diff options
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 27 | ||||
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 9 |
4 files changed, 35 insertions, 5 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 341705fcb7bb..0ad683dab1e2 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -61,7 +61,8 @@ extern void fpsimd_kvm_prepare(void); extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state, void *sve_state, unsigned int sve_vl, void *za_state, unsigned int sme_vl, - u64 *svcr, enum fp_type *type); + u64 *svcr, enum fp_type *type, + enum fp_type to_save); extern void fpsimd_flush_task_state(struct task_struct *target); extern void fpsimd_save_and_flush_cpu_state(void); diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 3cce0a4c4e8d..09f39a2bab47 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -123,6 +123,7 @@ enum vec_type { }; enum fp_type { + FP_STATE_CURRENT, /* Save based on current task state. */ FP_STATE_FPSIMD, FP_STATE_SVE, }; diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index aacd8e356084..21775f3db58a 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -126,6 +126,7 @@ struct fpsimd_last_state_struct { unsigned int sve_vl; unsigned int sme_vl; enum fp_type *fp_type; + enum fp_type to_save; }; static DEFINE_PER_CPU(struct fpsimd_last_state_struct, fpsimd_last_state); @@ -356,7 +357,8 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type, * but userspace is discouraged from relying on this. * * task->thread.sve_state does not need to be non-NULL, valid or any - * particular size: it must not be dereferenced. + * particular size: it must not be dereferenced and any data stored + * there should be considered stale and not referenced. * * * SVE state - FP_STATE_SVE: * @@ -369,7 +371,9 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type, * task->thread.uw.fpsimd_state should be ignored. * * task->thread.sve_state must point to a valid buffer at least - * sve_state_size(task) bytes in size. + * sve_state_size(task) bytes in size. The data stored in + * task->thread.uw.fpsimd_state.vregs should be considered stale + * and not referenced. * * * FPSR and FPCR are always stored in task->thread.uw.fpsimd_state * irrespective of whether TIF_SVE is clear or set, since these are @@ -459,6 +463,21 @@ static void fpsimd_save(void) vl = last->sve_vl; } + /* + * Validate that an explicitly specified state to save is + * consistent with the task state. + */ + switch (last->to_save) { + case FP_STATE_CURRENT: + break; + case FP_STATE_FPSIMD: + WARN_ON_ONCE(save_sve_regs); + break; + case FP_STATE_SVE: + WARN_ON_ONCE(!save_sve_regs); + break; + } + if (system_supports_sme()) { u64 *svcr = last->svcr; @@ -1693,6 +1712,7 @@ static void fpsimd_bind_task_to_cpu(void) last->sme_vl = task_get_sme_vl(current); last->svcr = ¤t->thread.svcr; last->fp_type = ¤t->thread.fp_type; + last->to_save = FP_STATE_CURRENT; current->thread.fpsimd_cpu = smp_processor_id(); /* @@ -1717,7 +1737,7 @@ static void fpsimd_bind_task_to_cpu(void) void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state, unsigned int sve_vl, void *za_state, unsigned int sme_vl, u64 *svcr, - enum fp_type *type) + enum fp_type *type, enum fp_type to_save) { struct fpsimd_last_state_struct *last = this_cpu_ptr(&fpsimd_last_state); @@ -1732,6 +1752,7 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state, last->sve_vl = sve_vl; last->sme_vl = sme_vl; last->fp_type = type; + last->to_save = to_save; } /* diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index a4b4502ad850..89c02ce797b8 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -130,9 +130,16 @@ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) */ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) { + enum fp_type fp_type; + WARN_ON_ONCE(!irqs_disabled()); if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) { + if (vcpu_has_sve(vcpu)) + fp_type = FP_STATE_SVE; + else + fp_type = FP_STATE_FPSIMD; + /* * Currently we do not support SME guests so SVCR is * always 0 and we just need a variable to point to. @@ -141,7 +148,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) vcpu->arch.sve_state, vcpu->arch.sve_max_vl, NULL, 0, &vcpu->arch.svcr, - &vcpu->arch.fp_type); + &vcpu->arch.fp_type, fp_type); clear_thread_flag(TIF_FOREIGN_FPSTATE); update_thread_flag(TIF_SVE, vcpu_has_sve(vcpu)); |