diff options
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/guest.c | 139 |
1 files changed, 127 insertions, 12 deletions
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 756d0d614993..736d8cb8dad7 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -19,8 +19,11 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/bits.h> #include <linux/errno.h> #include <linux/err.h> +#include <linux/nospec.h> +#include <linux/kernel.h> #include <linux/kvm_host.h> #include <linux/module.h> #include <linux/stddef.h> @@ -30,9 +33,12 @@ #include <kvm/arm_psci.h> #include <asm/cputype.h> #include <linux/uaccess.h> +#include <asm/fpsimd.h> #include <asm/kvm.h> #include <asm/kvm_emulate.h> #include <asm/kvm_coproc.h> +#include <asm/kvm_host.h> +#include <asm/sigcontext.h> #include "trace.h" @@ -200,6 +206,115 @@ out: return err; } +#define SVE_REG_SLICE_SHIFT 0 +#define SVE_REG_SLICE_BITS 5 +#define SVE_REG_ID_SHIFT (SVE_REG_SLICE_SHIFT + SVE_REG_SLICE_BITS) +#define SVE_REG_ID_BITS 5 + +#define SVE_REG_SLICE_MASK \ + GENMASK(SVE_REG_SLICE_SHIFT + SVE_REG_SLICE_BITS - 1, \ + SVE_REG_SLICE_SHIFT) +#define SVE_REG_ID_MASK \ + GENMASK(SVE_REG_ID_SHIFT + SVE_REG_ID_BITS - 1, SVE_REG_ID_SHIFT) + +#define SVE_NUM_SLICES (1 << SVE_REG_SLICE_BITS) + +#define KVM_SVE_ZREG_SIZE KVM_REG_SIZE(KVM_REG_ARM64_SVE_ZREG(0, 0)) +#define KVM_SVE_PREG_SIZE KVM_REG_SIZE(KVM_REG_ARM64_SVE_PREG(0, 0)) + +/* Bounds of a single SVE register slice within vcpu->arch.sve_state */ +struct sve_state_reg_region { + unsigned int koffset; /* offset into sve_state in kernel memory */ + unsigned int klen; /* length in kernel memory */ + unsigned int upad; /* extra trailing padding in user memory */ +}; + +/* Get sanitised bounds for user/kernel SVE register copy */ +static int sve_reg_to_region(struct sve_state_reg_region *region, + struct kvm_vcpu *vcpu, + const struct kvm_one_reg *reg) +{ + /* reg ID ranges for Z- registers */ + const u64 zreg_id_min = KVM_REG_ARM64_SVE_ZREG(0, 0); + const u64 zreg_id_max = KVM_REG_ARM64_SVE_ZREG(SVE_NUM_ZREGS - 1, + SVE_NUM_SLICES - 1); + + /* reg ID ranges for P- registers and FFR (which are contiguous) */ + const u64 preg_id_min = KVM_REG_ARM64_SVE_PREG(0, 0); + const u64 preg_id_max = KVM_REG_ARM64_SVE_FFR(SVE_NUM_SLICES - 1); + + unsigned int vq; + unsigned int reg_num; + + unsigned int reqoffset, reqlen; /* User-requested offset and length */ + unsigned int maxlen; /* Maxmimum permitted length */ + + size_t sve_state_size; + + /* Only the first slice ever exists, for now: */ + if ((reg->id & SVE_REG_SLICE_MASK) != 0) + return -ENOENT; + + vq = sve_vq_from_vl(vcpu->arch.sve_max_vl); + + reg_num = (reg->id & SVE_REG_ID_MASK) >> SVE_REG_ID_SHIFT; + + if (reg->id >= zreg_id_min && reg->id <= zreg_id_max) { + reqoffset = SVE_SIG_ZREG_OFFSET(vq, reg_num) - + SVE_SIG_REGS_OFFSET; + reqlen = KVM_SVE_ZREG_SIZE; + maxlen = SVE_SIG_ZREG_SIZE(vq); + } else if (reg->id >= preg_id_min && reg->id <= preg_id_max) { + reqoffset = SVE_SIG_PREG_OFFSET(vq, reg_num) - + SVE_SIG_REGS_OFFSET; + reqlen = KVM_SVE_PREG_SIZE; + maxlen = SVE_SIG_PREG_SIZE(vq); + } else { + return -ENOENT; + } + + sve_state_size = vcpu_sve_state_size(vcpu); + if (!sve_state_size) + return -EINVAL; + + region->koffset = array_index_nospec(reqoffset, sve_state_size); + region->klen = min(maxlen, reqlen); + region->upad = reqlen - region->klen; + + return 0; +} + +static int get_sve_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) +{ + struct sve_state_reg_region region; + char __user *uptr = (char __user *)reg->addr; + + if (!vcpu_has_sve(vcpu) || sve_reg_to_region(®ion, vcpu, reg)) + return -ENOENT; + + if (copy_to_user(uptr, vcpu->arch.sve_state + region.koffset, + region.klen) || + clear_user(uptr + region.klen, region.upad)) + return -EFAULT; + + return 0; +} + +static int set_sve_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) +{ + struct sve_state_reg_region region; + const char __user *uptr = (const char __user *)reg->addr; + + if (!vcpu_has_sve(vcpu) || sve_reg_to_region(®ion, vcpu, reg)) + return -ENOENT; + + if (copy_from_user(vcpu->arch.sve_state + region.koffset, uptr, + region.klen)) + return -EFAULT; + + return 0; +} + int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) { return -EINVAL; @@ -346,12 +461,12 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32) return -EINVAL; - /* Register group 16 means we want a core register. */ - if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE) - return get_core_reg(vcpu, reg); - - if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW) - return kvm_arm_get_fw_reg(vcpu, reg); + switch (reg->id & KVM_REG_ARM_COPROC_MASK) { + case KVM_REG_ARM_CORE: return get_core_reg(vcpu, reg); + case KVM_REG_ARM_FW: return kvm_arm_get_fw_reg(vcpu, reg); + case KVM_REG_ARM64_SVE: return get_sve_reg(vcpu, reg); + default: break; /* fall through */ + } if (is_timer_reg(reg->id)) return get_timer_reg(vcpu, reg); @@ -365,12 +480,12 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32) return -EINVAL; - /* Register group 16 means we set a core register. */ - if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE) - return set_core_reg(vcpu, reg); - - if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW) - return kvm_arm_set_fw_reg(vcpu, reg); + switch (reg->id & KVM_REG_ARM_COPROC_MASK) { + case KVM_REG_ARM_CORE: return set_core_reg(vcpu, reg); + case KVM_REG_ARM_FW: return kvm_arm_set_fw_reg(vcpu, reg); + case KVM_REG_ARM64_SVE: return set_sve_reg(vcpu, reg); + default: break; /* fall through */ + } if (is_timer_reg(reg->id)) return set_timer_reg(vcpu, reg); 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