[PATCH v2 4/4] KVM: hyper-v: Advertise support for fast XMM hypercalls

Siddharth Chandrasekaran
2021-04-12T17:02:59Z

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 | 7 ++++++-
arch/x86/kvm/hyperv.c | 2 ++
2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index e6cd3fee562b..716f12be411e 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/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 ouput 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)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 1f9959aba70d..55838c266bcd 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2254,6 +2254,8 @@ 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_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE;
ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;

--
2.17.1