i386: Hyper-V XMM fast hypercall input feature

Hyper-V specification allows to pass parameters for certain hypercalls
using XMM registers ("XMM Fast Hypercall Input"). When the feature is
in use, it allows for faster hypercalls processing as KVM can avoid
reading guest's memory.

KVM supports the feature since v5.14.

Rename HV_HYPERCALL_{PARAMS_XMM_AVAILABLE -> XMM_INPUT_AVAILABLE} to
comply with KVM.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220525115949.1294004-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/docs/hyperv.txt b/docs/hyperv.txt
index 5d85569b9941989abb167c117ff83c93117201a4..af1b10c0b3d183a36bd747bea0a3d5a2178ff4e8 100644 (file)
--- a/docs/hyperv.txt
+++ b/docs/hyperv.txt
@@ -249,6 +249,12 @@ Enlightened VMCS ('hv-evmcs') feature to also be enabled.
 
 Recommended: hv-evmcs (Intel)
 
+3.23. hv-xmm-input
+===================
+Hyper-V specification allows to pass parameters for certain hypercalls using XMM
+registers ("XMM Fast Hypercall Input"). When the feature is in use, it allows
+for faster hypercalls processing as KVM can avoid reading guest's memory.
+
 4. Supplementary features
 =========================
 

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 474e9b582ef36716a9fb357af892affdb73bf961..63cec0ea68daf955cf08d095d97eef89311387a7 100644 (file)
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6970,6 +6970,8 @@ static Property x86_cpu_properties[] = {
                       HYPERV_FEAT_AVIC, 0),
     DEFINE_PROP_BIT64("hv-emsr-bitmap", X86CPU, hyperv_features,
                       HYPERV_FEAT_MSR_BITMAP, 0),
+    DEFINE_PROP_BIT64("hv-xmm-input", X86CPU, hyperv_features,
+                      HYPERV_FEAT_XMM_INPUT, 0),
     DEFINE_PROP_ON_OFF_AUTO("hv-no-nonarch-coresharing", X86CPU,
                             hyperv_no_nonarch_cs, ON_OFF_AUTO_OFF),
     DEFINE_PROP_BIT64("hv-syndbg", X86CPU, hyperv_features,

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index c7882857366d08b460cdef56c34df5f09df08dd7..37e95535843b019308cccb55a72b1157eb7e9d0d 100644 (file)
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1107,6 +1107,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
 #define HYPERV_FEAT_AVIC                15
 #define HYPERV_FEAT_SYNDBG              16
 #define HYPERV_FEAT_MSR_BITMAP          17
+#define HYPERV_FEAT_XMM_INPUT           18
 
 #ifndef HYPERV_SPINLOCK_NEVER_NOTIFY
 #define HYPERV_SPINLOCK_NEVER_NOTIFY             0xFFFFFFFF

diff --git a/target/i386/kvm/hyperv-proto.h b/target/i386/kvm/hyperv-proto.h
index cea18dbc0e2341e0a63ca249cf951b278515b045..f5f16474fa2524be3aad04dc08dbc8ecf9e51f94 100644 (file)
--- a/target/i386/kvm/hyperv-proto.h
+++ b/target/i386/kvm/hyperv-proto.h
@@ -54,7 +54,7 @@
 #define HV_GUEST_DEBUGGING_AVAILABLE            (1u << 1)
 #define HV_PERF_MONITOR_AVAILABLE               (1u << 2)
 #define HV_CPU_DYNAMIC_PARTITIONING_AVAILABLE   (1u << 3)
-#define HV_HYPERCALL_PARAMS_XMM_AVAILABLE       (1u << 4)
+#define HV_HYPERCALL_XMM_INPUT_AVAILABLE        (1u << 4)
 #define HV_GUEST_IDLE_STATE_AVAILABLE           (1u << 5)
 #define HV_FREQUENCY_MSRS_AVAILABLE             (1u << 8)
 #define HV_GUEST_CRASH_MSR_AVAILABLE            (1u << 10)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f389bbedf204c2b9f765eecdd9ecfb26e98e8902..7e6f934eda68f28330d4210f8f6cbc7425cdd77d 100644 (file)
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -980,6 +980,13 @@ static struct {
              .bits = HV_NESTED_MSR_BITMAP}
         }
     },
+    [HYPERV_FEAT_XMM_INPUT] = {
+        .desc = "XMM fast hypercall input (hv-xmm-input)",
+        .flags = {
+            {.func = HV_CPUID_FEATURES, .reg = R_EDX,
+             .bits = HV_HYPERCALL_XMM_INPUT_AVAILABLE}
+        }
+    },
 };
 
 static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max,