Merge branch 'kvm-amd-fixes' into HEAD

[linux-block.git] / arch / x86 / kvm / svm / svm.c

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index c86f7278509bbdcf257d18cd8231aa79780a4c40..b627564e41f9e6595c68592d9311b2d59bb116f3 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1673,17 +1673,14 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
        mark_dirty(svm->vmcb, VMCB_ASID);
 }
 
-static u64 svm_get_dr6(struct kvm_vcpu *vcpu)
+static void svm_set_dr6(struct vcpu_svm *svm, unsigned long value)
 {
-       return to_svm(vcpu)->vmcb->save.dr6;
-}
-
-static void svm_set_dr6(struct kvm_vcpu *vcpu, 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)
@@ -1694,9 +1691,12 @@ 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);
-       vcpu->arch.dr6 = svm_get_dr6(vcpu);
+       /*
+        * 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);
 }
@@ -1740,7 +1740,8 @@ static int db_interception(struct vcpu_svm *svm)
        if (!(svm->vcpu.guest_debug &
              (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) &&
                !svm->nmi_singlestep) {
-               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;
        }
 
@@ -1753,6 +1754,8 @@ static int db_interception(struct vcpu_svm *svm)
        if (svm->vcpu.guest_debug &
            (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) {
                kvm_run->exit_reason = KVM_EXIT_DEBUG;
+               kvm_run->debug.arch.dr6 = svm->vmcb->save.dr6;
+               kvm_run->debug.arch.dr7 = svm->vmcb->save.dr7;
                kvm_run->debug.arch.pc =
                        svm->vmcb->save.cs.base + svm->vmcb->save.rip;
                kvm_run->debug.arch.exception = DB_VECTOR;
@@ -3349,6 +3352,15 @@ static enum exit_fastpath_completion 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);
 
@@ -3967,8 +3979,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
        .set_idt = svm_set_idt,
        .get_gdt = svm_get_gdt,
        .set_gdt = svm_set_gdt,
-       .get_dr6 = svm_get_dr6,
-       .set_dr6 = svm_set_dr6,
        .set_dr7 = svm_set_dr7,
        .sync_dirty_debug_regs = svm_sync_dirty_debug_regs,
        .cache_reg = svm_cache_reg,