Eduardo Habkost <ehabk...@redhat.com> writes: > On Fri, Oct 09, 2020 at 02:18:42PM +0200, Vitaly Kuznetsov wrote: >> 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> > > This patch seems to be especially useful, and I wonder if we > could make sure this is included before all the rest of the > series. Especially considering that the KVM changes might take a > while to be merged.
The required KVM changes are queued for 5.11 and I was delaying next submission till then. > > Would you be able to submit this independently from the rest of > the series? You can add my: > > Reviewed-by: Eduardo Habkost <ehabk...@redhat.com> > > My only (minor) suggestion is to rename > X86MachineClass.hyperv_features to > X86MachineClass.default_hyperv_features. Sure, will do. I'll probably pick a few small patches from the series (e.g. the one bringing x86_cpu_hyperv_realize()) to minimize the code churn in the future. > >> --- >> 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 >> -- Vitaly