diff mbox

[3/6] KVM: VMX: Clean up DR6 emulation

Message ID 20090904125119.18939.18642.stgit@mchn012c.ww002.siemens.net (mailing list archive)
State New, archived
Headers show

Commit Message

Jan Kiszka Sept. 4, 2009, 12:51 p.m. UTC 
As we trap all debug register accesses, we do not need to switch real
DR6 at all. Clean up update_exception_bitmap at this chance, too.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

 arch/x86/kvm/vmx.c |   22 ++++++----------------
 1 files changed, 6 insertions(+), 16 deletions(-)


--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d3213ac..7012680 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -536,18 +536,14 @@  static void update_exception_bitmap(struct kvm_vcpu *vcpu)
 {
 	u32 eb;
 
-	eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR);
+	eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
+	     (1u << DB_VECTOR);
 	if (!vcpu->fpu_active)
 		eb |= 1u << NM_VECTOR;
-	/*
-	 * Unconditionally intercept #DB so we can maintain dr6 without
-	 * reading it every exit.
-	 */
-	eb |= 1u << DB_VECTOR;
-	if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) {
-		if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
-			eb |= 1u << BP_VECTOR;
-	}
+	if ((vcpu->guest_debug &
+	     (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
+	    (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP))
+		eb |= 1u << BP_VECTOR;
 	if (to_vmx(vcpu)->rmode.vm86_active)
 		eb = ~0;
 	if (enable_ept)
@@ -3627,9 +3623,6 @@  static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	 */
 	vmcs_writel(HOST_CR0, read_cr0());
 
-	if (vcpu->arch.switch_db_regs)
-		set_debugreg(vcpu->arch.dr6, 6);
-
 	asm(
 		/* Store host registers */
 		"push %%"R"dx; push %%"R"bp;"
@@ -3730,9 +3723,6 @@  static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
 				  | (1 << VCPU_EXREG_PDPTR));
 	vcpu->arch.regs_dirty = 0;
 
-	if (vcpu->arch.switch_db_regs)
-		get_debugreg(vcpu->arch.dr6, 6);
-
 	vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
 	if (vmx->rmode.irq.pending)
 		fixup_rmode_irq(vmx);