diff options
Diffstat (limited to 'target/arm')
| -rw-r--r-- | target/arm/cpu.c | 25 | ||||
| -rw-r--r-- | target/arm/cpu.h | 21 | ||||
| -rw-r--r-- | target/arm/cpu64.c | 356 | ||||
| -rw-r--r-- | target/arm/helper.c | 10 | ||||
| -rw-r--r-- | target/arm/kvm.c | 25 | ||||
| -rw-r--r-- | target/arm/kvm32.c | 6 | ||||
| -rw-r--r-- | target/arm/kvm64.c | 323 | ||||
| -rw-r--r-- | target/arm/kvm_arm.h | 39 | ||||
| -rw-r--r-- | target/arm/monitor.c | 158 | ||||
| -rw-r--r-- | target/arm/translate-vfp.inc.c | 5 |
10 files changed, 913 insertions, 55 deletions
diff --git a/target/arm/cpu.c b/target/arm/cpu.c index ab3e1a0361..7a4ac9339b 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -200,7 +200,8 @@ static void arm_cpu_reset(CPUState *s) env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 16, 2, 3); env->cp15.cptr_el[3] |= CPTR_EZ; /* with maximum vector length */ - env->vfp.zcr_el[1] = cpu->sve_max_vq - 1; + env->vfp.zcr_el[1] = cpu_isar_feature(aa64_sve, cpu) ? + cpu->sve_max_vq - 1 : 0; env->vfp.zcr_el[2] = env->vfp.zcr_el[1]; env->vfp.zcr_el[3] = env->vfp.zcr_el[1]; /* @@ -1197,6 +1198,19 @@ static void arm_cpu_finalizefn(Object *obj) #endif } +void arm_cpu_finalize_features(ARMCPU *cpu, Error **errp) +{ + Error *local_err = NULL; + + if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) { + arm_cpu_sve_finalize(cpu, &local_err); + if (local_err != NULL) { + error_propagate(errp, local_err); + return; + } + } +} + static void arm_cpu_realizefn(DeviceState *dev, Error **errp) { CPUState *cs = CPU(dev); @@ -1253,6 +1267,12 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) return; } + arm_cpu_finalize_features(cpu, &local_err); + if (local_err != NULL) { + error_propagate(errp, local_err); + return; + } + if (arm_feature(env, ARM_FEATURE_AARCH64) && cpu->has_vfp != cpu->has_neon) { /* @@ -2650,6 +2670,9 @@ static void arm_host_initfn(Object *obj) ARMCPU *cpu = ARM_CPU(obj); kvm_arm_set_cpu_features_from_host(cpu); + if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) { + aarch64_add_sve_properties(obj); + } arm_cpu_post_init(obj); } diff --git a/target/arm/cpu.h b/target/arm/cpu.h index d844ea21d8..e1a66a2d1c 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -184,8 +184,13 @@ typedef struct { #ifdef TARGET_AARCH64 # define ARM_MAX_VQ 16 +void arm_cpu_sve_finalize(ARMCPU *cpu, Error **errp); +uint32_t arm_cpu_vq_map_next_smaller(ARMCPU *cpu, uint32_t vq); #else # define ARM_MAX_VQ 1 +static inline void arm_cpu_sve_finalize(ARMCPU *cpu, Error **errp) { } +static inline uint32_t arm_cpu_vq_map_next_smaller(ARMCPU *cpu, uint32_t vq) +{ return 0; } #endif typedef struct ARMVectorReg { @@ -918,6 +923,18 @@ struct ARMCPU { /* Used to set the maximum vector length the cpu will support. */ uint32_t sve_max_vq; + + /* + * In sve_vq_map each set bit is a supported vector length of + * (bit-number + 1) * 16 bytes, i.e. each bit number + 1 is the vector + * length in quadwords. + * + * While processing properties during initialization, corresponding + * sve_vq_init bits are set for bits in sve_vq_map that have been + * set by properties. + */ + DECLARE_BITMAP(sve_vq_map, ARM_MAX_VQ); + DECLARE_BITMAP(sve_vq_init, ARM_MAX_VQ); }; void arm_cpu_post_init(Object *obj); @@ -960,11 +977,13 @@ int aarch64_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg); void aarch64_sve_narrow_vq(CPUARMState *env, unsigned vq); void aarch64_sve_change_el(CPUARMState *env, int old_el, int new_el, bool el0_a64); +void aarch64_add_sve_properties(Object *obj); #else static inline void aarch64_sve_narrow_vq(CPUARMState *env, unsigned vq) { } static inline void aarch64_sve_change_el(CPUARMState *env, int o, int n, bool a) { } +static inline void aarch64_add_sve_properties(Object *obj) { } #endif #if !defined(CONFIG_TCG) @@ -1837,6 +1856,8 @@ static inline int arm_feature(CPUARMState *env, int feature) return (env->features & (1ULL << feature)) != 0; } +void arm_cpu_finalize_features(ARMCPU *cpu, Error **errp); + #if !defined(CONFIG_USER_ONLY) /* Return true if exception levels below EL3 are in secure state, * or would be following an exception return to that level. diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c index d7f5bf610a..68baf0482f 100644 --- a/target/arm/cpu64.c +++ b/target/arm/cpu64.c @@ -256,27 +256,357 @@ static void aarch64_a72_initfn(Object *obj) define_arm_cp_regs(cpu, cortex_a72_a57_a53_cp_reginfo); } -static void cpu_max_get_sve_vq(Object *obj, Visitor *v, const char *name, +void arm_cpu_sve_finalize(ARMCPU *cpu, Error **errp) +{ + /* + * If any vector lengths are explicitly enabled with sve<N> properties, + * then all other lengths are implicitly disabled. If sve-max-vq is + * specified then it is the same as explicitly enabling all lengths + * up to and including the specified maximum, which means all larger + * lengths will be implicitly disabled. If