| Message ID | 20210210164033.607612-21-vkuznets@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i386: KVM: expand Hyper-V features early and provide simple 'hv-default=on' option | expand |
On Wed, 10 Feb 2021 17:40:32 +0100 Vitaly Kuznetsov <vkuznets@redhat.com> 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 'hv-passthrough' mode enabling > everything but it can't be used in production as it prevents migration. > > Introduce a simple 'hv-default=on' CPU flag enabling all currently supported > Hyper-V enlightenments. Later, when new enlightenments get implemented, > compat_props mechanism will be used to disable them for legacy machine types, > this will keep 'hv-default=on' configurations migratable. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > docs/hyperv.txt | 16 ++++++++++++--- > target/i386/cpu.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ > target/i386/cpu.h | 3 +++ > 3 files changed, 68 insertions(+), 3 deletions(-) > > diff --git a/docs/hyperv.txt b/docs/hyperv.txt > index 5df00da54fc4..a54c066cab09 100644 > --- a/docs/hyperv.txt > +++ b/docs/hyperv.txt > @@ -17,10 +17,20 @@ compatible hypervisor and use Hyper-V specific features. > > 2. Setup > ========= > -No Hyper-V enlightenments are enabled by default by either KVM or QEMU. In > -QEMU, individual enlightenments can be enabled through CPU flags, e.g: > +All currently supported Hyper-V enlightenments can be enabled by specifying > +'hv-default=on' CPU flag: > > - qemu-system-x86_64 --enable-kvm --cpu host,hv_relaxed,hv_vpindex,hv_time, ... > + qemu-system-x86_64 --enable-kvm --cpu host,hv-default ... > + > +Alternatively, it is possible to do fine-grained enablement through CPU flags, > +e.g: > + > + qemu-system-x86_64 --enable-kvm --cpu host,hv-relaxed,hv-vpindex,hv-time ... > + > +It is also possible to disable individual enlightenments from the default list, > +this can be used for debugging purposes: > + > + qemu-system-x86_64 --enable-kvm --cpu host,hv-default=on,hv-evmcs=off ... > > Sometimes there are dependencies between enlightenments, QEMU is supposed to > check that the supplied configuration is sane. > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index f8df2caed779..013aa60272d8 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -4736,6 +4736,12 @@ static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) > { > X86CPU *cpu = X86_CPU(obj); > > + if (cpu->hyperv_default) { > + error_setg(errp, > + "'hv-default' and 'hv-paththrough' are mutually exclusive"); > + return; > + } > + > cpu->hyperv_passthrough = value; > > /* hv-passthrough overrides everything with what's supported by the host */ > @@ -4748,6 +4754,33 @@ static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) > return; > } > > +static bool x86_hv_default_get(Object *obj, Error **errp) > +{ > + X86CPU *cpu = X86_CPU(obj); > + > + return cpu->hyperv_default; > +} > + > +static void x86_hv_default_set(Object *obj, bool value, Error **errp) > +{ > + X86CPU *cpu = X86_CPU(obj); > + > + if (cpu->hyperv_passthrough) { > + error_setg(errp, > + "'hv-default' and 'hv-paththrough' are mutually exclusive"); this check will work only half way, i.e.: hv-paththrough=on,hv-default=on|off (where off value looks a bit wierd) but not other way around: hv-default=on,hv-paththrough=on were you thinking about following error: "hv-default can't be used after hv-paththrough were enabled" or if it symmetric, then putting this check in realizefn() will do the job as both properties are processed by that time. > + return; > + } > + > + cpu->hyperv_default = value; > + > + /* hv-default overrides everything with the default set */ > + if (value) { > + cpu->hyperv_features = cpu->hyperv_default_features; > + cpu->hyperv_features_on = 0; > + cpu->hyperv_features_off = 0; > + } > +} > + > /* Generic getter for "feature-words" and "filtered-features" properties */ > static void x86_cpu_get_feature_words(Object *obj, Visitor *v, > const char *name, void *opaque, > @@ -7152,6 +7185,21 @@ static void x86_cpu_initfn(Object *obj) > if (xcc->model) { > x86_cpu_load_model(cpu, xcc->model); > } > + > + /* Hyper-V features enabled with 'hv-default=on' */ > + cpu->hyperv_default_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_IPI) | > + BIT(HYPERV_FEAT_STIMER_DIRECT); > + > + /* Enlightened VMCS is only available on Intel/VMX */ > + if (kvm_hv_evmcs_available()) { > + cpu->hyperv_default_features |= BIT(HYPERV_FEAT_EVMCS); > + } > } > > static int64_t x86_cpu_get_arch_id(CPUState *cs) > @@ -7486,6 +7534,10 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data) > x86_hv_passthrough_get, > x86_hv_passthrough_set); > > + object_class_property_add_bool(oc, "hv-default", > + x86_hv_default_get, > + x86_hv_default_set); > + > for (w = 0; w < FEATURE_WORDS; w++) { > int bitnr; > for (bitnr = 0; bitnr < 64; bitnr++) { > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index b4fbd46f0fc9..59350e70fb51 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -1670,6 +1670,9 @@ struct X86CPU { > uint64_t hyperv_features_on; > uint64_t hyperv_features_off; > bool hyperv_passthrough; > + /* 'hv-default' enablement */ > + uint64_t hyperv_default_features; > + bool hyperv_default; > OnOffAuto hyperv_no_nonarch_cs; > uint32_t hyperv_vendor_id[3]; > uint32_t hyperv_interface_id[4];
Igor Mammedov <imammedo@redhat.com> writes: > On Wed, 10 Feb 2021 17:40:32 +0100 > Vitaly Kuznetsov <vkuznets@redhat.com> 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 'hv-passthrough' mode enabling >> everything but it can't be used in production as it prevents migration. >> >> Introduce a simple 'hv-default=on' CPU flag enabling all currently supported >> Hyper-V enlightenments. Later, when new enlightenments get implemented, >> compat_props mechanism will be used to disable them for legacy machine types, >> this will keep 'hv-default=on' configurations migratable. >> >> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> >> --- >> docs/hyperv.txt | 16 ++++++++++++--- >> target/i386/cpu.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ >> target/i386/cpu.h | 3 +++ >> 3 files changed, 68 insertions(+), 3 deletions(-) >> >> diff --git a/docs/hyperv.txt b/docs/hyperv.txt >> index 5df00da54fc4..a54c066cab09 100644 >> --- a/docs/hyperv.txt >> +++ b/docs/hyperv.txt >> @@ -17,10 +17,20 @@ compatible hypervisor and use Hyper-V specific features. >> >> 2. Setup >> ========= >> -No Hyper-V enlightenments are enabled by default by either KVM or QEMU. In >> -QEMU, individual enlightenments can be enabled through CPU flags, e.g: >> +All currently supported Hyper-V enlightenments can be enabled by specifying >> +'hv-default=on' CPU flag: >> >> - qemu-system-x86_64 --enable-kvm --cpu host,hv_relaxed,hv_vpindex,hv_time, ... >> + qemu-system-x86_64 --enable-kvm --cpu host,hv-default ... >> + >> +Alternatively, it is possible to do fine-grained enablement through CPU flags, >> +e.g: >> + >> + qemu-system-x86_64 --enable-kvm --cpu host,hv-relaxed,hv-vpindex,hv-time ... >> + >> +It is also possible to disable individual enlightenments from the default list, >> +this can be used for debugging purposes: >> + >> + qemu-system-x86_64 --enable-kvm --cpu host,hv-default=on,hv-evmcs=off ... >> >> Sometimes there are dependencies between enlightenments, QEMU is supposed to >> check that the supplied configuration is sane. >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c >> index f8df2caed779..013aa60272d8 100644 >> --- a/target/i386/cpu.c >> +++ b/target/i386/cpu.c >> @@ -4736,6 +4736,12 @@ static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) >> { >> X86CPU *cpu = X86_CPU(obj); >> >> + if (cpu->hyperv_default) { ^^^ here ^^^ >> + error_setg(errp, >> + "'hv-default' and 'hv-paththrough' are mutually exclusive"); >> + return; >> + } >> + >> cpu->hyperv_passthrough = value; >> >> /* hv-passthrough overrides everything with what's supported by the host */ >> @@ -4748,6 +4754,33 @@ static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) >> return; >> } >> >> +static bool x86_hv_default_get(Object *obj, Error **errp) >> +{ >> + X86CPU *cpu = X86_CPU(obj); >> + >> + return cpu->hyperv_default; >> +} >> + >> +static void x86_hv_default_set(Object *obj, bool value, Error **errp) >> +{ >> + X86CPU *cpu = X86_CPU(obj); >> + >> + if (cpu->hyperv_passthrough) { >> + error_setg(errp, >> + "'hv-default' and 'hv-paththrough' are mutually exclusive"); > this check will work only half way, i.e.: hv-paththrough=on,hv-default=on|off > (where off value looks a bit wierd) > but not other way around: hv-default=on,hv-paththrough=on The check in x86_hv_passthrough_set() chechs the opposite scenario. > > were you thinking about following error: > "hv-default can't be used after hv-paththrough were enabled" > > or if it symmetric, then putting this check in realizefn() will do the job > as both properties are processed by that time. I can move the check there but I think that two checks I add here cover what we need (and we don't need to care what to set 'hyperv_features' to in the interim). > >> + return; >> + } >> + >> + cpu->hyperv_default = value; >> + >> + /* hv-default overrides everything with the default set */ >> + if (value) { >> + cpu->hyperv_features = cpu->hyperv_default_features; >> + cpu->hyperv_features_on = 0; >> + cpu->hyperv_features_off = 0; >> + } >> +} >> + >> /* Generic getter for "feature-words" and "filtered-features" properties */ >> static void x86_cpu_get_feature_words(Object *obj, Visitor *v, >> const char *name, void *opaque, >> @@ -7152,6 +7185,21 @@ static void x86_cpu_initfn(Object *obj) >> if (xcc->model) { >> x86_cpu_load_model(cpu, xcc->model); >> } >> + >> + /* Hyper-V features enabled with 'hv-default=on' */ >> + cpu->hyperv_default_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_IPI) | >> + BIT(HYPERV_FEAT_STIMER_DIRECT); >> + >> + /* Enlightened VMCS is only available on Intel/VMX */ >> + if (kvm_hv_evmcs_available()) { >> + cpu->hyperv_default_features |= BIT(HYPERV_FEAT_EVMCS); >> + } >> } >> >> static int64_t x86_cpu_get_arch_id(CPUState *cs) >> @@ -7486,6 +7534,10 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data) >> x86_hv_passthrough_get, >> x86_hv_passthrough_set); >> >> + object_class_property_add_bool(oc, "hv-default", >> + x86_hv_default_get, >> + x86_hv_default_set); >> + >> for (w = 0; w < FEATURE_WORDS; w++) { >> int bitnr; >> for (bitnr = 0; bitnr < 64; bitnr++) { >> diff --git a/target/i386/cpu.h b/target/i386/cpu.h >> index b4fbd46f0fc9..59350e70fb51 100644 >> --- a/target/i386/cpu.h >> +++ b/target/i386/cpu.h >> @@ -1670,6 +1670,9 @@ struct X86CPU { >> uint64_t hyperv_features_on; >> uint64_t hyperv_features_off; >> bool hyperv_passthrough; >> + /* 'hv-default' enablement */ >> + uint64_t hyperv_default_features; >> + bool hyperv_default; >> OnOffAuto hyperv_no_nonarch_cs; >> uint32_t hyperv_vendor_id[3]; >> uint32_t hyperv_interface_id[4]; >
diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 5df00da54fc4..a54c066cab09 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -17,10 +17,20 @@ compatible hypervisor and use Hyper-V specific features. 2. Setup ========= -No Hyper-V enlightenments are enabled by default by either KVM or QEMU. In -QEMU, individual enlightenments can be enabled through CPU flags, e.g: +All currently supported Hyper-V enlightenments can be enabled by specifying +'hv-default=on' CPU flag: - qemu-system-x86_64 --enable-kvm --cpu host,hv_relaxed,hv_vpindex,hv_time, ... + qemu-system-x86_64 --enable-kvm --cpu host,hv-default ... + +Alternatively, it is possible to do fine-grained enablement through CPU flags, +e.g: + + qemu-system-x86_64 --enable-kvm --cpu host,hv-relaxed,hv-vpindex,hv-time ... + +It is also possible to disable individual enlightenments from the default list, +this can be used for debugging purposes: + + qemu-system-x86_64 --enable-kvm --cpu host,hv-default=on,hv-evmcs=off ... Sometimes there are dependencies between enlightenments, QEMU is supposed to check that the supplied configuration is sane. diff --git a/target/i386/cpu.c b/target/i386/cpu.c index f8df2caed779..013aa60272d8 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -4736,6 +4736,12 @@ static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) { X86CPU *cpu = X86_CPU(obj); + if (cpu->hyperv_default) { + error_setg(errp, + "'hv-default' and 'hv-paththrough' are mutually exclusive"); + return; + } + cpu->hyperv_passthrough = value; /* hv-passthrough overrides everything with what's supported by the host */ @@ -4748,6 +4754,33 @@ static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) return; } +static bool x86_hv_default_get(Object *obj, Error **errp) +{ + X86CPU *cpu = X86_CPU(obj); + + return cpu->hyperv_default; +} + +static void x86_hv_default_set(Object *obj, bool value, Error **errp) +{ + X86CPU *cpu = X86_CPU(obj); + + if (cpu->hyperv_passthrough) { + error_setg(errp, + "'hv-default' and 'hv-paththrough' are mutually exclusive"); + return; + } + + cpu->hyperv_default = value; + + /* hv-default overrides everything with the default set */ + if (value) { + cpu->hyperv_features = cpu->hyperv_default_features; + cpu->hyperv_features_on = 0; + cpu->hyperv_features_off = 0; + } +} + /* Generic getter for "feature-words" and "filtered-features" properties */ static void x86_cpu_get_feature_words(Object *obj, Visitor *v, const char *name, void *opaque, @@ -7152,6 +7185,21 @@ static void x86_cpu_initfn(Object *obj) if (xcc->model) { x86_cpu_load_model(cpu, xcc->model); } + + /* Hyper-V features enabled with 'hv-default=on' */ + cpu->hyperv_default_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_IPI) | + BIT(HYPERV_FEAT_STIMER_DIRECT); + + /* Enlightened VMCS is only available on Intel/VMX */ + if (kvm_hv_evmcs_available()) { + cpu->hyperv_default_features |= BIT(HYPERV_FEAT_EVMCS); + } } static int64_t x86_cpu_get_arch_id(CPUState *cs) @@ -7486,6 +7534,10 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data) x86_hv_passthrough_get, x86_hv_passthrough_set); + object_class_property_add_bool(oc, "hv-default", + x86_hv_default_get, + x86_hv_default_set); + for (w = 0; w < FEATURE_WORDS; w++) { int bitnr; for (bitnr = 0; bitnr < 64; bitnr++) { diff --git a/target/i386/cpu.h b/target/i386/cpu.h index b4fbd46f0fc9..59350e70fb51 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1670,6 +1670,9 @@ struct X86CPU { uint64_t hyperv_features_on; uint64_t hyperv_features_off; bool hyperv_passthrough; + /* 'hv-default' enablement */ + uint64_t hyperv_default_features; + bool hyperv_default; OnOffAuto hyperv_no_nonarch_cs; uint32_t hyperv_vendor_id[3]; uint32_t hyperv_interface_id[4];
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 'hv-passthrough' mode enabling everything but it can't be used in production as it prevents migration. Introduce a simple 'hv-default=on' CPU flag enabling all currently supported Hyper-V enlightenments. Later, when new enlightenments get implemented, compat_props mechanism will be used to disable them for legacy machine types, this will keep 'hv-default=on' configurations migratable. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- docs/hyperv.txt | 16 ++++++++++++--- target/i386/cpu.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ target/i386/cpu.h | 3 +++ 3 files changed, 68 insertions(+), 3 deletions(-)