KVM: VMX: Drop redundant capability checks in low level INVVPID helpers

Remove the INVVPID capabilities checks from vpid_sync_vcpu_single() and
vpid_sync_vcpu_global() now that all callers ensure the INVVPID variant
is supported.  Note, in some cases the guarantee is provided in concert
with hardware_setup(), which enables VPID if and only if at least of
invvpid_single() or invvpid_global() is supported.

Drop the WARN_ON_ONCE() from vmx_flush_tlb() as vpid_sync_vcpu_single()
will trigger a WARN() on INVVPID failure, i.e. if SINGLE_CONTEXT isn't
supported.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200320212833.3507-13-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/ops.h

@@ -273,14 +273,12 @@ static inline void vpid_sync_vcpu_single(int vpid)
 	if (vpid == 0)
 		return;
 
-	if (cpu_has_vmx_invvpid_single())
-		__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vpid, 0);
+	__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vpid, 0);
 }
 
 static inline void vpid_sync_vcpu_global(void)
 {
-	if (cpu_has_vmx_invvpid_global())
-		__invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
+	__invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
 }
 
 static inline void vpid_sync_context(int vpid)

arch/x86/kvm/vmx/vmx.h

@@ -534,7 +534,6 @@ static inline void vmx_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa)
 			if (cpu_has_vmx_invvpid_global()) {
 				vpid_sync_vcpu_global();
 			} else {
-				WARN_ON_ONCE(!cpu_has_vmx_invvpid_single());
 				vpid_sync_vcpu_single(vmx->vpid);
 				vpid_sync_vcpu_single(vmx->nested.vpid02);
 			}