no sve<N> properties + * are enabled and sve-max-vq is not specified, then all lengths not + * explicitly disabled will be enabled. Additionally, all power-of-two + * vector lengths less than the maximum enabled length will be + * automatically enabled and all vector lengths larger than the largest + * disabled power-of-two vector length will be automatically disabled. + * Errors are generated if the user provided input that interferes with + * any of the above. Finally, if SVE is not disabled, then at least one + * vector length must be enabled. + */ + DECLARE_BITMAP(kvm_supported, ARM_MAX_VQ); + DECLARE_BITMAP(tmp, ARM_MAX_VQ); + uint32_t vq, max_vq = 0; + + /* Collect the set of vector lengths supported by KVM. */ + bitmap_zero(kvm_supported, ARM_MAX_VQ); + if (kvm_enabled() && kvm_arm_sve_supported(CPU(cpu))) { + kvm_arm_sve_get_vls(CPU(cpu), kvm_supported); + } else if (kvm_enabled()) { + assert(!cpu_isar_feature(aa64_sve, cpu)); + } + + /* + * Process explicit sve<N> properties. + * From the properties, sve_vq_map<N> implies sve_vq_init<N>. + * Check first for any sve<N> enabled. + */ + if (!bitmap_empty(cpu->sve_vq_map, ARM_MAX_VQ)) { + max_vq = find_last_bit(cpu->sve_vq_map, ARM_MAX_VQ) + 1; + + if (cpu->sve_max_vq && max_vq > cpu->sve_max_vq) { + error_setg(errp, "cannot enable sve%d", max_vq * 128); + error_append_hint(errp, "sve%d is larger than the maximum vector " + "length, sve-max-vq=%d (%d bits)\n", + max_vq * 128, cpu->sve_max_vq, + cpu->sve_max_vq * 128); + return; + } + + if (kvm_enabled()) { + /* + * For KVM we have to automatically enable all supported unitialized + * lengths, even when the smaller lengths are not all powers-of-two. + */ + bitmap_andnot(tmp, kvm_supported, cpu->sve_vq_init, max_vq); + bitmap_or(cpu->sve_vq_map, cpu->sve_vq_map, tmp, max_vq); + } else { + /* Propagate enabled bits down through required powers-of-two. */ + for (vq = pow2floor(max_vq); vq >= 1; vq >>= 1) { + if (!test_bit(vq - 1, cpu->sve_vq_init)) { + set_bit(vq - 1, cpu->sve_vq_map); + } + } + } + } else if (cpu->sve_max_vq == 0) { + /* + * No explicit bits enabled, and no implicit bits from sve-max-vq. + */ + if (!cpu_isar_feature(aa64_sve, cpu)) { + /* SVE is disabled and so are all vector lengths. Good. */ + return; + } + + if (kvm_enabled()) { + /* Disabling a supported length disables all larger lengths. */ + for (vq = 1; vq <= ARM_MAX_VQ; ++vq) { + if (test_bit(vq - 1, cpu->sve_vq_init) && + test_bit(vq - 1, kvm_supported)) { + break; + } + } + max_vq = vq <= ARM_MAX_VQ ? vq - 1 : ARM_MAX_VQ; + bitmap_andnot(cpu->sve_vq_map, kvm_supported, + cpu->sve_vq_init, max_vq); + if (max_vq == 0 || bitmap_empty(cpu->sve_vq_map, max_vq)) { + error_setg(errp, "cannot disable sve%d", vq * 128); + error_append_hint(errp, "Disabling sve%d results in all " + "vector lengths being disabled.\n", + vq * 128); + error_append_hint(errp, "With SVE enabled, at least one " + "vector length must be enabled.\n"); + return; + } + } else { + /* Disabling a power-of-two disables all larger lengths. */ + if (test_bit(0, cpu->sve_vq_init)) { + error_setg(errp, "cannot disable sve128"); + error_append_hint(errp, "Disabling sve128 results in all " + "vector lengths being disabled.\n"); + error_append_hint(errp, "With SVE enabled, at least one " + "vector length must be enabled.\n"); + return; + } + for (vq = 2; vq <= ARM_MAX_VQ; vq <<= 1) { + if (test_bit(vq - 1, cpu->sve_vq_init)) { + break; + } + } + max_vq = vq <= ARM_MAX_VQ ? vq - 1 : ARM_MAX_VQ; + bitmap_complement(cpu->sve_vq_map, cpu->sve_vq_init, max_vq); + } + + max_vq = find_last_bit(cpu->sve_vq_map, max_vq) + 1; + } + + /* + * Process the sve-max-vq property. + * Note that we know from the above that no bit above + * sve-max-vq is currently set. + */ + if (cpu->sve_max_vq != 0) { + max_vq = cpu->sve_max_vq; + + if (!test_bit(max_vq - 1, cpu->sve_vq_map) && + test_bit(max_vq - 1, cpu->sve_vq_init)) { + error_setg(errp, "cannot disable sve%d", max_vq * 128); + error_append_hint(errp, "The maximum vector length must be " + "enabled, sve-max-vq=%d (%d bits)\n", + max_vq, max_vq * 128); + return; + } + + /* Set all bits not explicitly set within sve-max-vq. */ + bitmap_complement(tmp, cpu->sve_vq_init, max_vq); + bitmap_or(cpu->sve_vq_map, cpu->sve_vq_map, tmp, max_vq); + } + + /* + * We should know what max-vq is now. Also, as we're done + * manipulating sve-vq-map, we ensure any bits above max-vq + * are clear, just in case anybody looks. + */ + assert(max_vq != 0); + bitmap_clear(cpu->sve_vq_map, max_vq, ARM_MAX_VQ - max_vq); + + if (kvm_enabled()) { + /* Ensure the set of lengths matches what KVM supports. */ + bitmap_xor(tmp, cpu->sve_vq_map, kvm_supported, max_vq); + if (!bitmap_empty(tmp, max_vq)) { + vq = find_last_bit(tmp, max_vq) + 1; + if (test_bit(vq - 1, cpu->sve_vq_map)) { + if (cpu->sve_max_vq) { + error_setg(errp, "cannot set sve-max-vq=%d", + cpu->sve_max_vq); + error_append_hint(errp, "This KVM host does not support " + "the vector length %d-bits.