx/nested.c
> > +++ b/arch/x86/kvm/vmx/nested.c
> > @@ -654,6 +654,9 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
> > nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
> > MSR_IA32_PRED_CMD, MSR_TYPE_W);
> >
> > + nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_FLUSH_CMD, MSR_TYPE_W);
> > +
> > kvm_vcpu_unmap(vcpu, &vmx->nested.msr_bitmap_map, false);
> >
> > vmx->nested.force_msr_bitmap_recalc = false;
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index c788aa382611..9a78ea96a6d7 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -2133,6 +2133,39 @@ static u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated
> > return debugctl;
> > }
> >
> > +static int vmx_set_msr_ia32_cmd(struct kvm_vcpu *vcpu,
> > + struct msr_data *msr_info,
> > + bool guest_has_feat, u64 cmd,
> > + int x86_feature_bit)
> > +{
> > + if (!msr_info->host_initiated && !guest_has_feat)
> > + return 1;
> > +
> > + if (!(msr_info->data & ~cmd))
Looks like this is doing a reverse check. Shouldn't this be as below:
---
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f88578407494..e8d9033559c4 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2141,7 +2141,7 @@ static int vmx_set_msr_ia32_cmd(struct kvm_vcpu *vcpu,
if (!msr_info->host_initiated && !guest_has_feat)
return 1;
- if (!(msr_info->data & ~cmd))
+ if (msr_info->data & ~cmd)
return 1;
if (!boot_cpu_has(x86_feature_bit))
return 1;
