diff options
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index f03bffafd9e6..a862c768fd54 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1672,12 +1672,14 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd) mark_dirty(svm->vmcb, VMCB_ASID); } -static void svm_set_dr6(struct kvm_vcpu *vcpu, unsigned long value) +static void svm_set_dr6(struct vcpu_svm *svm, unsigned long value) { - struct vcpu_svm *svm = to_svm(vcpu); + struct vmcb *vmcb = svm->vmcb; - svm->vmcb->save.dr6 = value; - mark_dirty(svm->vmcb, VMCB_DR); + if (unlikely(value != vmcb->save.dr6)) { + vmcb->save.dr6 = value; + mark_dirty(vmcb, VMCB_DR); + } } static void svm_sync_dirty_debug_regs(struct kvm_vcpu *vcpu) @@ -1688,9 +1690,12 @@ static void svm_sync_dirty_debug_regs(struct kvm_vcpu *vcpu) get_debugreg(vcpu->arch.db[1], 1); get_debugreg(vcpu->arch.db[2], 2); get_debugreg(vcpu->arch.db[3], 3); + /* + * We cannot reset svm->vmcb->save.dr6 to DR6_FIXED_1|DR6_RTM here, + * because db_interception might need it. We can do it before vmentry. + */ vcpu->arch.dr6 = svm->vmcb->save.dr6; vcpu->arch.dr7 = svm->vmcb->save.dr7; - vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_WONT_EXIT; set_dr_intercepts(svm); } @@ -1734,8 +1739,8 @@ static int db_interception(struct vcpu_svm *svm) if (!(svm->vcpu.guest_debug & (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) && !svm->nmi_singlestep) { - vcpu->arch.dr6 = svm->vmcb->save.dr6; - kvm_queue_exception(&svm->vcpu, DB_VECTOR); + u32 payload = (svm->vmcb->save.dr6 ^ DR6_RTM) & ~DR6_FIXED_1; + kvm_queue_exception_p(&svm->vcpu, DB_VECTOR, payload); return 1; } @@ -3313,6 +3318,15 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) svm->vmcb->save.cr2 = vcpu->arch.cr2; + /* + * Run with all-zero DR6 unless needed, so that we can get the exact cause + * of a #DB. + */ + if (unlikely(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)) + svm_set_dr6(svm, vcpu->arch.dr6); + else + svm_set_dr6(svm, DR6_FIXED_1 | DR6_RTM); + clgi(); kvm_load_guest_xsave_state(vcpu); @@ -3927,7 +3941,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .set_idt = svm_set_idt, .get_gdt = svm_get_gdt, .set_gdt = svm_set_gdt, - .set_dr6 = svm_set_dr6, .set_dr7 = svm_set_dr7, .sync_dirty_debug_regs = svm_sync_dirty_debug_regs, .cache_reg = svm_cache_reg, |