5 files changed, 111 insertions, 73 deletions

diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index 886c9402ec45..32eb96c7ca27 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -212,6 +212,24 @@ struct kvm_pit_channel_state {
         __s64 count_load_time;
 };
 
+struct kvm_debug_exit_arch {
+        __u32 exception;
+        __u32 pad;
+        __u64 pc;
+        __u64 dr6;
+        __u64 dr7;
+};
+
+#define KVM_GUESTDBG_USE_SW_BP          0x00010000
+#define KVM_GUESTDBG_USE_HW_BP          0x00020000
+#define KVM_GUESTDBG_INJECT_DB          0x00040000
+#define KVM_GUESTDBG_INJECT_BP          0x00080000
+
+/* for KVM_SET_GUEST_DEBUG */
+struct kvm_guest_debug_arch {
+        __u64 debugreg[8];
+};
+
 struct kvm_pit_state {
         struct kvm_pit_channel_state channels[3];
 };
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 53779309514a..c430cd580ee2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -135,12 +135,6 @@ enum {
 
 #define KVM_NR_MEM_OBJS 40
 
-struct kvm_guest_debug {
-        int enabled;
-        unsigned long bp[4];
-        int singlestep;
-};
-
 /*
  * We don't want allocation failures within the mmu code, so we preallocate
  * enough memory for a single page fault in a cache.
@@ -448,8 +442,7 @@ struct kvm_x86_ops {
         void (*vcpu_put)(struct kvm_vcpu *vcpu);
 
         int (*set_guest_debug)(struct kvm_vcpu *vcpu,
-                               struct kvm_debug_guest *dbg);
-        void (*guest_debug_pre)(struct kvm_vcpu *vcpu);
+                               struct kvm_guest_debug *dbg);
         int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
         int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
         u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0fbbde54ecae..88d9062f4545 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -968,9 +968,32 @@ static void svm_set_segment(struct kvm_vcpu *vcpu,
 
 }
 
-static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg)
+static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
 {
-        return -EOPNOTSUPP;
+        int old_debug = vcpu->guest_debug;
+        struct vcpu_svm *svm = to_svm(vcpu);
+
+        vcpu->guest_debug = dbg->control;
+
+        svm->vmcb->control.intercept_exceptions &=
+                ~((1 << DB_VECTOR) | (1 << BP_VECTOR));
+        if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) {
+                if (vcpu->guest_debug &
+                    (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
+                        svm->vmcb->control.intercept_exceptions |=
+                                1 << DB_VECTOR;
+                if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
+                        svm->vmcb->control.intercept_exceptions |=
+                                1 << BP_VECTOR;
+        } else
+                vcpu->guest_debug = 0;
+
+        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
+                svm->vmcb->save.rflags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
+        else if (old_debug & KVM_GUESTDBG_SINGLESTEP)
+                svm->vmcb->save.rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
+
+        return 0;
 }
 
 static int svm_get_irq(struct kvm_vcpu *vcpu)
@@ -1094,6 +1117,27 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
         return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code);
 }
 
+static int db_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+        if (!(svm->vcpu.guest_debug &
+              (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) {
+                kvm_queue_exception(&svm->vcpu, DB_VECTOR);
+                return 1;
+        }
+        kvm_run->exit_reason = KVM_EXIT_DEBUG;
+        kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip;
+        kvm_run->debug.arch.exception = DB_VECTOR;
+        return 0;
+}
+
+static int bp_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+        kvm_run->exit_reason = KVM_EXIT_DEBUG;
+        kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip;
+        kvm_run->debug.arch.exception = BP_VECTOR;
+        return 0;
+}
+
 static int ud_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
 {
         int er;
@@ -2050,6 +2094,8 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
         [SVM_EXIT_WRITE_DR3]                    = emulate_on_interception,
         [SVM_EXIT_WRITE_DR5]                    = emulate_on_interception,
         [SVM_EXIT_WRITE_DR7]                    = emulate_on_interception,
+        [SVM_EXIT_EXCP_BASE + DB_VECTOR]        = db_interception,
+        [SVM_EXIT_EXCP_BASE + BP_VECTOR]        = bp_interception,
         [SVM_EXIT_EXCP_BASE + UD_VECTOR]        = ud_interception,
         [SVM_EXIT_EXCP_BASE + PF_VECTOR]        = pf_interception,
         [SVM_EXIT_EXCP_BASE + NM_VECTOR]        = nm_interception,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1d974c1eaa7d..f55690ddb3ac 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -480,8 +480,13 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
         eb = (1u << PF_VECTOR) | (1u << UD_VECTOR);
         if (!vcpu->fpu_active)
                 eb |= 1u << NM_VECTOR;
-        if (vcpu->guest_debug.enabled)
-                eb |= 1u << DB_VECTOR;
+        if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) {
+                if (vcpu->guest_debug &
+                    (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
+                        eb |= 1u << DB_VECTOR;
+                if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
+                        eb |= 1u << BP_VECTOR;
+        }
         if (vcpu->arch.rmode.active)
                 eb = ~0;
         if (vm_need_ept())
@@ -1003,40 +1008,23 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
         }
 }
 
