From fd7373cce767a8803e79f51bd3fc5f531234657f Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 20 Jan 2010 18:20:20 +0100 Subject: KVM: VMX: Clean up DR6 emulation 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 Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 23 ++++++----------------- 1 file changed, 6 insertions(+), 17 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c7b99e1f8aa..b7e812e9c29 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -579,17 +579,12 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) { u32 eb; - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) - | (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; - } + eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) | + (1u << NM_VECTOR) | (1u << DB_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) @@ -3777,9 +3772,6 @@ 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;" @@ -3880,9 +3872,6 @@ 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); -- cgit v1.2.3