| Message ID | 20190621163422.6127-3-drjones@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target/arm/kvm: enable SVE in guests | expand |
Hi Drew, On 6/21/19 6:34 PM, Andrew Jones wrote: > We first convert the pmu property from a static property to one with > its own accessors. Then we use the set accessor to check if the PMU is > supported when using KVM. Indeed a 32-bit KVM host does not support > the PMU, so this check will catch an attempt to use it at property-set > time. > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > target/arm/cpu.c | 30 +++++++++++++++++++++++++----- > target/arm/kvm.c | 9 +++++++++ > target/arm/kvm_arm.h | 13 +++++++++++++ > 3 files changed, 47 insertions(+), 5 deletions(-) > > diff --git a/target/arm/cpu.c b/target/arm/cpu.c > index 376db154f008..858f668d226e 100644 > --- a/target/arm/cpu.c > +++ b/target/arm/cpu.c > @@ -759,10 +759,6 @@ static Property arm_cpu_has_el3_property = > static Property arm_cpu_cfgend_property = > DEFINE_PROP_BOOL("cfgend", ARMCPU, cfgend, false); > > -/* use property name "pmu" to match other archs and virt tools */ > -static Property arm_cpu_has_pmu_property = > - DEFINE_PROP_BOOL("pmu", ARMCPU, has_pmu, true); > - > static Property arm_cpu_has_vfp_property = > DEFINE_PROP_BOOL("vfp", ARMCPU, has_vfp, true); > > @@ -785,6 +781,29 @@ static Property arm_cpu_pmsav7_dregion_property = > pmsav7_dregion, > qdev_prop_uint32, uint32_t); > > +static bool arm_get_pmu(Object *obj, Error **errp) > +{ > + ARMCPU *cpu = ARM_CPU(obj); > + > + return cpu->has_pmu; > +} > + > +static void arm_set_pmu(Object *obj, bool value, Error **errp) > +{ > + ARMCPU *cpu = ARM_CPU(obj); > + > + if (value) { > + if (kvm_enabled() && !kvm_arm_pmu_supported(CPU(cpu))) { > + error_setg(errp, "'pmu' feature not supported by KVM on this host"); > + return; > + } > + set_feature(&cpu->env, ARM_FEATURE_PMU); > + } else { > + unset_feature(&cpu->env, ARM_FEATURE_PMU); > + } > + cpu->has_pmu = value; > +} > + > static void arm_get_init_svtor(Object *obj, Visitor *v, const char *name, > void *opaque, Error **errp) > { > @@ -859,7 +878,8 @@ void arm_cpu_post_init(Object *obj) > } > > if (arm_feature(&cpu->env, ARM_FEATURE_PMU)) { > - qdev_property_add_static(DEVICE(obj), &arm_cpu_has_pmu_property, > + cpu->has_pmu = true; > + object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu, > &error_abort); > } > > diff --git a/target/arm/kvm.c b/target/arm/kvm.c > index fe4f461d4ef6..69c961a4c62c 100644 > --- a/target/arm/kvm.c > +++ b/target/arm/kvm.c > @@ -162,6 +162,15 @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu) > env->features = arm_host_cpu_features.features; > } > > +bool kvm_arm_pmu_supported(CPUState *cpu) > +{ > + KVMState *s = KVM_STATE(current_machine->accelerator); > + int ret; > + > + ret = kvm_check_extension(s, KVM_CAP_ARM_PMU_V3); > + return ret > 0; return kvm_check_extension > +} > + > int kvm_arm_get_max_vm_ipa_size(MachineState *ms) > { > KVMState *s = KVM_STATE(ms->accelerator); > diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h > index 812125f805a1..e0ded3607996 100644 > --- a/target/arm/kvm_arm.h > +++ b/target/arm/kvm_arm.h > @@ -216,6 +216,14 @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu); > */ > bool kvm_arm_aarch32_supported(CPUState *cs); > > +/** > + * bool kvm_arm_pmu_supported: > + * @cs: CPUState kernel-doc comment style? > + * > + * Returns true if the