Re: [PATCH v11 13/16] KVM: x86/vmx: Clear Arch LBREn bit before inject #DB to guest

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 5/5/2022 11:33 PM, Yang Weijiang wrote:
On a debug breakpoint event (#DB), IA32_LBR_CTL.LBREn is cleared.
So need to clear the bit manually before inject #DB.

Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>

Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

---
  arch/x86/kvm/vmx/vmx.c | 27 +++++++++++++++++++++++++++
  1 file changed, 27 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e6384ef1d115..6d6ee9cf82f5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1605,6 +1605,27 @@ 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)
+{
+	struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu);
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+
+	if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR) &&
+	    test_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use) &&
+	    lbr_desc->event) {
+		u64 old = vmcs_read64(GUEST_IA32_LBR_CTL);
+		u64 new;
+
+		if (on)
+			new = old | ARCH_LBR_CTL_LBREN;
+		else
+			new = old & ~ARCH_LBR_CTL_LBREN;
+
+		if (old != new)
+			vmcs_write64(GUEST_IA32_LBR_CTL, new);
+	}
+}
+
  static void vmx_queue_exception(struct kvm_vcpu *vcpu)
  {
  	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -1640,6 +1661,9 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu)
  	vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info);
vmx_clear_hlt(vcpu);
+
+	if (nr == DB_VECTOR)
+		flip_arch_lbr_ctl(vcpu, false);
  }
static void vmx_setup_uret_msr(struct vcpu_vmx *vmx, unsigned int msr,
@@ -4645,6 +4669,9 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
  			INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR);
vmx_clear_hlt(vcpu);
+
+	if (vcpu->arch.exception.nr == DB_VECTOR)
+		flip_arch_lbr_ctl(vcpu, false);
  }
bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu)



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux