Re: [PATCH v3 4/4] KVM: hyper-v: Advertise support for fast XMM hypercalls

From: Paolo Bonzini
Date: Mon May 24 2021 - 08:00:46 EST


On 13/04/21 23:50, Siddharth Chandrasekaran wrote:
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@xxxxxxxxxx>
Cc: Evgeny Iakovlev <eyakovl@xxxxxxxxx>
Signed-off-by: Siddharth Chandrasekaran <sidcha@xxxxxxxxx>
---
arch/x86/include/asm/hyperv-tlfs.h | 7 ++++++-
arch/x86/kvm/hyperv.c | 1 +
2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index ee6336a54f92..597ae1142864 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 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)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index cd6c6f1f06a4..0f6fd7550510 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2235,6 +2235,7 @@ 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;


Queued, thanks.

Paolo