\n", + vq * 128); + error_append_hint(errp, "It may not be possible to use " + "sve-max-vq with this KVM host. Try " + "using only sve<N> properties.\n"); + } else { + error_setg(errp, "cannot enable sve%d", vq * 128); + error_append_hint(errp, "This KVM host does not support " + "the vector length %d-bits.\n", + vq * 128); + } + } else { + error_setg(errp, "cannot disable sve%d", vq * 128); + error_append_hint(errp, "The KVM host requires all " + "supported vector lengths smaller " + "than %d bits to also be enabled.\n", + max_vq * 128); + } + return; + } + } else { + /* Ensure all required powers-of-two are enabled. */ + for (vq = pow2floor(max_vq); vq >= 1; vq >>= 1) { + if (!test_bit(vq - 1, cpu->sve_vq_map)) { + error_setg(errp, "cannot disable sve%d", vq * 128); + error_append_hint(errp, "sve%d is required as it " + "is a power-of-two length smaller than " + "the maximum, sve%d\n", + vq * 128, max_vq * 128); + return; + } + } + } + + /* + * Now that we validated all our vector lengths, the only question + * left to answer is if we even want SVE at all. + */ + if (!cpu_isar_feature(aa64_sve, cpu)) { + error_setg(errp, "cannot enable sve%d", max_vq * 128); + error_append_hint(errp, "SVE must be enabled to enable vector " + "lengths.\n"); + error_append_hint(errp, "Add sve=on to the CPU property list.\n"); + return; + } + + /* From now on sve_max_vq is the actual maximum supported length. */ + cpu->sve_max_vq = max_vq; +} + +uint32_t arm_cpu_vq_map_next_smaller(ARMCPU *cpu, uint32_t vq) +{ + uint32_t bitnum; + + /* + * We allow vq == ARM_MAX_VQ + 1 to be input because the caller may want + * to find the maximum vq enabled, which may be ARM_MAX_VQ, but this + * function always returns the next smaller than the input. + */ + assert(vq && vq <= ARM_MAX_VQ + 1); + + bitnum = find_last_bit(cpu->sve_vq_map, vq - 1); + return bitnum == vq - 1 ? 0 : bitnum + 1; +} + +static void cpu_max_get_sve_max_vq(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + ARMCPU *cpu = ARM_CPU(obj); + uint32_t value; + + /* All vector lengths are disabled when SVE is off. */ + if (!cpu_isar_feature(aa64_sve, cpu)) { + value = 0; + } else { + value = cpu->sve_max_vq; + } + visit_type_uint32(v, name, &value, errp); +} + +static void cpu_max_set_sve_max_vq(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + ARMCPU *cpu = ARM_CPU(obj); + Error *err = NULL; + uint32_t max_vq; + + visit_type_uint32(v, name, &max_vq, &err); + if (err) { + error_propagate(errp, err); + return; + } + + if (kvm_enabled() && !kvm_arm_sve_supported(CPU(cpu))) { + error_setg(errp, "cannot set sve-max-vq"); + error_append_hint(errp, "SVE not supported by KVM on this host\n"); + return; + } + + if (max_vq == 0 || max_vq > ARM_MAX_VQ) { + error_setg(errp, "unsupported SVE vector length"); + error_append_hint(errp, "Valid sve-max-vq in range [1-%d]\n", + ARM_MAX_VQ); + return; + } + + cpu->sve_max_vq = max_vq; +} + +static void cpu_arm_get_sve_vq(Object *obj, Visitor *v, const char *name, void *opaque, Error **errp) { ARMCPU *cpu = ARM_CPU(obj); - visit_type_uint32(v, name, &cpu->sve_max_vq, errp); + uint32_t vq = atoi(&name[3]) / 128; + bool value; + + /* All vector lengths are disabled when SVE is off. */ + if (!cpu_isar_feature(aa64_sve, cpu)) { + value = false; + } else { + value = test_bit(vq - 1, cpu->sve_vq_map); + } + visit_type_bool(v, name, &value, errp); } -static void cpu_max_set_sve_vq(Object *obj, Visitor *v, const char *name, +static void cpu_arm_set_sve_vq(Object *obj, Visitor *v, const char *name, void *opaque, Error **errp) { ARMCPU *cpu = ARM_CPU(obj); + uint32_t vq = atoi(&name[3]) / 128; Error *err = NULL; + bool value; - visit_type_uint32(v, name, &cpu->sve_max_vq, &err); + visit_type_bool(v, name, &value, &err); + if (err) { + error_propagate(errp, err); + return; + } - if (!err && (cpu->sve_max_vq == 0 || cpu->sve_max_vq > ARM_MAX_VQ)) { - error_setg(&err, "unsupported SVE vector length"); - error_append_hint(&err, "Valid sve-max-vq in range [1-%d]\n", - ARM_MAX_VQ); + if (value && kvm_enabled() && !kvm_arm_sve_supported(CPU(cpu))) { + error_setg(errp, "cannot enable %s", name); + error_append_hint(errp, "SVE not supported by KVM on this host\n"); + return; + } + + if (value) { + set_bit(vq - 1, cpu->sve_vq_map); + } else { + clear_bit(vq - 1, cpu->sve_vq_map); + } + set_bit(vq - 1, cpu->sve_vq_init); +} + +static void cpu_arm_get_sve(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + ARMCPU *cpu = ARM_CPU(obj); + bool value = cpu_isar_feature(aa64_sve, cpu); + + visit_type_bool(v, name, &value, errp); +} + +static void cpu_arm_set_sve(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + ARMCPU *cpu = ARM_CPU(obj); + Error *err = NULL; + bool value; + uint64_t