diff options
Diffstat (limited to 'arch/arm64/kvm/reset.c')
| -rw-r--r-- | arch/arm64/kvm/reset.c | 167 |
1 files changed, 166 insertions, 1 deletions
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index e2a0500cd7a2..1140b4485575 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -20,20 +20,26 @@ */ #include <linux/errno.h> +#include <linux/kernel.h> #include <linux/kvm_host.h> #include <linux/kvm.h> #include <linux/hw_breakpoint.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/types.h> #include <kvm/arm_arch_timer.h> #include <asm/cpufeature.h> #include <asm/cputype.h> +#include <asm/fpsimd.h> #include <asm/ptrace.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/kvm_coproc.h> #include <asm/kvm_emulate.h> #include <asm/kvm_mmu.h> +#include <asm/virt.h> /* Maximum phys_shift supported for any VM on this host */ static u32 kvm_ipa_limit; @@ -92,6 +98,14 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ARM_VM_IPA_SIZE: r = kvm_ipa_limit; break; + case KVM_CAP_ARM_SVE: + r = system_supports_sve(); + break; + case KVM_CAP_ARM_PTRAUTH_ADDRESS: + case KVM_CAP_ARM_PTRAUTH_GENERIC: + r = has_vhe() && system_supports_address_auth() && + system_supports_generic_auth(); + break; default: r = 0; } @@ -99,13 +113,148 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext) return r; } +unsigned int kvm_sve_max_vl; + +int kvm_arm_init_sve(void) +{ + if (system_supports_sve()) { + kvm_sve_max_vl = sve_max_virtualisable_vl; + + /* + * The get_sve_reg()/set_sve_reg() ioctl interface will need + * to be extended with multiple register slice support in + * order to support vector lengths greater than + * SVE_VL_ARCH_MAX: + */ + if (WARN_ON(kvm_sve_max_vl > SVE_VL_ARCH_MAX)) + kvm_sve_max_vl = SVE_VL_ARCH_MAX; + + /* + * Don't even try to make use of vector lengths that + * aren't available on all CPUs, for now: + */ + if (kvm_sve_max_vl < sve_max_vl) + pr_warn("KVM: SVE vector length for guests limited to %u bytes\n", + kvm_sve_max_vl); + } + + return 0; +} + +static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu) +{ + if (!system_supports_sve()) + return -EINVAL; + + /* Verify that KVM startup enforced this when SVE was detected: */ + if (WARN_ON(!has_vhe())) + return -EINVAL; + + vcpu->arch.sve_max_vl = kvm_sve_max_vl; + + /* + * Userspace can still customize the vector lengths by writing + * KVM_REG_ARM64_SVE_VLS. Allocation is deferred until + * kvm_arm_vcpu_finalize(), which freezes the configuration. + */ + vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SVE; + + return 0; +} + +/* + * Finalize vcpu's maximum SVE vector length, allocating + * vcpu->arch.sve_state as necessary. + */ +static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu) +{ + void *buf; + unsigned int vl; + + vl = vcpu->arch.sve_max_vl; + + /* + * Resposibility for these properties is shared between + * kvm_arm_init_arch_resources(), kvm_vcpu_enable_sve() and + * set_sve_vls(). Double-check here just to be sure: + */ + if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl || + vl > SVE_VL_ARCH_MAX)) + return -EIO; + + buf = kzalloc(SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl)), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + vcpu->arch.sve_state = buf; + vcpu->arch.flags |= KVM_ARM64_VCPU_SVE_FINALIZED; + return 0; +} + +int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature) +{ + switch (feature) { + case KVM_ARM_VCPU_SVE: + if (!vcpu_has_sve(vcpu)) + return -EINVAL; + + if (kvm_arm_vcpu_sve_finalized(vcpu)) + return -EPERM; + + return kvm_vcpu_finalize_sve(vcpu); + } + + return -EINVAL; +} + +bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) +{ + if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu)) + return false; + + return true; +} + +void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) +{ + kfree(vcpu->arch.sve_state); +} + +static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) +{ + if (vcpu_has_sve(vcpu)) + memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu)); +} + +static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu) +{ + /* Support ptrauth only if the system supports these capabilities. */ + if (!has_vhe()) + return -EINVAL; + + if (!system_supports_address_auth() || + !system_supports_generic_auth()) + return -EINVAL; + /* + * For now make sure that both address/generic pointer authentication + * features are requested by the userspace together. + */ + if (!test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || + !test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) + return -EINVAL; + + vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_PTRAUTH; + return 0; +} + /** * kvm_reset_vcpu - sets core registers and sys_regs to reset value * @vcpu: The VCPU pointer * * This function finds the right table above and sets the registers on * the virtual CPU struct to their architecturally defined reset - * values. + * values, except for registers whose reset is deferred until + * kvm_arm_vcpu_finalize(). * * Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT * ioctl or as part of handling a request issued by another VCPU in the PSCI @@ -131,6 +280,22 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) if (loaded) kvm_arch_vcpu_put(vcpu); + if (!kvm_arm_vcpu_sve_finalized(vcpu)) { + if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) { + ret = kvm_vcpu_enable_sve(vcpu); + if (ret) + goto out; + } + } else { + kvm_vcpu_reset_sve(vcpu); + } + + if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || + test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) { + if (kvm_vcpu_enable_ptrauth(vcpu)) + goto out; + } + switch (vcpu->arch.target) { default: if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { |