Messages in this thread Patch in this message | | | From | Hao Xiang <> | Subject | [PATCH v3] KVM: VMX: Remove redundant handling of bus lock vmexit | Date | Fri, 15 Oct 2021 19:59:21 +0800 |
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Hardware may or may not set exit_reason.bus_lock_detected on BUS_LOCK VM-Exits. Dealing with KVM_RUN_X86_BUS_LOCK in handle_bus_lock_vmexit could be redundant when exit_reason.basic is EXIT_REASON_BUS_LOCK.
We can remove redundant handling of bus lock vmexit. Unconditionally Set exit_reason.bus_lock_detected in handle_bus_lock_vmexit(), and deal with KVM_RUN_X86_BUS_LOCK only in vmx_handle_exit().
Suggested-by: Xiaoyao Li <xiaoyao.li@intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Hao Xiang <hao.xiang@linux.alibaba.com> --- v1 -> v2: a little modifications of comments v2 -> v3: addressed the review comments
arch/x86/kvm/vmx/vmx.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 116b089..7fb2a3a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5562,9 +5562,13 @@ static int handle_encls(struct kvm_vcpu *vcpu) static int handle_bus_lock_vmexit(struct kvm_vcpu *vcpu) { - vcpu->run->exit_reason = KVM_EXIT_X86_BUS_LOCK; - vcpu->run->flags |= KVM_RUN_X86_BUS_LOCK; - return 0; + /* + * Hardware may or may not set the BUS_LOCK_DETECTED flag on BUS_LOCK + * VM-Exits. Unconditionally set the flag here and leave the handling to + * vmx_handle_exit(). + */ + to_vmx(vcpu)->exit_reason.bus_lock_detected = true; + return 1; } /* @@ -6051,9 +6055,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) int ret = __vmx_handle_exit(vcpu, exit_fastpath); /* - * Even when current exit reason is handled by KVM internally, we - * still need to exit to user space when bus lock detected to inform - * that there is a bus lock in guest. + * Exit to user space when bus lock detected to inform that there is + * a bus lock in guest. */ if (to_vmx(vcpu)->exit_reason.bus_lock_detected) { if (ret > 0) -- 1.8.3.1
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