Enabling Hyper-V emulation for a Windows VM is a tiring experience as it
requires listing all currently supported enlightenments ("hv_*" CPU
features) explicitly. We do have a 'hv_passthrough' mode enabling
everything but it can't be used in production as it prevents migration.
Introduce a simple 'hyperv=on' option for all x86 machine types enabling
all currently supported Hyper-V enlightenments. Later, when new
enlightenments get implemented, we will be adding them to newer machine
types only (by disabling them for legacy machine types) thus preserving
migration.
Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
---
docs/hyperv.txt | 8 ++++++++
hw/i386/x86.c | 42 ++++++++++++++++++++++++++++++++++++++++++
include/hw/i386/x86.h | 7 +++++++
3 files changed, 57 insertions(+)
diff --git a/docs/hyperv.txt b/docs/hyperv.txt
index 5df00da54fc4..1a76a07f8417 100644
--- a/docs/hyperv.txt
+++ b/docs/hyperv.txt
@@ -29,6 +29,14 @@ When any set of the Hyper-V enlightenments is enabled, QEMU
changes hypervisor
identification (CPUID 0x40000000..0x4000000A) to Hyper-V. KVM identification
and features are kept in leaves 0x40000100..0x40000101.
+Hyper-V enlightenments can be enabled in bulk by specifying 'hyperv=on' to an
+x86 machine type:
+
+ qemu-system-x86_64 -machine q35,accel=kvm,kernel-irqchip=split,hyperv=on ...
+
+Note, new enlightenments are only added to the latest (in-develompent) machine
+type, older machine types keep the list of the supported features intact to
+safeguard migration.
3. Existing enlightenments
===========================
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 49e1d419b2ce..7a8e0313aedb 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -418,6 +418,18 @@ void x86_cpu_pre_plug(HotplugHandler *hotplug_dev,
cs->cpu_index = idx;
numa_cpu_pre_plug(cpu_slot, dev, errp);
+
+ if (x86ms->hyperv_enabled) {
+ X86MachineClass *x86mc = X86_MACHINE_GET_CLASS(x86ms);
+ uint64_t hyperv_features = x86mc->default_hyperv_features;
+
+ /* Enlightened VMCS is only available on Intel/VMX */
+ if (!kvm_hv_evmcs_available()) {
+ hyperv_features &= ~BIT(HYPERV_FEAT_EVMCS);
+ }
+
+ cpu->hyperv_features |= hyperv_features;
+ }
}
CpuInstanceProperties
@@ -1199,6 +1211,20 @@ static void x86_machine_set_acpi(Object *obj, Visitor
*v, const char *name,
visit_type_OnOffAuto(v, name, &x86ms->acpi, errp);
}
+static bool x86_machine_get_hyperv(Object *obj, Error **errp)
+{
+ X86MachineState *x86ms = X86_MACHINE(obj);
+
+ return x86ms->hyperv_enabled;
+}
+
+static void x86_machine_set_hyperv(Object *obj, bool value, Error **errp)
+{
+ X86MachineState *x86ms = X86_MACHINE(obj);
+
+ x86ms->hyperv_enabled = value;
+}
+
static void x86_machine_initfn(Object *obj)
{
X86MachineState *x86ms = X86_MACHINE(obj);
@@ -1222,6 +1248,16 @@ static void x86_machine_class_init(ObjectClass *oc, void
*data)
x86mc->save_tsc_khz = true;
nc->nmi_monitor_handler = x86_nmi;
+ /* Hyper-V features enabled with 'hyperv=on' */
+ x86mc->default_hyperv_features = BIT(HYPERV_FEAT_RELAXED) |
+ BIT(HYPERV_FEAT_VAPIC) | BIT(HYPERV_FEAT_TIME) |
+ BIT(HYPERV_FEAT_CRASH) | BIT(HYPERV_FEAT_RESET) |
+ BIT(HYPERV_FEAT_VPINDEX) | BIT(HYPERV_FEAT_RUNTIME) |
+ BIT(HYPERV_FEAT_SYNIC) | BIT(HYPERV_FEAT_STIMER) |
+ BIT(HYPERV_FEAT_FREQUENCIES) | BIT(HYPERV_FEAT_REENLIGHTENMENT) |
+ BIT(HYPERV_FEAT_TLBFLUSH) | BIT(HYPERV_FEAT_EVMCS) |
+ BIT(HYPERV_FEAT_IPI) | BIT(HYPERV_FEAT_STIMER_DIRECT);
+
object_class_property_add(oc, X86_MACHINE_SMM, "OnOffAuto",
x86_machine_get_smm, x86_machine_set_smm,
NULL, NULL);
@@ -1233,6 +1269,12 @@ static void x86_machine_class_init(ObjectClass *oc, void
*data)
NULL, NULL);
object_class_property_set_description(oc, X86_MACHINE_ACPI,
"Enable ACPI");
+
+ object_class_property_add_bool(oc, X86_MACHINE_HYPERV,
+ x86_machine_get_hyperv, x86_machine_set_hyperv);
+
+ object_class_property_set_description(oc, X86_MACHINE_HYPERV,
+ "Enable Hyper-V enlightenments");
}
static const TypeInfo x86_machine_info = {
diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
index 56080bd1fb14..c6e9c8500357 100644
--- a/include/hw/i386/x86.h
+++ b/include/hw/i386/x86.h
@@ -38,6 +38,9 @@ struct X86MachineClass {
bool save_tsc_khz;
/* Enables contiguous-apic-ID mode */
bool compat_apic_id_mode;
+
+ /* Hyper-V features enabled with 'hyperv=on' */
+ uint64_t default_hyperv_features;
};
struct X86MachineState {
@@ -72,10 +75,14 @@ struct X86MachineState {
* will be translated to MSI messages in the address space.
*/
AddressSpace *ioapic_as;
+
+ /* Hyper-V emulation */
+ bool hyperv_enabled;
};
#define X86_MACHINE_SMM "smm"
#define X86_MACHINE_ACPI "acpi"
+#define X86_MACHINE_HYPERV "hyperv"
#define TYPE_X86_MACHINE MACHINE_TYPE_NAME("x86")
OBJECT_DECLARE_TYPE(X86MachineState, X86MachineClass, X86_MACHINE)
--
2.29.2
