diff options
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index dc6ecfa5a2d2..aac7808ce216 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -5,13 +5,14 @@ * Copyright 2018 Arm Limited * Author: Dave Martin <Dave.Martin@arm.com> */ -#include <linux/bottom_half.h> +#include <linux/irqflags.h> #include <linux/sched.h> #include <linux/thread_info.h> #include <linux/kvm_host.h> #include <asm/kvm_asm.h> #include <asm/kvm_host.h> #include <asm/kvm_mmu.h> +#include <asm/sysreg.h> /* * Called on entry to KVM_RUN unless this vcpu previously ran at least @@ -61,10 +62,16 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) { BUG_ON(!current->mm); - vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_HOST_SVE_IN_USE); + vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | + KVM_ARM64_HOST_SVE_IN_USE | + KVM_ARM64_HOST_SVE_ENABLED); vcpu->arch.flags |= KVM_ARM64_FP_HOST; + if (test_thread_flag(TIF_SVE)) vcpu->arch.flags |= KVM_ARM64_HOST_SVE_IN_USE; + + if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) + vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED; } /* @@ -92,19 +99,30 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) */ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) { - local_bh_disable(); + unsigned long flags; - update_thread_flag(TIF_SVE, - vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE); + local_irq_save(flags); if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { /* Clean guest FP state to memory and invalidate cpu view */ fpsimd_save(); fpsimd_flush_cpu_state(); - } else if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) { - /* Ensure user trap controls are correctly restored */ - fpsimd_bind_task_to_cpu(); + } else if (system_supports_sve()) { + /* + * The FPSIMD/SVE state in the CPU has not been touched, and we + * have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been + * reset to CPACR_EL1_DEFAULT by the Hyp code, disabling SVE + * for EL0. To avoid spurious traps, restore the trap state + * seen by kvm_arch_vcpu_load_fp(): + */ + if (vcpu->arch.flags & KVM_ARM64_HOST_SVE_ENABLED) + sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN); + else + sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0); } - local_bh_enable(); + update_thread_flag(TIF_SVE, + vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE); + + local_irq_restore(flags); } |