1 files changed, 66 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8589cc02789e..89313187d7f7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4956,6 +4956,62 @@ static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
 static int complete_emulated_mmio(struct kvm_vcpu *vcpu);
 static int complete_emulated_pio(struct kvm_vcpu *vcpu);
 
+static int kvm_vcpu_check_hw_bp(unsigned long addr, u32 type, u32 dr7,
+                                unsigned long *db)
+{
+        u32 dr6 = 0;
+        int i;
+        u32 enable, rwlen;
+
+        enable = dr7;
+        rwlen = dr7 >> 16;
+        for (i = 0; i < 4; i++, enable >>= 2, rwlen >>= 4)
+                if ((enable & 3) && (rwlen & 15) == type && db[i] == addr)
+                        dr6 |= (1 << i);
+        return dr6;
+}
+
+static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r)
+{
+        struct kvm_run *kvm_run = vcpu->run;
+        unsigned long eip = vcpu->arch.emulate_ctxt.eip;
+        u32 dr6 = 0;
+
+        if (unlikely(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) &&
+            (vcpu->arch.guest_debug_dr7 & DR7_BP_EN_MASK)) {
+                dr6 = kvm_vcpu_check_hw_bp(eip, 0,
+                                           vcpu->arch.guest_debug_dr7,
+                                           vcpu->arch.eff_db);
+
+                if (dr6 != 0) {
+                        kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1;
+                        kvm_run->debug.arch.pc = kvm_rip_read(vcpu) +
+                                get_segment_base(vcpu, VCPU_SREG_CS);
+
+                        kvm_run->debug.arch.exception = DB_VECTOR;
+                        kvm_run->exit_reason = KVM_EXIT_DEBUG;
+                        *r = EMULATE_USER_EXIT;
+                        return true;
+                }
+        }
+
+        if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK)) {
+                dr6 = kvm_vcpu_check_hw_bp(eip, 0,
+                                           vcpu->arch.dr7,
+                                           vcpu->arch.db);
+
+                if (dr6 != 0) {
+                        vcpu->arch.dr6 &= ~15;
+                        vcpu->arch.dr6 |= dr6;
+                        kvm_queue_exception(vcpu, DB_VECTOR);
+                        *r = EMULATE_DONE;
+                        return true;
+                }
+        }
+
+        return false;
+}
+
 int x86_emulate_instruction(struct kvm_vcpu *vcpu,
                             unsigned long cr2,
                             int emulation_type,
@@ -4976,6 +5032,16 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
 
         if (!(emulation_type & EMULTYPE_NO_DECODE)) {
                 init_emulate_ctxt(vcpu);
+
+                /*
+                 * We will reenter on the same instruction since
+                 * we do not set complete_userspace_io.  This does not
+                 * handle watchpoints yet, those would be handled in
+                 * the emulate_ops.
+                 */
+                if (kvm_vcpu_check_breakpoint(vcpu, &r))
+                        return r;
+
                 ctxt->interruptibility = 0;
                 ctxt->have_exception = false;
                 ctxt->perm_ok = false;