On 3/25/2020 8:40 AM, Thomas Gleixner wrote:
Xiaoyao Li <xiaoyao.li@xxxxxxxxx> writes:+static inline bool guest_cpu_split_lock_detect_on(struct vcpu_vmx *vmx) +{ + return vmx->msr_test_ctrl & MSR_TEST_CTRL_SPLIT_LOCK_DETECT; +} + static int handle_exception_nmi(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -4725,12 +4746,13 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) case AC_VECTOR: /* * Reflect #AC to the guest if it's expecting the #AC, i.e. has - * legacy alignment check enabled. Pre-check host split lock - * support to avoid the VMREADs needed to check legacy #AC, - * i.e. reflect the #AC if the only possible source is legacy - * alignment checks. + * legacy alignment check enabled or split lock detect enabled. + * Pre-check host split lock support to avoid further check of + * guest, i.e. reflect the #AC if host doesn't enable split lock + * detection. */ if (!split_lock_detect_on() || + guest_cpu_split_lock_detect_on(vmx) || guest_cpu_alignment_check_enabled(vcpu)) {If the host has split lock detection disabled then how is the guest supposed to have it enabled in the first place?
It is || Thanks, -Xiaoyao
