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authorVitaly Kuznetsov <vkuznets@redhat.com>2019-05-17 16:19:24 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2019-06-21 02:29:39 +0200
commit128531d9e10908a08761ed1ce10e607985d172d7 (patch)
tree8221bb01bfe2372edbdd2f801d7bc6ca8c6f91d3
parent8caba36db5d70beb5353b5b5d28421b67275bcf0 (diff)
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i386/kvm: add support for Direct Mode for Hyper-V synthetic timers
Hyper-V on KVM can only use Synthetic timers with Direct Mode (opting for an interrupt instead of VMBus message). This new capability is only announced in KVM_GET_SUPPORTED_HV_CPUID. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20190517141924.19024-10-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--docs/hyperv.txt10
-rw-r--r--target/i386/cpu.c2
-rw-r--r--target/i386/cpu.h1
-rw-r--r--target/i386/hyperv-proto.h1
-rw-r--r--target/i386/kvm.c9
5 files changed, 23 insertions, 0 deletions
diff --git a/docs/hyperv.txt b/docs/hyperv.txt
index beadb2d..8fdf25c 100644
--- a/docs/hyperv.txt
+++ b/docs/hyperv.txt
@@ -174,6 +174,16 @@ without the feature to find out if enabling it is beneficial.
Requires: hv-vapic
+3.17. hv-stimer-direct
+=======================
+Hyper-V specification allows synthetic timer operation in two modes: "classic",
+when expiration event is delivered as SynIC message and "direct", when the event
+is delivered via normal interrupt. It is known that nested Hyper-V can only
+use synthetic timers in direct mode and thus 'hv-stimer-direct' needs to be
+enabled.
+
+Requires: hv-vpindex, hv-synic, hv-time, hv-stimer
+
4. Development features
========================
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index e07996c..7beb8ab 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5883,6 +5883,8 @@ static Property x86_cpu_properties[] = {
HYPERV_FEAT_EVMCS, 0),
DEFINE_PROP_BIT64("hv-ipi", X86CPU, hyperv_features,
HYPERV_FEAT_IPI, 0),
+ DEFINE_PROP_BIT64("hv-stimer-direct", X86CPU, hyperv_features,
+ HYPERV_FEAT_STIMER_DIRECT, 0),
DEFINE_PROP_BOOL("hv-passthrough", X86CPU, hyperv_passthrough, false),
DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true),
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 86edbf5..7470acf 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -749,6 +749,7 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
#define HYPERV_FEAT_TLBFLUSH 11
#define HYPERV_FEAT_EVMCS 12
#define HYPERV_FEAT_IPI 13
+#define HYPERV_FEAT_STIMER_DIRECT 14
#ifndef HYPERV_SPINLOCK_NEVER_RETRY
#define HYPERV_SPINLOCK_NEVER_RETRY 0xFFFFFFFF
diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h
index c0272b3..cffac10 100644
--- a/target/i386/hyperv-proto.h
+++ b/target/i386/hyperv-proto.h
@@ -49,6 +49,7 @@
#define HV_GUEST_IDLE_STATE_AVAILABLE (1u << 5)
#define HV_FREQUENCY_MSRS_AVAILABLE (1u << 8)
#define HV_GUEST_CRASH_MSR_AVAILABLE (1u << 10)
+#define HV_STIMER_DIRECT_MODE_AVAILABLE (1u << 19)
/*
* HV_CPUID_ENLIGHTMENT_INFO.EAX bits
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 86de510..a323b1f 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -802,6 +802,14 @@ static struct {
},
.dependencies = BIT(HYPERV_FEAT_VPINDEX)
},
+ [HYPERV_FEAT_STIMER_DIRECT] = {
+ .desc = "direct mode synthetic timers (hv-stimer-direct)",
+ .flags = {
+ {.fw = FEAT_HYPERV_EDX,
+ .bits = HV_STIMER_DIRECT_MODE_AVAILABLE}
+ },
+ .dependencies = BIT(HYPERV_FEAT_STIMER)
+ },
};
static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max)
@@ -1124,6 +1132,7 @@ static int hyperv_handle_properties(CPUState *cs,
r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_TLBFLUSH);
r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_EVMCS);
r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_IPI);
+ r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_STIMER_DIRECT);
/* Additional dependencies not covered by kvm_hyperv_properties[] */
if (hyperv_feat_enabled(cpu, HYPERV_FEAT_SYNIC) &&