1 files changed, 72 insertions, 0 deletions
diff --git a/target-arm/kvm64.c b/target-arm/kvm64.c
index d0877946b1..3b3929dc24 100644
--- a/target-arm/kvm64.c
+++ b/target-arm/kvm64.c
@@ -18,6 +18,7 @@
 #include "config-host.h"
 #include "qemu-common.h"
 #include "qemu/timer.h"
+#include "qemu/error-report.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
 #include "kvm_arm.h"
@@ -481,3 +482,74 @@ int kvm_arch_get_registers(CPUState *cs)
     /* TODO: other registers */
     return ret;
 }
+
+/* C6.6.29 BRK instruction */
+static const uint32_t brk_insn = 0xd4200000;
+
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+{
+    if (have_guest_debug) {
+        if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
+            cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&brk_insn, 4, 1)) {
+            return -EINVAL;
+        }
+        return 0;
+    } else {
+        error_report("guest debug not supported on this kernel");
+        return -EINVAL;
+    }
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+{
+    static uint32_t brk;
+
+    if (have_guest_debug) {
+        if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&brk, 4, 0) ||
+            brk != brk_insn ||
+            cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
+            return -EINVAL;
+        }
+        return 0;
+    } else {
+        error_report("guest debug not supported on this kernel");
+        return -EINVAL;
+    }
+}
+
+/* See v8 ARM ARM D7.2.27 ESR_ELx, Exception Syndrome Register
+ *
+ * To minimise translating between kernel and user-space the kernel
+ * ABI just provides user-space with the full exception syndrome
+ * register value to be decoded in QEMU.
+ */
+
+bool kvm_arm_handle_debug(CPUState *cs, struct kvm_debug_exit_arch *debug_exit)
+{
+    int hsr_ec = debug_exit->hsr >> ARM_EL_EC_SHIFT;
+    ARMCPU *cpu = ARM_CPU(cs);
+    CPUARMState *env = &cpu->env;
+
+    /* Ensure PC is synchronised */
+    kvm_cpu_synchronize_state(cs);
+
+    switch (hsr_ec) {
+    case EC_AA64_BKPT:
+        if (kvm_find_sw_breakpoint(cs, env->pc)) {
+            return true;
+        }
+        break;
+    default:
+        error_report("%s: unhandled debug exit (%"PRIx32", %"PRIx64")\n",
+                     __func__, debug_exit->hsr, env->pc);
+    }
+
+    /* If we don't handle this it could be it really is for the
+       guest to handle */
+    qemu_log_mask(LOG_UNIMP,
+                  "%s: re-injecting exception not yet implemented"
+                  " (0x%"PRIx32", %"PRIx64")\n",
+                  __func__, hsr_ec, env->pc);
+
+    return false;
+}