This patch adds --enable-sve/--disable-sve command line options to allow the user to control whether the Scalable Vector Extension is made available to the guest.
This requires use of the new KVM_ARM_VCPU_FINALIZE ioctl before the vcpu is runnable, so a new hook kvm_cpu__configure_features() is added to provide an appropriate place to do this work. By default, SVE is enabled for the guest if the host supports it. Signed-off-by: Dave Martin <[email protected]> --- arm/aarch32/include/kvm/kvm-cpu-arch.h | 4 +++ arm/aarch64/include/kvm/kvm-config-arch.h | 6 ++++- arm/aarch64/include/kvm/kvm-cpu-arch.h | 1 + arm/aarch64/kvm-cpu.c | 41 +++++++++++++++++++++++++++++++ arm/include/arm-common/kvm-config-arch.h | 2 ++ arm/kvm-cpu.c | 3 +++ 6 files changed, 56 insertions(+), 1 deletion(-) diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h index 01983f0..780e0e2 100644 --- a/arm/aarch32/include/kvm/kvm-cpu-arch.h +++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h @@ -15,5 +15,9 @@ static inline void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init) { } +static inline int kvm_cpu__configure_features(struct kvm_cpu *vcpu) +{ + return 0; +} #endif /* KVM__KVM_CPU_ARCH_H */ diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h index fe1699d..41e9d05 100644 --- a/arm/aarch64/include/kvm/kvm-config-arch.h +++ b/arm/aarch64/include/kvm/kvm-config-arch.h @@ -12,7 +12,11 @@ OPT_BOOLEAN('\0', "enable-ptrauth", &(cfg)->enable_ptrauth, \ "Enable pointer authentication for the guest"), \ OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth, \ - "Disable pointer authentication for the guest"), + "Disable pointer authentication for the guest"), \ + OPT_BOOLEAN('\0', "enable-sve", &(cfg)->enable_sve, \ + "Enable SVE for the guest"), \ + OPT_BOOLEAN('\0', "disable-sve", &(cfg)->disable_sve, \ + "Disable SVE for the guest"), #include "arm-common/kvm-config-arch.h" diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h index e6875fc..8dfb82e 100644 --- a/arm/aarch64/include/kvm/kvm-cpu-arch.h +++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h @@ -18,5 +18,6 @@ #define ARM_CPU_CTRL_SCTLR_EL1 0 void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init); +int kvm_cpu__configure_features(struct kvm_cpu *vcpu); #endif /* KVM__KVM_CPU_ARCH_H */ diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c index 08e4fd5..cdfb22e 100644 --- a/arm/aarch64/kvm-cpu.c +++ b/arm/aarch64/kvm-cpu.c @@ -152,9 +152,50 @@ static void select_ptrauth_feature(struct kvm *kvm, struct kvm_vcpu_init *init) } } +static void select_sve_feature(struct kvm *kvm, struct kvm_vcpu_init *init) +{ + bool supported; + + if (kvm->cfg.arch.enable_sve && kvm->cfg.arch.disable_sve) + die("--enable-sve conflicts with --disable-sve"); + + supported = kvm__supports_extension(kvm, KVM_CAP_ARM_SVE); + + if (kvm->cfg.arch.enable_sve && !supported) + die("--enable-sve not supported on this host"); + + /* Default SVE to on if available and not explicitly disabled */ + if (supported && !kvm->cfg.arch.disable_sve) { + kvm->cfg.arch.enable_sve = true; + init->features[0] |= 1UL << KVM_ARM_VCPU_SVE; + } +} + void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init) { select_ptrauth_feature(kvm, init); + select_sve_feature(kvm, init); +} + +static int configure_sve(struct kvm_cpu *vcpu) +{ + int feature = KVM_ARM_VCPU_SVE; + + if (ioctl(vcpu->vcpu_fd, KVM_ARM_VCPU_FINALIZE, &feature)) { + pr_err("KVM_ARM_VCPU_FINALIZE: %s", strerror(errno)); + return -1; + } + + return 0; +} + +int kvm_cpu__configure_features(struct kvm_cpu *vcpu) +{ + if (vcpu->kvm->cfg.arch.enable_sve) + if (configure_sve(vcpu)) + return -1; + + return 0; } void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu) diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h index 1b4287d..40e3d1f 100644 --- a/arm/include/arm-common/kvm-config-arch.h +++ b/arm/include/arm-common/kvm-config-arch.h @@ -10,6 +10,8 @@ struct kvm_config_arch { bool aarch32_guest; bool has_pmuv3; u64 kaslr_seed; + bool enable_sve; + bool disable_sve; bool enable_ptrauth; bool disable_ptrauth; enum irqchip_type irqchip; diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c index 1652f6f..554414f 100644 --- a/arm/kvm-cpu.c +++ b/arm/kvm-cpu.c @@ -124,6 +124,9 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) vcpu->cpu_compatible = target->compatible; vcpu->is_running = true; + if (kvm_cpu__configure_features(vcpu)) + die("Unable to configure requested vcpu features"); + return vcpu; } -- 2.1.4 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