-static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg)
+static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
 {
-        unsigned long dr7 = 0x400;
-        int old_singlestep;
-
-        old_singlestep = vcpu->guest_debug.singlestep;
-
-        vcpu->guest_debug.enabled = dbg->enabled;
-        if (vcpu->guest_debug.enabled) {
-                int i;
-
-                dr7 |= 0x200;  /* exact */
-                for (i = 0; i < 4; ++i) {
-                        if (!dbg->breakpoints[i].enabled)
-                                continue;
-                        vcpu->guest_debug.bp[i] = dbg->breakpoints[i].address;
-                        dr7 |= 2 << (i*2);    /* global enable */
-                        dr7 |= 0 << (i*4+16); /* execution breakpoint */
-                }
-
-                vcpu->guest_debug.singlestep = dbg->singlestep;
-        } else
-                vcpu->guest_debug.singlestep = 0;
+        int old_debug = vcpu->guest_debug;
+        unsigned long flags;
 
-        if (old_singlestep && !vcpu->guest_debug.singlestep) {
-                unsigned long flags;
+        vcpu->guest_debug = dbg->control;
+        if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
+                vcpu->guest_debug = 0;
 
-                flags = vmcs_readl(GUEST_RFLAGS);
+        flags = vmcs_readl(GUEST_RFLAGS);
+        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
+                flags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
+        else if (old_debug & KVM_GUESTDBG_SINGLESTEP)
                 flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
-                vmcs_writel(GUEST_RFLAGS, flags);
-        }
+        vmcs_writel(GUEST_RFLAGS, flags);
 
         update_exception_bitmap(vcpu);
-        vmcs_writel(GUEST_DR7, dr7);
 
         return 0;
 }
@@ -2540,24 +2528,6 @@ static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr)
         return 0;
 }
 
-static void kvm_guest_debug_pre(struct kvm_vcpu *vcpu)
-{
-        struct kvm_guest_debug *dbg = &vcpu->guest_debug;
-
-        set_debugreg(dbg->bp[0], 0);
-        set_debugreg(dbg->bp[1], 1);
-        set_debugreg(dbg->bp[2], 2);
-        set_debugreg(dbg->bp[3], 3);
-
-        if (dbg->singlestep) {
-                unsigned long flags;
-
-                flags = vmcs_readl(GUEST_RFLAGS);
-                flags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
-                vmcs_writel(GUEST_RFLAGS, flags);
-        }
-}
-
 static int handle_rmode_exception(struct kvm_vcpu *vcpu,
                                   int vec, u32 err_code)
 {
@@ -2574,9 +2544,17 @@ static int handle_rmode_exception(struct kvm_vcpu *vcpu,
          *        the required debugging infrastructure rework.
          */
         switch (vec) {
-        case DE_VECTOR:
         case DB_VECTOR:
+                if (vcpu->guest_debug &
+                    (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
+                        return 0;
+                kvm_queue_exception(vcpu, vec);
+                return 1;
         case BP_VECTOR:
+                if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
+                        return 0;
+                /* fall through */
+        case DE_VECTOR:
         case OF_VECTOR:
         case BR_VECTOR:
         case UD_VECTOR:
@@ -2593,7 +2571,7 @@ static int handle_rmode_exception(struct kvm_vcpu *vcpu,
 static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
         struct vcpu_vmx *vmx = to_vmx(vcpu);
-        u32 intr_info, error_code;
+        u32 intr_info, ex_no, error_code;
         unsigned long cr2, rip;
         u32 vect_info;
         enum emulation_result er;
@@ -2653,14 +2631,16 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 return 1;
         }
 
-        if ((intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK)) ==
-            (INTR_TYPE_HARD_EXCEPTION | 1)) {
+        ex_no = intr_info & INTR_INFO_VECTOR_MASK;
+        if (ex_no == DB_VECTOR || ex_no == BP_VECTOR) {
                 kvm_run->exit_reason = KVM_EXIT_DEBUG;
-                return 0;
+                kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip;
+                kvm_run->debug.arch.exception = ex_no;
+        } else {
+                kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
+                kvm_run->ex.exception = ex_no;
+                kvm_run->ex.error_code = error_code;
         }
-        kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
-        kvm_run->ex.exception = intr_info & INTR_INFO_VECTOR_MASK;
-        kvm_run->ex.error_code = error_code;
         return 0;
 }
 
@@ -3600,7 +3580,6 @@ static struct kvm_x86_ops vmx_x86_ops = {
         .vcpu_put = vmx_vcpu_put,
 
         .set_guest_debug = set_guest_debug,
-        .guest_debug_pre = kvm_guest_debug_pre,
         .get_msr = vmx_get_msr,
         .set_msr = vmx_set_msr,
         .get_segment_base = vmx_get_segment_base,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b5e9932e0f62..e990d164b56d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3005,9 +3005,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 goto out;
         }
 
-        if (vcpu->guest_debug.enabled)
-                kvm_x86_ops->guest_debug_pre(vcpu);
-
         vcpu->guest_mode = 1;
         /*
          * Make sure that guest_mode assignment won't happen after
@@ -3218,7 +3215,7 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         /*
          * Don't leak debug flags in case they were set for guest debugging
          */
-        if (vcpu->guest_debug.enabled && vcpu->guest_debug.singlestep)
+        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                 regs->rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
 
         vcpu_put(vcpu);
@@ -3837,8 +3834,8 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
         return 0;
 }
 
-int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
-                                    struct kvm_debug_guest *dbg)
+int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
+                                        struct kvm_guest_debug *dbg)
 {
         int r;
 
@@ -3846,6 +3843,11 @@ int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
 
         r = kvm_x86_ops->set_guest_debug(vcpu, dbg);
 
+        if (dbg->control & KVM_GUESTDBG_INJECT_DB)
+                kvm_queue_exception(vcpu, DB_VECTOR);
+        else if (dbg->control & KVM_GUESTDBG_INJECT_BP)
+                kvm_queue_exception(vcpu, BP_VECTOR);
+
         vcpu_put(vcpu);
 
         return r;