diff options
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 6012b08ecb14..edbc0183c89b 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -107,16 +107,19 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) } /* - * Called just before entering the guest once we are no longer - * preemptable. Syncs the host's TIF_FOREIGN_FPSTATE with the KVM - * mirror of the flag used by the hypervisor. + * Called just before entering the guest once we are no longer preemptable + * and interrupts are disabled. If we have managed to run anything using + * FP while we were preemptible (such as off the back of an interrupt), + * then neither the host nor the guest own the FP hardware (and it was the + * responsibility of the code that used FP to save the existing state). + * + * Note that not supporting FP is basically the same thing as far as the + * hypervisor is concerned (nothing to save). */ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) { - if (test_thread_flag(TIF_FOREIGN_FPSTATE)) - vcpu->arch.flags |= KVM_ARM64_FP_FOREIGN_FPSTATE; - else - vcpu->arch.flags &= ~KVM_ARM64_FP_FOREIGN_FPSTATE; + if (!system_supports_fpsimd() || test_thread_flag(TIF_FOREIGN_FPSTATE)) + vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_FP_HOST); } /* |