| Message ID | 20240209160039.677865-5-eric.auger@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | ARM Nested Virt Support | expand |
On Fri, 9 Feb 2024 at 16:00, Eric Auger <eric.auger@redhat.com> wrote: > > From: Haibo Xu <haibo.xu@linaro.org> > > KVM_CAP_ARM_EL2 must be supported by the cpu to enable ARM_FEATURE_EL2. > In case the host does support NV, expose the feature. > > Signed-off-by: Haibo Xu <haibo.xu@linaro.org> > Signed-off-by: Miguel Luis <miguel.luis@oracle.com> > Signed-off-by: Eric Auger <eric.auger@redhat.com> > > --- > > v1 -> v2: > - remove isar_feature_aa64_aa32_el2 modif in target/arm/cpu.h > [Richard] and use el2_supported in kvm_arch_init_vcpu > --- > target/arm/kvm.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/target/arm/kvm.c b/target/arm/kvm.c > index 0996866afe..a08bc68a3f 100644 > --- a/target/arm/kvm.c > +++ b/target/arm/kvm.c > @@ -238,6 +238,7 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) > */ > int fdarray[3]; > bool sve_supported; > + bool el2_supported; > bool pmu_supported = false; > uint64_t features = 0; > int err; > @@ -268,6 +269,14 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) > init.features[0] |= 1 << KVM_ARM_VCPU_SVE; > } > > + /* > + * Ask for EL2 if supported. > + */ > + el2_supported = kvm_arm_el2_supported(); > + if (el2_supported) { > + init.features[0] |= 1 << KVM_ARM_VCPU_HAS_EL2; > + } > + > /* > * Ask for Pointer Authentication if supported, so that we get > * the unsanitized field values for AA64ISAR1_EL1. > @@ -449,6 +458,10 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) > features |= 1ULL << ARM_FEATURE_PMU; > features |= 1ULL << ARM_FEATURE_GENERIC_TIMER; > > + if (el2_supported) { > + features |= 1ULL << ARM_FEATURE_EL2; > + } > + > ahcf->features = features; > > return true; > @@ -1912,6 +1925,9 @@ int kvm_arch_init_vcpu(CPUState *cs) > cpu->kvm_init_features[0] |= (1 << KVM_ARM_VCPU_PTRAUTH_ADDRESS | > 1 << KVM_ARM_VCPU_PTRAUTH_GENERIC); > } > + if (kvm_arm_el2_supported()) { > + cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_HAS_EL2; > + } > > /* Do KVM_ARM_VCPU_INIT ioctl */ > ret = kvm_arm_vcpu_init(cpu); Am I reading this right that if the kernel supports FEAT_NV then we will always ask for a vCPU with that feature? Is that a good idea, or should we arrange to only do it if the user uses the 'virtualization=on' option to -M virt ? (Or does that happen already in some way I'm not seeing?) thanks -- PMM
Hi Peter, On 3/5/24 17:49, Peter Maydell wrote: > On Fri, 9 Feb 2024 at 16:00, Eric Auger <eric.auger@redhat.com> wrote: >> From: Haibo Xu <haibo.xu@linaro.org> >> >> KVM_CAP_ARM_EL2 must be supported by the cpu to enable ARM_FEATURE_EL2. >> In case the host does support NV, expose the feature. >> >> Signed-off-by: Haibo Xu <haibo.xu@linaro.org> >> Signed-off-by: Miguel Luis <miguel.luis@oracle.com> >> Signed-off-by: Eric Auger <eric.auger@redhat.com> >> >> --- >> >> v1 -> v2: >> - remove isar_feature_aa64_aa32_el2 modif in target/arm/cpu.h >> [Richard] and use el2_supported in kvm_arch_init_vcpu >> --- >> target/arm/kvm.c | 16 ++++++++++++++++ >> 1 file changed, 16 insertions(+) >> >> diff --git a/target/arm/kvm.c b/target/arm/kvm.c >> index 0996866afe..a08bc68a3f 100644 >> --- a/target/arm/kvm.c >> +++ b/target/arm/kvm.c >> @@ -238,6 +238,7 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) >> */ >> int fdarray[3]; >> bool sve_supported; >> + bool el2_supported; >> bool pmu_supported = false; >> uint64_t features = 0; >> int err; >> @@ -268,6 +269,14 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) >> init.features[0] |= 1 << KVM_ARM_VCPU_SVE; >> } >> >> + /* >> + * Ask for EL2 if supported. >> + */ >> + el2_supported = kvm_arm_el2_supported(); >> + if (el2_supported) { >> + init.features[0] |= 1 << KVM_ARM_VCPU_HAS_EL2; >> + } >> + >> /* >> * Ask for Pointer Authentication if supported, so that we get >> * the unsanitized field values for AA64ISAR1_EL1. >> @@ -449,6 +458,10 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) >> features |= 1ULL << ARM_FEATURE_PMU; >> features |= 1ULL << ARM_FEATURE_GENERIC_TIMER; >> >> + if (el2_supported) { >> + features |= 1ULL << ARM_FEATURE_EL2; >> + } >> + >> ahcf->features = features; >> >> return true; >> @@ -1912,6 +1925,9 @@ int kvm_arch_init_vcpu(CPUState *cs) >> cpu->kvm_init_features[0] |= (1 << KVM_ARM_VCPU_PTRAUTH_ADDRESS | >> 1 << KVM_ARM_VCPU_PTRAUTH_GENERIC); >> } >> + if (kvm_arm_el2_supported()) { >> + cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_HAS_EL2; >> + } >> >> /* Do KVM_ARM_VCPU_INIT ioctl */ >> ret = kvm_arm_vcpu_init(cpu); > Am I reading this right that if the kernel supports FEAT_NV > then we will always ask for a vCPU with that feature? > Is that a good idea, or should we arrange to only do it if > the user uses the 'virtualization=on' option to -M virt ? > (Or does that happen already in some way I'm not seeing?) yes you're right, if the host supports it, the feature is currently set on the vcpu. I am not totaly clear under which conditions the features shall be instantiated in the scratch VM and when the host passthrough model shall be altered by machine option. Thanks Eric > > thanks > -- PMM >
diff --git a/target/arm/kvm.c b/target/arm/kvm.c index 0996866afe..a08bc68a3f 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -238,6 +238,7 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) */ int fdarray[3]; bool sve_supported; + bool el2_supported; bool pmu_supported = false; uint64_t features = 0; int err; @@ -268,6 +269,14 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) init.features[0] |= 1 << KVM_ARM_VCPU_SVE; } + /* + * Ask for EL2 if supported. + */ + el2_supported = kvm_arm_el2_supported(); + if (el2_supported) { + init.features[0] |= 1 << KVM_ARM_VCPU_HAS_EL2; + } + /* * Ask for Pointer Authentication if supported, so that we get * the unsanitized field values for AA64ISAR1_EL1. @@ -449,6 +458,10 @@ static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) features |= 1ULL << ARM_FEATURE_PMU; features |= 1ULL << ARM_FEATURE_GENERIC_TIMER; + if (el2_supported) { + features |= 1ULL << ARM_FEATURE_EL2; + } + ahcf->features = features; return true; @@ -1912,6 +1925,9 @@ int kvm_arch_init_vcpu(CPUState *cs) cpu->kvm_init_features[0] |= (1 << KVM_ARM_VCPU_PTRAUTH_ADDRESS | 1 << KVM_ARM_VCPU_PTRAUTH_GENERIC); } + if (kvm_arm_el2_supported()) { + cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_HAS_EL2; + } /* Do KVM_ARM_VCPU_INIT ioctl */ ret = kvm_arm_vcpu_init(cpu);