KVM: hyper-v: Advertise support for fast XMM hypercalls

Now that kvm_hv_flush_tlb() has been patched to support XMM hypercall
inputs, we can start advertising this feature to guests.

Cc: Alexander Graf <graf@amazon.com>
Cc: Evgeny Iakovlev <eyakovl@amazon.de>
Signed-off-by: Siddharth Chandrasekaran <sidcha@amazon.de>
Message-Id: <e63fc1c61dd2efecbefef239f4f0a598bd552750.1622019134.git.sidcha@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/hyperv-tlfs.h

@@ -52,7 +52,7 @@
  * Support for passing hypercall input parameter block via XMM
  * registers is available
  */
-#define HV_X64_HYPERCALL_PARAMS_XMM_AVAILABLE		BIT(4)
+#define HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE		BIT(4)
 /* Support for a virtual guest idle state is available */
 #define HV_X64_GUEST_IDLE_STATE_AVAILABLE		BIT(5)
 /* Frequency MSRs available */
@@ -61,6 +61,11 @@
 #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE		BIT(10)
 /* Support for debug MSRs available */
 #define HV_FEATURE_DEBUG_MSRS_AVAILABLE			BIT(11)
+/*
+ * Support for returning hypercall output block via XMM
+ * registers is available
+ */
+#define HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE		BIT(15)
 /* stimer Direct Mode is available */
 #define HV_STIMER_DIRECT_MODE_AVAILABLE			BIT(19)
 

arch/x86/kvm/hyperv.c

@@ -2243,6 +2243,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
 			ent->ebx |= HV_POST_MESSAGES;
 			ent->ebx |= HV_SIGNAL_EVENTS;
 
+			ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;