Messages in this thread | | | Subject | Re: [PATCH v6 8/8] kvm: vmx: virtualize split lock detection | From | Xiaoyao Li <> | Date | Thu, 26 Mar 2020 14:41:14 +0800 |
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On 3/25/2020 8:40 AM, Thomas Gleixner wrote: > Xiaoyao Li <xiaoyao.li@intel.com> 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
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