Re: [PATCH 1/2] KVM: vmx/pmu: Fix dummy check if lbr_desc->event is created

From: Paolo Bonzini
Date: Tue Feb 23 2021 - 12:09:36 EST


On 23/02/21 02:39, Like Xu wrote:
If lbr_desc->event is successfully created, the intel_pmu_create_
guest_lbr_event() will return 0, otherwise it will return -ENOENT,
and then jump to LBR msrs dummy handling.

Fixes: 1b5ac3226a1a ("KVM: vmx/pmu: Pass-through LBR msrs when the guest LBR event is ACTIVE")
Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx/pmu_intel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index d1df618cb7de..d6a5fe19ff09 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -320,7 +320,7 @@ static bool intel_pmu_handle_lbr_msrs_access(struct kvm_vcpu *vcpu,
if (!intel_pmu_is_valid_lbr_msr(vcpu, index))
return false;
- if (!lbr_desc->event && !intel_pmu_create_guest_lbr_event(vcpu))
+ if (!lbr_desc->event && intel_pmu_create_guest_lbr_event(vcpu))
goto dummy;

Queued, adding a "< 0" to clarify the semantics of the function.

Paolo