On 6/8/2021 3:42 pm, Yang Weijiang wrote:
Per ISA spec, need to clear the bit before inject #DB.
Please paste the SDM statement accurately so that the reviewers
can verify that the code is consistent with the documentation.
Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 70314cd93340..31b9c06c9b3b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1601,6 +1601,21 @@ static void vmx_clear_hlt(struct kvm_vcpu *vcpu)
vmcs_write32(GUEST_ACTIVITY_STATE, GUEST_ACTIVITY_ACTIVE);
}
+static void flip_arch_lbr_ctl(struct kvm_vcpu *vcpu, bool on)
+{
+ if (vcpu_to_pmu(vcpu)->event_count > 0 &&
Ugh, this check seems ridiculous/funny to me.
+ kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR)) {
+ u64 lbr_ctl = vmcs_read64(GUEST_IA32_LBR_CTL);
+
+ if (on)
+ lbr_ctl |= 1ULL;
+ else
+ lbr_ctl &= ~1ULL;
+
+ vmcs_write64(GUEST_IA32_LBR_CTL, lbr_ctl);
+ }
+}
...
