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[Qemu-devel] [PATCH v2 9/9] i386/kvm: add support for Direct Mode for Hy
From: |
Vitaly Kuznetsov |
Subject: |
[Qemu-devel] [PATCH v2 9/9] i386/kvm: add support for Direct Mode for Hyper-V synthetic timers |
Date: |
Fri, 17 May 2019 16:19:24 +0200 |
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 <address@hidden>
---
docs/hyperv.txt | 10 ++++++++++
target/i386/cpu.c | 2 ++
target/i386/cpu.h | 1 +
target/i386/hyperv-proto.h | 1 +
target/i386/kvm.c | 9 +++++++++
5 files changed, 23 insertions(+)
diff --git a/docs/hyperv.txt b/docs/hyperv.txt
index beadb2d0d4..8fdf25c829 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 063551ef55..3cfd85758c 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5849,6 +5849,8 @@ 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 1f1f8969b4..0b6b781ecb 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -758,6 +758,7 @@ 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 c0272b3a01..cffac10b45 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 7ae2f63f72..fb29a3057b 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -803,6 +803,14 @@ 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)
@@ -1125,6 +1133,7 @@ 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) &&
--
2.20.1
- [Qemu-devel] [PATCH v2 0/9] i386/kvm/hyper-v: refactor and implement 'hv-stimer-direct' and 'hv-passthrough' enlightenments, Vitaly Kuznetsov, 2019/05/17
- [Qemu-devel] [PATCH v2 7/9] i386/kvm: hv-tlbflush/ipi require hv-vpindex, Vitaly Kuznetsov, 2019/05/17
- [Qemu-devel] [PATCH v2 6/9] i386/kvm: hv-stimer requires hv-time and hv-synic, Vitaly Kuznetsov, 2019/05/17
- [Qemu-devel] [PATCH v2 8/9] i386/kvm: hv-evmcs requires hv-vapic, Vitaly Kuznetsov, 2019/05/17
- [Qemu-devel] [PATCH v2 4/9] i386/kvm: document existing Hyper-V enlightenments, Vitaly Kuznetsov, 2019/05/17
- [Qemu-devel] [PATCH v2 2/9] i386/kvm: add support for KVM_GET_SUPPORTED_HV_CPUID, Vitaly Kuznetsov, 2019/05/17
[Qemu-devel] [PATCH v2 9/9] i386/kvm: add support for Direct Mode for Hyper-V synthetic timers,
Vitaly Kuznetsov <=
[Qemu-devel] [PATCH v2 3/9] i386/kvm: move Hyper-V CPUID filling to hyperv_handle_properties(), Vitaly Kuznetsov, 2019/05/17
[Qemu-devel] [PATCH v2 1/9] i386/kvm: convert hyperv enlightenments properties from bools to bits, Vitaly Kuznetsov, 2019/05/17
[Qemu-devel] [PATCH v2 5/9] i386/kvm: implement 'hv-passthrough' mode, Vitaly Kuznetsov, 2019/05/17