KVM VCPU can enable its PMU and false otherwise. > + */ > +bool kvm_arm_pmu_supported(CPUState *cs); > + > /** > * kvm_arm_get_max_vm_ipa_size - Returns the number of bits in the > * IPA address space supported by KVM > @@ -261,6 +269,11 @@ static inline bool kvm_arm_aarch32_supported(CPUState *cs) > return false; > } > > +static inline bool kvm_arm_pmu_supported(CPUState *cs) > +{ > + return false; > +} > + > static inline int kvm_arm_get_max_vm_ipa_size(MachineState *ms) > { > return -ENOENT; > Reviewed-by: Eric Auger <eric.auger@redhat.com> Thanks Eric
On 6/21/19 6:34 PM, Andrew Jones wrote: > We first convert the pmu property from a static property to one with > its own accessors. Then we use the set accessor to check if the PMU is > supported when using KVM. Indeed a 32-bit KVM host does not support > the PMU, so this check will catch an attempt to use it at property-set > time. > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > target/arm/cpu.c | 30 +++++++++++++++++++++++++----- > target/arm/kvm.c | 9 +++++++++ > target/arm/kvm_arm.h | 13 +++++++++++++ > 3 files changed, 47 insertions(+), 5 deletions(-) > > diff --git a/target/arm/cpu.c b/target/arm/cpu.c > index 376db154f008..858f668d226e 100644 > --- a/target/arm/cpu.c > +++ b/target/arm/cpu.c > @@ -759,10 +759,6 @@ static Property arm_cpu_has_el3_property = > static Property arm_cpu_cfgend_property = > DEFINE_PROP_BOOL("cfgend", ARMCPU, cfgend, false); > > -/* use property name "pmu" to match other archs and virt tools */ > -static Property arm_cpu_has_pmu_property = > - DEFINE_PROP_BOOL("pmu", ARMCPU, has_pmu, true); > - > static Property arm_cpu_has_vfp_property = > DEFINE_PROP_BOOL("vfp", ARMCPU, has_vfp, true); > > @@ -785,6 +781,29 @@ static Property arm_cpu_pmsav7_dregion_property = > pmsav7_dregion, > qdev_prop_uint32, uint32_t); > > +static bool arm_get_pmu(Object *obj, Error **errp) > +{ > + ARMCPU *cpu = ARM_CPU(obj); > + > + return cpu->has_pmu; > +} > + > +static void arm_set_pmu(Object *obj, bool value, Error **errp) > +{ > + ARMCPU *cpu = ARM_CPU(obj); > + > + if (value) { > + if (kvm_enabled() && !kvm_arm_pmu_supported(CPU(cpu))) { > + error_setg(errp, "'pmu' feature not supported by KVM on this host"); > + return; > + } > + set_feature(&cpu->env, ARM_FEATURE_PMU); > + } else { > + unset_feature(&cpu->env, ARM_FEATURE_PMU); > + } > + cpu->has_pmu = value; > +} > + > static void arm_get_init_svtor(Object *obj, Visitor *v, const char *name, > void *opaque, Error **errp) > { > @@ -859,7 +878,8 @@ void arm_cpu_post_init(Object *obj) > } > > if (arm_feature(&cpu->env, ARM_FEATURE_PMU)) { > - qdev_property_add_static(DEVICE(obj), &arm_cpu_has_pmu_property, > + cpu->has_pmu = true; > + object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu, > &error_abort); This doesn't look right. The static property is only enabled here if the cpu is known to support the PMU, and thus the only useful setting is -cpu foo,pmu=off. Which means that the extra checking that you do in the dynamic property is unused. It seems like you need to be checking for the PMU earlier, e.g. in kvm_arm_get_host_cpu_features. r~
