| Message ID | 20200320212833.3507-9-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: TLB flushing fixes and enhancements | expand |
Sean Christopherson <sean.j.christopherson@intel.com> writes: > Skip the global INVVPID in the unlikely scenario that vpid==0 and the > SINGLE_CONTEXT variant of INVVPID is unsupported. If vpid==0, there's > no need to INVVPID as it's impossible to do VM-Enter with VPID enabled > and vmcs.VPID==0, i.e. there can't be any TLB entries for the vCPU with > vpid==0. The fact that the SINGLE_CONTEXT variant isn't supported is > irrelevant. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > arch/x86/kvm/vmx/ops.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/vmx/ops.h b/arch/x86/kvm/vmx/ops.h > index 45eaedee2ac0..33645a8e5463 100644 > --- a/arch/x86/kvm/vmx/ops.h > +++ b/arch/x86/kvm/vmx/ops.h > @@ -285,7 +285,7 @@ static inline void vpid_sync_context(int vpid) > { > if (cpu_has_vmx_invvpid_single()) > vpid_sync_vcpu_single(vpid); > - else > + else if (vpid != 0) > vpid_sync_vcpu_global(); > } Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> (personally, I also prefer 'vpid !=0' to '!vpid', however, nested.c uses expressions like '&& !vmcs12->virtual_processor_id' instead...)
diff --git a/arch/x86/kvm/vmx/ops.h b/arch/x86/kvm/vmx/ops.h index 45eaedee2ac0..33645a8e5463 100644 --- a/arch/x86/kvm/vmx/ops.h +++ b/arch/x86/kvm/vmx/ops.h @@ -285,7 +285,7 @@ static inline void vpid_sync_context(int vpid) { if (cpu_has_vmx_invvpid_single()) vpid_sync_vcpu_single(vpid); - else + else if (vpid != 0) vpid_sync_vcpu_global(); }
Skip the global INVVPID in the unlikely scenario that vpid==0 and the SINGLE_CONTEXT variant of INVVPID is unsupported. If vpid==0, there's no need to INVVPID as it's impossible to do VM-Enter with VPID enabled and vmcs.VPID==0, i.e. there can't be any TLB entries for the vCPU with vpid==0. The fact that the SINGLE_CONTEXT variant isn't supported is irrelevant. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/vmx/ops.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)