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 | 30 ++++++++++++++++++++++++++++++ include/hw/i386/x86.h | 7 +++++++ target/i386/cpu.c | 14 ++++++++++++++ 4 files changed, 59 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 3137a2008588..eeecd4e3322f 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -1171,6 +1171,20 @@ 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); @@ -1193,6 +1207,16 @@ 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->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); @@ -1204,6 +1228,12 @@ 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 d5dcf7a07fdc..2b989e5fc49d 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 hyperv_features; }; struct X86MachineState { @@ -70,10 +73,14 @@ 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) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 55706c8050fe..d0961c1838ad 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -53,6 +53,7 @@ #include "sysemu/tcg.h" #include "hw/qdev-properties.h" #include "hw/i386/topology.h" +#include "hw/i386/x86.h" #ifndef CONFIG_USER_ONLY #include "exec/address-spaces.h" #include "hw/i386/apic_internal.h" @@ -6409,8 +6410,21 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool verbose) static void x86_cpu_hyperv_realize(X86CPU *cpu) { + X86MachineState *x86ms = X86_MACHINE(qdev_get_machine()); + X86MachineClass *x86mc = X86_MACHINE_GET_CLASS(x86ms); + uint64_t feat; size_t len; + if (x86ms->hyperv_enabled) { + feat = x86mc->hyperv_features; + /* Enlightened VMCS is only available on Intel/VMX */ + if (!cpu_has_vmx(&cpu->env)) { + feat &= ~BIT(HYPERV_FEAT_EVMCS); + } + + cpu->hyperv_features |= feat; + } + /* Hyper-V vendor id */ if (!cpu->hyperv_vendor) { object_property_set_str(OBJECT(cpu), "hv-vendor-id", "Microsoft Hv", -- 2.25.4