[PATCH 4/4] KVM: hyper-v: Advertise support for fast XMM hypercalls

Siddharth Chandrasekaran
2021-04-07T21:21:26Z

Now that all extant hypercalls that can use XMM registers (based on
spec) for input/outputs are patched to support them, 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>
---
arch/x86/include/asm/hyperv-tlfs.h | 4 ++--
arch/x86/kvm/hyperv.c | 1 +
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index e6cd3fee562b..1f160ef60509 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -49,10 +49,10 @@
/* Support for physical CPU dynamic partitioning events is available*/
#define HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE BIT(3)
/*
- * Support for passing hypercall input parameter block via XMM
+ * Support for passing hypercall input and output parameter block via XMM
* registers is available
*/
-#define HV_X64_HYPERCALL_PARAMS_XMM_AVAILABLE BIT(4)
+#define HV_X64_HYPERCALL_PARAMS_XMM_AVAILABLE BIT(4) | BIT(15)
/* Support for a virtual guest idle state is available */
#define HV_X64_GUEST_IDLE_STATE_AVAILABLE BIT(5)
/* Frequency MSRs available */
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index bf2f86f263f1..dd462c1d641d 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2254,6 +2254,7 @@ 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_PARAMS_XMM_AVAILABLE;
ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;

--
2.17.1