On Wed, Jun 26, 2019 at 11:49:03AM +0200, Richard Henderson wrote: > On 6/21/19 6:34 PM, Andrew Jones wrote: > > We first convert the pmu property from a static property to one with > > its own accessors. Then we use the set accessor to check if the PMU is > > supported when using KVM. Indeed a 32-bit KVM host does not support > > the PMU, so this check will catch an attempt to use it at property-set > > time. > > > > Signed-off-by: Andrew Jones <drjones@redhat.com> > > --- > > target/arm/cpu.c | 30 +++++++++++++++++++++++++----- > > target/arm/kvm.c | 9 +++++++++ > > target/arm/kvm_arm.h | 13 +++++++++++++ > > 3 files changed, 47 insertions(+), 5 deletions(-) > > > > diff --git a/target/arm/cpu.c b/target/arm/cpu.c > > index 376db154f008..858f668d226e 100644 > > --- a/target/arm/cpu.c > > +++ b/target/arm/cpu.c > > @@ -759,10 +759,6 @@ static Property arm_cpu_has_el3_property = > > static Property arm_cpu_cfgend_property = > > DEFINE_PROP_BOOL("cfgend", ARMCPU, cfgend, false); > > > > -/* use property name "pmu" to match other archs and virt tools */ > > -static Property arm_cpu_has_pmu_property = > > - DEFINE_PROP_BOOL("pmu", ARMCPU, has_pmu, true); > > - > > static Property arm_cpu_has_vfp_property = > > DEFINE_PROP_BOOL("vfp", ARMCPU, has_vfp, true); > > > > @@ -785,6 +781,29 @@ static Property arm_cpu_pmsav7_dregion_property = > > pmsav7_dregion, > > qdev_prop_uint32, uint32_t); > > > > +static bool arm_get_pmu(Object *obj, Error **errp) > > +{ > > + ARMCPU *cpu = ARM_CPU(obj); > > + > > + return cpu->has_pmu; > > +} > > + > > +static void arm_set_pmu(Object *obj, bool value, Error **errp) > > +{ > > + ARMCPU *cpu = ARM_CPU(obj); > > + > > + if (value) { > > + if (kvm_enabled() && !kvm_arm_pmu_supported(CPU(cpu))) { > > + error_setg(errp, "'pmu' feature not supported by KVM on this host"); > > + return; > > + } > > + set_feature(&cpu->env, ARM_FEATURE_PMU); > > + } else { > > + unset_feature(&cpu->env, ARM_FEATURE_PMU); > > + } > > + cpu->has_pmu = value; > > +} > > + > > static void arm_get_init_svtor(Object *obj, Visitor *v, const char *name, > > void *opaque, Error **errp) > > { > > @@ -859,7 +878,8 @@ void arm_cpu_post_init(Object *obj) > > } > > > > if (arm_feature(&cpu->env, ARM_FEATURE_PMU)) { > > - qdev_property_add_static(DEVICE(obj), &arm_cpu_has_pmu_property, > > + cpu->has_pmu = true; > > + object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu, > > &error_abort); > > This doesn't look right. > > The static property is only enabled here if the cpu is known to support the > PMU, and thus the only useful setting is -cpu foo,pmu=off. Which means that > the extra checking that you do in the dynamic property is unused. It's used when attempting to do '-cpu foo,pmu=on' on a cpu model that would support the PMU on TCG, and thus has the property, but won't work when KVM is in use. I'll admit I didn't test this, because I don't have 32-bit KVM hosts available, but I'm pretty sure it should work as expected: -accel tcg -cpu foo <-- on by default -accel tcg -cpu foo,pmu=off <-- off -accel tcg -cpu foo,pmu=on <-- nop -accel kvm -cpu foo <-- on by default if kvm+foo supports the pmu, otherwise off -accel kvm -cpu foo,pmu=off <-- off -accel kvm -cpu foo,pmu=on <-- nop if kvm+foo supports the pmu, otherwise error message With the error message, which will only occur with 32-bit kvm hosts, since 64-bit kvm hosts have all supported the pmu for quite some time, being the only new thing. > > It seems like you need to be checking for the PMU earlier, e.g. in > kvm_arm_get_host_cpu_features. We need to push all the checks into property accessors if we want the QMP command to work for them. Thanks, drew