t; + + visit_type_bool(v, name, &value, &err); + if (err) { + error_propagate(errp, err); + return; + } + + if (value && kvm_enabled() && !kvm_arm_sve_supported(CPU(cpu))) { + error_setg(errp, "'sve' feature not supported by KVM on this host"); + return; + } + + t = cpu->isar.id_aa64pfr0; + t = FIELD_DP64(t, ID_AA64PFR0, SVE, value); + cpu->isar.id_aa64pfr0 = t; +} + +void aarch64_add_sve_properties(Object *obj) +{ + uint32_t vq; + + object_property_add(obj, "sve", "bool", cpu_arm_get_sve, + cpu_arm_set_sve, NULL, NULL, &error_fatal); + + for (vq = 1; vq <= ARM_MAX_VQ; ++vq) { + char name[8]; + sprintf(name, "sve%d", vq * 128); + object_property_add(obj, name, "bool", cpu_arm_get_sve_vq, + cpu_arm_set_sve_vq, NULL, NULL, &error_fatal); } - error_propagate(errp, err); } /* -cpu max: if KVM is enabled, like -cpu host (best possible with this host); @@ -389,11 +719,11 @@ static void aarch64_max_initfn(Object *obj) cpu->ctr = 0x80038003; /* 32 byte I and D cacheline size, VIPT icache */ cpu->dcz_blocksize = 7; /* 512 bytes */ #endif - - cpu->sve_max_vq = ARM_MAX_VQ; - object_property_add(obj, "sve-max-vq", "uint32", cpu_max_get_sve_vq, - cpu_max_set_sve_vq, NULL, NULL, &error_fatal); } + + aarch64_add_sve_properties(obj); + object_property_add(obj, "sve-max-vq", "uint32", cpu_max_get_sve_max_vq, + cpu_max_set_sve_max_vq, NULL, NULL, &error_fatal); } struct ARMCPUInfo { diff --git a/target/arm/helper.c b/target/arm/helper.c index 63815fc4cf..be67e2c66d 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -5361,6 +5361,13 @@ int sve_exception_el(CPUARMState *env, int el) return 0; } +static uint32_t sve_zcr_get_valid_len(ARMCPU *cpu, uint32_t start_len) +{ + uint32_t start_vq = (start_len & 0xf) + 1; + + return arm_cpu_vq_map_next_smaller(cpu, start_vq + 1) - 1; +} + /* * Given that SVE is enabled, return the vector length for EL. */ @@ -5378,7 +5385,8 @@ uint32_t sve_zcr_len_for_el(CPUARMState *env, int el) if (arm_feature(env, ARM_FEATURE_EL3)) { zcr_len = MIN(zcr_len, 0xf & (uint32_t)env->vfp.zcr_el[3]); } - return zcr_len; + + return sve_zcr_get_valid_len(cpu, zcr_len); } static void zcr_write(CPUARMState *env, const ARMCPRegInfo *ri, diff --git a/target/arm/kvm.c b/target/arm/kvm.c index b473c63edb..5b82cefef6 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -51,6 +51,11 @@ int kvm_arm_vcpu_init(CPUState *cs) return kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init); } +int kvm_arm_vcpu_finalize(CPUState *cs, int feature) +{ + return kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_FINALIZE, &feature); +} + void kvm_arm_init_serror_injection(CPUState *cs) { cap_has_inject_serror_esr = kvm_check_extension(cs->kvm_state, @@ -61,7 +66,7 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try, int *fdarray, struct kvm_vcpu_init *init) { - int ret, kvmfd = -1, vmfd = -1, cpufd = -1; + int ret = 0, kvmfd = -1, vmfd = -1, cpufd = -1; kvmfd = qemu_open("/dev/kvm", O_RDWR); if (kvmfd < 0) { @@ -81,7 +86,14 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try, goto finish; } - ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, init); + if (init->target == -1) { + struct kvm_vcpu_init preferred; + + ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, &preferred); + if (!ret) { + init->target = preferred.target; + } + } if (ret >= 0) { ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init); if (ret < 0) { @@ -93,10 +105,12 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try, * creating one kind of guest CPU which is its preferred * CPU type. */ + struct kvm_vcpu_init try; + while (*cpus_to_try != QEMU_KVM_ARM_TARGET_NONE) { - init->target = *cpus_to_try++; - memset(init->features, 0, sizeof(init->features)); - ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init); + try.target = *cpus_to_try++; + memcpy(try.features, init->features, sizeof(init->features)); + ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, &try); if (ret >= 0) { break; } @@ -104,6 +118,7 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try, if (ret < 0) { goto err; } + init->target = try.target; } else { /* Treat a NULL cpus_to_try argument the same as an empty * list, which means we will fail the call since this must diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c index 2451a2d4bb..32bf8d6757 100644 --- a/target/arm/kvm32.c +++ b/target/arm/kvm32.c @@ -53,7 +53,11 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) QEMU_KVM_ARM_TARGET_CORTEX_A15, QEMU_KVM_ARM_TARGET_NONE }; - struct kvm_vcpu_init init; + /* + * target = -1 informs kvm_arm_create_scratch_host_vcpu() + * to use the preferred target + */ + struct kvm_vcpu_init init = { .target = -1, }; if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) { return false; diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c index 28f6db57d5..876184b8fe 100644 --- a/target/arm/kvm64.c +++ b/target/arm/kvm64.c @@ -488,7 +488,9 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) * and then query that CPU for the relevant ID registers. */ int fdarray[3]; + bool sve_supported; uint64_t features = 0; + uint64_t t; int err; /* Old kernels may not know about the PREFERRED_TARGET ioctl: however @@ -502,7 +504,11 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) KVM_ARM_TARGET_CORTEX_A57, QEMU_KVM_ARM_TARGET_NONE }; - struct kvm_vcpu_init init; + /* + * target = -1 informs kvm_arm_create_scratch_host_vcpu() + * to use the preferred target + */ + struct kvm_vcpu_init init = { .target = -1, }; if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) { return false; @@ -574,13 +580,23 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) ARM64_SYS_REG(3, 0, 0, 3, 2)); } + sve_supported = ioctl(fdarray[0], KVM_CHECK_EXTENSION, KVM_CAP_ARM_SVE) > 0; + kvm_arm_destroy_scratch_host_vcpu(fdarray); if (err < 0) { return false; } - /* We can assume any KVM supporting CPU is at least a v8 + /* Add feature bits that can't appear until after VCPU init. */ + if (sve_supported) { + t = ahcf->isar.id_aa64pfr0; + t = FIELD_DP64(t, ID_AA64PFR0, SVE, 1); + ahcf->isar.id_aa64pfr0 = t; + } + + /* + * We can assume any KVM supporting CPU is at least a v8 * with VFPv4+Neon; this in turn implies most of the other * feature bits. */ @@ -602,6 +618,107 @@ bool kvm_arm_aarch32_supported(CPUState *cpu) return kvm_check_extension(s, KVM_CAP_ARM_EL1_32BIT); } +bool kvm_arm_sve_supported(CPUState *cpu) +{ + KVMState *s = KVM_STATE(current_machine->accelerator); + + return kvm_check_extension(s, KVM_CAP_ARM_SVE); +} + +QEMU_BUILD_BUG_ON(KVM_ARM64_SVE_VQ_MIN != 1); + +void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map) +{ + /* Only call this function if kvm_arm_sve_supported() returns true. */ + static uint64_t vls[KVM_ARM64_SVE_VLS_WORDS]; + static bool probed; + uint32_t vq = 0; + int i, j; + + bitmap_clear(map, 0, ARM_MAX_VQ); + + /* + * KVM ensures all host CPUs support the same set of vector lengths. + * So we only need to create the scratch VCPUs once and then cache + * the results. + */ + if (!probed) { + struct kvm_vcpu_init init = { + .target = -1, + .features[0] = (1 << KVM_ARM_VCPU_SVE), + }; + struct kvm_one_reg reg = { + .id = KVM_REG_ARM64_SVE_VLS, + .addr = (uint64_t)&vls[0], + }; + int fdarray[3], ret; + + probed = true; + + if (!kvm_arm_create_scratch_host_vcpu(NULL, fdarray, &init)) { + error_report("failed to create scratch VCPU with SVE enabled"); + abort(); + } + ret = ioctl(fdarray[2], KVM_GET_ONE_REG, ®); + kvm_arm_destroy_scratch_host_vcpu(fdarray); + if (ret) { + error_report("failed to get KVM_REG_ARM64_SVE_VLS: %s", + strerror(errno)); + abort(); + } + + for (i = KVM_ARM64_SVE_VLS_WORDS - 1; i >= 0; --i) { + if (vls[i]) { + vq = 64 - clz64(vls[i]) + i * 64; + break; + } + } + if (vq > ARM_MAX_VQ) { + warn_report("KVM supports vector lengths larger than " + "QEMU can enable"); + } + } + + for (i = 0; i < KVM_ARM64_SVE_VLS_WORDS; ++i) { + if (!vls[i]) { + continue; + } + for (j = 1; j <= 64; ++j) { + vq = j + i * 64; + if (vq > ARM_MAX_VQ) { + return; + } + if (vls[i] & (1UL << (j - 1))) { + set_bit(vq - 1, map); + } + } + } +} + +static int kvm_arm_sve_set_vls(CPUState *cs) +{ + uint64_t vls[KVM_ARM64_SVE_VLS_WORDS] = {0}; + struct kvm_one_reg reg = { + .id = KVM_REG_ARM64_SVE_VLS, + .addr = (uint64_t)&vls[0], + }; + ARMCPU *cpu = ARM_CPU(cs); + uint32_t vq; + int i, j; + + assert(cpu->sve_max_vq <= KVM_ARM64_SVE_VQ_MAX); + + for (vq = 1; vq <= cpu->sve_max_vq; ++vq) { + if (test_bit(vq - 1, cpu->sve_vq_map)) { + i = (vq - 1) / 64; + j = (vq - 1) % 64; + vls[i] |= 1UL << j; + } + } + + return kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); +} + #define ARM_CPU_ID_MPIDR 3, 0, 0, 0, 5 int kvm_arch_init_vcpu(CPUState *cs) @@ -613,7 +730,7 @@ int kvm_arch_init_vcpu(CPUState *cs) if (cpu->kvm_target == QEMU_KVM_ARM_TARGET_NONE || !object_dynamic_cast(OBJECT(cpu), TYPE_AARCH64_CPU)) { - fprintf(stderr, "KVM is not supported for this guest CPU type\n"); + error_report("KVM is not supported for this guest CPU type"); return -EINVAL; } @@ -630,13 +747,17 @@ int kvm_arch_init_vcpu(CPUState *cs) cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_EL1_32BIT; } if (!kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PMU_V3)) { - cpu->has_pmu = false; + cpu->has_pmu = false; } if (cpu->has_pmu) { cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_PMU_V3; } else { unset_feature(&env->features, ARM_FEATURE_PMU); } + if (cpu_isar_feature(aa64_sve, cpu)) { + assert(kvm_arm_sve_supported(cs)); + cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_SVE; + } /* Do KVM_ARM_VCPU_INIT ioctl */ ret = kvm_arm_vcpu_init(cs); @@ -644,6 +765,17 @@ int kvm_arch_init_vcpu(CPUState *cs) return ret; } + if (cpu_isar_feature(aa64_sve, cpu)) { + ret = kvm_arm_sve_set_vls(cs); + if (ret) { + return ret; + } + ret = kvm_arm_vcpu_finalize(cs, KVM_ARM_VCPU_SVE); + if (ret) { + return ret; + } + } + /* * When KVM is in use, PSCI is emulated in-kernel and not by qemu. * Currently KVM has its own idea about MPIDR assignment, so we @@ -671,11 +803,12 @@ int kvm_arch_destroy_vcpu(CPUState *cs) bool kvm_arm_reg_syncs_via_cpreg_list(uint64_t regidx) { /* Return true if the regidx is a register we should synchronize - * via the cpreg_tuples array (ie is not a core reg we sync by - * hand in kvm_arch_get/put_registers()) + * via the cpreg_tuples array (ie is not a core or sve reg that + * we sync by hand in kvm_arch_get/put_registers()) */ switch (regidx & KVM_REG_ARM_COPROC_MASK) { case KVM_REG_ARM_CORE: + case KVM_REG_ARM64_SVE: return false; default: return true; @@ -721,10 +854,8 @@ int kvm_arm_cpreg_level(uint64_t regidx) static int kvm_arch_put_fpsimd(CPUState *cs) { - ARMCPU *cpu = ARM_CPU(cs); - CPUARMState *env = &cpu->env; + CPUARMState *env = &ARM_CPU(cs)->env; struct kvm_one_reg reg; - uint32_t fpr; int i, ret; for (i = 0; i < 32; i++) { @@ -742,17 +873,73 @@ static int kvm_arch_put_fpsimd(CPUState *cs) } } - reg.addr = (uintptr_t)(&fpr); - fpr = vfp_get_fpsr(env); - reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpsr); - ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); - if (ret) { - return ret; + return 0; +} + +/* + * SVE registers are encoded in KVM's memory in an endianness-invariant format. + * The byte at offset i from the start of the in-memory representation contains + * the bits [(7 + 8 * i) : (8 * i)] of the register value. As this means the + * lowest offsets are stored in the lowest memory addresses, then that nearly + * matches QEMU's representation, which is to use an array of host-endian + * uint64_t's, where the lower offsets are at the lower indices. To complete + * the translation we just need to byte swap the uint64_t's on big-endian hosts. + */ +static uint64_t *sve_bswap64(uint64_t *dst, uint64_t *src, int nr) +{ +#ifdef HOST_WORDS_BIGENDIAN + int i; + + for (i = 0; i < nr; ++i) { + dst[i] = bswap64(src[i]); } - reg.addr = (uintptr_t)(&fpr); - fpr = vfp_get_fpcr(env); - reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpcr); + return dst; +#else + return src; +#endif +} + +/* + * KVM SVE registers come in slices where ZREGs have a slice size of 2048 bits + * and PREGS and the FFR have a slice size of 256 bits. However we simply hard + * code the slice index to zero for now as it's unlikely we'll need more than + * one slice for quite some time. + */ +static int kvm_arch_put_sve(CPUState *cs) +{ + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + uint64_t tmp[ARM_MAX_VQ * 2]; + uint64_t *r; + struct kvm_one_reg reg; + int n, ret; + + for (n = 0; n < KVM_ARM64_SVE_NUM_ZREGS; ++n) { + r = sve_bswap64(tmp, &env->vfp.zregs[n].d[0], cpu->sve_max_vq * 2); + reg.addr = (uintptr_t)r; + reg.id = KVM_REG_ARM64_SVE_ZREG(n, 0); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret) { + return ret; + } + } + + for (n = 0; n < KVM_ARM64_SVE_NUM_PREGS; ++n) { + r = sve_bswap64(tmp, r = &env->vfp.pregs[n].p[0], + DIV_ROUND_UP(cpu->sve_max_vq * 2, 8)); + reg.addr = (uintptr_t)r; + reg.id = KVM_REG_ARM64_SVE_PREG(n, 0); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret) { + return ret; + } + } + + r = sve_bswap64(tmp, &env->vfp.pregs[FFR_PRED_NUM].p[0], + DIV_ROUND_UP(cpu->sve_max_vq * 2, 8)); + reg.addr = (uintptr_t)r; + reg.id = KVM_REG_ARM64_SVE_FFR(0); ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); if (ret) { return ret; @@ -765,6 +952,7 @@ int kvm_arch_put_registers(CPUState *cs, int level) { struct kvm_one_reg reg; uint64_t val; + uint32_t fpr; int i, ret; unsigned int el; @@ -855,7 +1043,27 @@ int kvm_arch_put_registers(CPUState *cs, int level) } } - ret = kvm_arch_put_fpsimd(cs); + if (cpu_isar_feature(aa64_sve, cpu)) { + ret = kvm_arch_put_sve(cs); + } else { + ret = kvm_arch_put_fpsimd(cs); + } + if (ret) { + return ret; + } + + reg.addr = (uintptr_t)(&fpr); + fpr = vfp_get_fpsr(env); + reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpsr); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret) { + return ret; + } + + reg.addr = (uintptr_t)(&fpr); + fpr = vfp_get_fpcr(env); + reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpcr); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); if (ret) { return ret; } @@ -878,10 +1086,8 @@ int kvm_arch_put_registers(CPUState *cs, int level) static int kvm_arch_get_fpsimd(CPUState *cs) { - ARMCPU *cpu = ARM_CPU(cs); - CPUARMState *env = &cpu->env; + CPUARMState *env = &ARM_CPU(cs)->env; struct kvm_one_reg reg; - uint32_t fpr; int i, ret; for (i = 0; i < 32; i++) { @@ -899,21 +1105,53 @@ static int kvm_arch_get_fpsimd(CPUState *cs) } } - reg.addr = (uintptr_t)(&fpr); - reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpsr); - ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); - if (ret) { - return ret; + return 0; +} + +/* + * KVM SVE registers come in slices where ZREGs have a slice size of 2048 bits + * and PREGS and the FFR have a slice size of 256 bits. However we simply hard + * code the slice index to zero for now as it's unlikely we'll need more than + * one slice for quite some time. + */ +static int kvm_arch_get_sve(CPUState *cs) +{ + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + struct kvm_one_reg reg; + uint64_t *r; + int n, ret; + + for (n = 0; n < KVM_ARM64_SVE_NUM_ZREGS; ++n) { + r = &env->vfp.zregs[n].d[0]; + reg.addr = (uintptr_t)r; + reg.id = KVM_REG_ARM64_SVE_ZREG(n, 0); + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (ret) { + return ret; + } + sve_bswap64(r, r, cpu->sve_max_vq * 2); } - vfp_set_fpsr(env, fpr); - reg.addr = (uintptr_t)(&fpr); - reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpcr); + for (n = 0; n < KVM_ARM64_SVE_NUM_PREGS; ++n) { + r = &env->vfp.pregs[n].p[0]; + reg.addr = (uintptr_t)r; + reg.id = KVM_REG_ARM64_SVE_PREG(n, 0); + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (ret) { + return ret; + } + sve_bswap64(r, r, DIV_ROUND_UP(cpu->sve_max_vq * 2, 8)); + } + + r = &env->vfp.pregs[FFR_PRED_NUM].p[0]; + reg.addr = (uintptr_t)r; + reg.id = KVM_REG_ARM64_SVE_FFR(0); ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); if (ret) { return ret; } - vfp_set_fpcr(env, fpr); + sve_bswap64(r, r, DIV_ROUND_UP(cpu->sve_max_vq * 2, 8)); return 0; } @@ -923,6 +1161,7 @@ int kvm_arch_get_registers(CPUState *cs) struct kvm_one_reg reg; uint64_t val; unsigned int el; + uint32_t fpr; int i, ret; ARMCPU *cpu = ARM_CPU(cs); @@ -1012,10 +1251,30 @@ int kvm_arch_get_registers(CPUState *cs) env->spsr = env->banked_spsr[i]; } - ret = kvm_arch_get_fpsimd(cs); + if (cpu_isar_feature(aa64_sve, cpu)) { + ret = kvm_arch_get_sve(cs); + } else { + ret = kvm_arch_get_fpsimd(cs); + } + if (ret) { + return ret; + } + + reg.addr = (uintptr_t)(&fpr); + reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpsr); + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (ret) { + return ret; + } + vfp_set_fpsr(env, fpr); + + reg.addr = (uintptr_t)(&fpr); + reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpcr); + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); if (ret) { return ret; } + vfp_set_fpcr(env, fpr); ret = kvm_get_vcpu_events(cpu); if (ret) { diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h index b4e19457a0..8e14d400e8 100644 --- a/target/arm/kvm_arm.h +++ b/target/arm/kvm_arm.h @@ -28,6 +28,20 @@ int kvm_arm_vcpu_init(CPUState *cs); /** + * kvm_arm_vcpu_finalize + * @cs: CPUState + * @feature: int + * + * Finalizes the configuration of the specified VCPU feature by + * invoking the KVM_ARM_VCPU_FINALIZE ioctl. Features requiring + * this are documented in the "KVM_ARM_VCPU_FINALIZE" section of + * KVM's API documentation. + * + * Returns: 0 if success else < 0 error code + */ +int kvm_arm_vcpu_finalize(CPUState *cs, int feature); + +/** * kvm_arm_register_device: * @mr: memory region for this device * @devid: the KVM device ID @@ -199,6 +213,17 @@ typedef struct ARMHostCPUFeatures { bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf); /** + * kvm_arm_sve_get_vls: + * @cs: CPUState + * @map: bitmap to fill in + * + * Get all the SVE vector lengths supported by the KVM host, setting + * the bits corresponding to their length in quadwords minus one + * (vq - 1) in @map up to ARM_MAX_VQ. + */ +void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map); + +/** * kvm_arm_set_cpu_features_from_host: * @cpu: ARMCPU to set the features for * @@ -226,6 +251,14 @@ bool kvm_arm_aarch32_supported(CPUState *cs); bool kvm_arm_pmu_supported(CPUState *cs); /** + * bool kvm_arm_sve_supported: + * @cs: CPUState + * + * Returns true if the KVM VCPU can enable SVE and false otherwise. + */ +bool kvm_arm_sve_supported(CPUState *cs); + +/** * kvm_arm_get_max_vm_ipa_size - Returns the number of bits in the * IPA address space supported by KVM * @@ -276,6 +309,11 @@ static inline bool kvm_arm_pmu_supported(CPUState *cs) return false; } +static inline bool kvm_arm_sve_supported(CPUState *cs) +{ + return false; +} + static inline int kvm_arm_get_max_vm_ipa_size(MachineState *ms) { return -ENOENT; @@ -289,6 +327,7 @@ static inline int kvm_arm_vgic_probe(void) static inline void kvm_arm_pmu_set_irq(CPUState *cs, int irq) {} static inline void kvm_arm_pmu_init(CPUState *cs) {} +static inline void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map) {} #endif static inline const char *gic_class_name(void) diff --git a/target/arm/monitor.c b/target/arm/monitor.c index 6457c3c87f..fa054f8a36 100644 --- a/target/arm/monitor.c +++ b/target/arm/monitor.c @@ -21,8 +21,16 @@ */ #include "qemu/osdep.h" +#include "hw/boards.h" #include "kvm_arm.h" +#include "qapi/error.h" +#include "qapi/visitor.h" +#include "qapi/qobject-input-visitor.h" +#include "qapi/qapi-commands-machine-target.h" #include "qapi/qapi-commands-misc-target.h" +#include "qapi/qmp/qerror.h" +#include "qapi/qmp/qdict.h" +#include "qom/qom-qobject.h" static GICCapability *gic_cap_new(int version) { @@ -81,3 +89,153 @@ GICCapabilityList *qmp_query_gic_capabilities(Error **errp) return head; } + +QEMU_BUILD_BUG_ON(ARM_MAX_VQ > 16); + +/* + * These are cpu model features we want to advertise. The order here + * matters as this is the order in which qmp_query_cpu_model_expansion + * will attempt to set them. If there are dependencies between features, + * then the order that considers those dependencies must be used. + */ +static const char *cpu_model_advertised_features[] = { + "aarch64", "pmu", "sve", + "sve128", "sve256", "sve384", "sve512", + "sve640", "sve768", "sve896", "sve1024", "sve1152", "sve1280", + "sve1408", "sve1536", "sve1664", "sve1792", "sve1920", "sve2048", + NULL +}; + +CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type, + CpuModelInfo *model, + Error **errp) +{ + CpuModelExpansionInfo *expansion_info; + const QDict *qdict_in = NULL; + QDict *qdict_out; + ObjectClass *oc; + Object *obj; + const char *name; + int i; + + if (type != CPU_MODEL_EXPANSION_TYPE_FULL) { + error_setg(errp, "The requested expansion type is not supported"); + return NULL; + } + + if (!kvm_enabled() && !strcmp(model->name, "host")) { + error_setg(errp, "The CPU type '%s' requires KVM", model->name); + return NULL; + } + + oc = cpu_class_by_name(TYPE_ARM_CPU, model->name); + if (!oc) { + error_setg(errp, "The CPU type '%s' is not a recognized ARM CPU type", + model->name); + return NULL; + } + + if (kvm_enabled()) { + const char *cpu_type = current_machine->cpu_type; + int len = strlen(cpu_type) - strlen(ARM_CPU_TYPE_SUFFIX); + bool supported = false; + + if (!strcmp(model->name, "host") || !strcmp(model->name, "max")) { + /* These are kvmarm's recommended cpu types */ + supported = true; + } else if (strlen(model->name) == len && + !strncmp(model->name, cpu_type, len)) { + /* KVM is enabled and we're using this type, so it works. */ + supported = true; + } + if (!supported) { + error_setg(errp, "We cannot guarantee the CPU type '%s' works " + "with KVM on this host", model->name); + return NULL; + } + } + + if (model->props) { + qdict_in = qobject_to(QDict, model->props); + if (!qdict_in) { + error_setg(errp, QERR_INVALID_PARAMETER_TYPE, "props", "dict"); + return NULL; + } + } + + obj = object_new(object_class_get_name(oc)); + + if (qdict_in) { + Visitor *visitor; + Error *err = NULL; + + visitor = qobject_input_visitor_new(model->props); + visit_start_struct(visitor, NULL, NULL, 0, &err); + if (err) { + visit_free(visitor); + object_unref(obj); + error_propagate(errp, err); + return NULL; + } + + i = 0; + while ((name = cpu_model_advertised_features[i++]) != NULL) { + if (qdict_get(qdict_in, name)) { + object_property_set(obj, visitor, name, &err); + if (err) { + break; + } + } + } + + if (!err) { + visit_check_struct(visitor, &err); + } + if (!err) { + arm_cpu_finalize_features(ARM_CPU(obj), &err); + } + visit_end_struct(visitor, NULL); + visit_free(visitor); + if (err) { + object_unref(obj); + error_propagate(errp, err); + return NULL; + } + } else { + Error *err = NULL; + arm_cpu_finalize_features(ARM_CPU(obj), &err); + assert(err == NULL); + } + + expansion_info = g_new0(CpuModelExpansionInfo, 1); + expansion_info->model = g_malloc0(sizeof(*expansion_info->model)); + expansion_info->model->name = g_strdup(model->name); + + qdict_out = qdict_new(); + + i = 0; + while ((name = cpu_model_advertised_features[i++]) != NULL) { + ObjectProperty *prop = object_property_find(obj, name, NULL); + if (prop) { + Error *err = NULL; + QObject *value; + + assert(prop->get); + value = object_property_get_qobject(obj, name, &err); + assert(!err); + + qdict_put_obj(qdict_out, name, value); + } + } + + if (!qdict_size(qdict_out)) { + qobject_unref(qdict_out); + } else { + expansion_info->model->props = QOBJECT(qdict_out); + expansion_info->model->has_props = true; + } + + object_unref(obj); + + return expansion_info; +} diff --git a/target/arm/translate-vfp.inc.c b/target/arm/translate-vfp.inc.c index 9ae980bef6..85c5ef897b 100644 --- a/target/arm/translate-vfp.inc.c +++ b/target/arm/translate-vfp.inc.c @@ -703,9 +703,10 @@ static bool trans_VMSR_VMRS(DisasContext *s, arg_VMSR_VMRS *a) if (arm_dc_feature(s, ARM_FEATURE_M)) { /* * The only M-profile VFP vmrs/vmsr sysreg is FPSCR. - * Writes to R15 are UNPREDICTABLE; we choose to undef. + * Accesses to R15 are UNPREDICTABLE; we choose to undef. + * (FPSCR -> r15 is a special case which writes to the PSR flags.) */ - if (a->rt == 15 || a->reg != ARM_VFP_FPSCR) { + if (a->rt == 15 && (!a->l || a->reg != ARM_VFP_FPSCR)) { return false; } } |