diff --git a/target/arm/cpu.c b/target/arm/cpu.c index 376db154f008..858f668d226e 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -759,10 +759,6 @@ static Property arm_cpu_has_el3_property = static Property arm_cpu_cfgend_property = DEFINE_PROP_BOOL("cfgend", ARMCPU, cfgend, false); -/* use property name "pmu" to match other archs and virt tools */ -static Property arm_cpu_has_pmu_property = - DEFINE_PROP_BOOL("pmu", ARMCPU, has_pmu, true); - static Property arm_cpu_has_vfp_property = DEFINE_PROP_BOOL("vfp", ARMCPU, has_vfp, true); @@ -785,6 +781,29 @@ static Property arm_cpu_pmsav7_dregion_property = pmsav7_dregion, qdev_prop_uint32, uint32_t); +static bool arm_get_pmu(Object *obj, Error **errp) +{ + ARMCPU *cpu = ARM_CPU(obj); + + return cpu->has_pmu; +} + +static void arm_set_pmu(Object *obj, bool value, Error **errp) +{ + ARMCPU *cpu = ARM_CPU(obj); + + if (value) { + if (kvm_enabled() && !kvm_arm_pmu_supported(CPU(cpu))) { + error_setg(errp, "'pmu' feature not supported by KVM on this host"); + return; + } + set_feature(&cpu->env, ARM_FEATURE_PMU); + } else { + unset_feature(&cpu->env, ARM_FEATURE_PMU); + } + cpu->has_pmu = value; +} + static void arm_get_init_svtor(Object *obj, Visitor *v, const char *name, void *opaque, Error **errp) { @@ -859,7 +878,8 @@ void arm_cpu_post_init(Object *obj) } if (arm_feature(&cpu->env, ARM_FEATURE_PMU)) { - qdev_property_add_static(DEVICE(obj), &arm_cpu_has_pmu_property, + cpu->has_pmu = true; + object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu, &error_abort); } diff --git a/target/arm/kvm.c b/target/arm/kvm.c index fe4f461d4ef6..69c961a4c62c 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -162,6 +162,15 @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu) env->features = arm_host_cpu_features.features; } +bool kvm_arm_pmu_supported(CPUState *cpu) +{ + KVMState *s = KVM_STATE(current_machine->accelerator); + int ret; + + ret = kvm_check_extension(s, KVM_CAP_ARM_PMU_V3); + return ret > 0; +} + int kvm_arm_get_max_vm_ipa_size(MachineState *ms) { KVMState *s = KVM_STATE(ms->accelerator); diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h index 812125f805a1..e0ded3607996 100644 --- a/target/arm/kvm_arm.h +++ b/target/arm/kvm_arm.h @@ -216,6 +216,14 @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu); */ bool kvm_arm_aarch32_supported(CPUState *cs); +/** + * bool kvm_arm_pmu_supported: + * @cs: CPUState + * + * Returns true if the KVM VCPU can enable its PMU and false otherwise. + */ +bool kvm_arm_pmu_supported(CPUState *cs); + /** * kvm_arm_get_max_vm_ipa_size - Returns the number of bits in the * IPA address space supported by KVM @@ -261,6 +269,11 @@ static inline bool kvm_arm_aarch32_supported(CPUState *cs) return false; } +static inline bool kvm_arm_pmu_supported(CPUState *cs) +{ + return false; +} + static inline int kvm_arm_get_max_vm_ipa_size(MachineState *ms) { return -ENOENT;
We first convert the pmu property from a static property to one with its own accessors. Then we use the set accessor to check if the PMU is supported when using KVM. Indeed a 32-bit KVM host does not support the PMU, so this check will catch an attempt to use it at property-set time. Signed-off-by: Andrew Jones <drjones@redhat.com> --- target/arm/cpu.c | 30 +++++++++++++++++++++++++----- target/arm/kvm.c | 9 +++++++++ target/arm/kvm_arm.h | 13 +++++++++++++ 3 files changed, 47 insertions(+), 5 deletions(-)