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-rw-r--r--target-arm/cpu.c1
-rw-r--r--target-arm/cpu.h1
-rw-r--r--target-arm/helper.c126
-rw-r--r--target-arm/internals.h9
-rw-r--r--target-arm/machine.c1
5 files changed, 136 insertions, 2 deletions
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 407f977742..6ab0e03dbd 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -185,6 +185,7 @@ static void arm_cpu_reset(CPUState *s)
     }
 #endif
 
+    hw_breakpoint_update_all(cpu);
     hw_watchpoint_update_all(cpu);
 }
 
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index d1e1ccb605..fa6ae0acc3 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -323,6 +323,7 @@ typedef struct CPUARMState {
     int eabi;
 #endif
 
+    struct CPUBreakpoint *cpu_breakpoint[16];
     struct CPUWatchpoint *cpu_watchpoint[16];
 
     CPU_COMMON
diff --git a/target-arm/helper.c b/target-arm/helper.c
index ece967397f..d246d36de4 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -2492,6 +2492,124 @@ static void dbgwcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
     hw_watchpoint_update(cpu, i);
 }
 
+void hw_breakpoint_update(ARMCPU *cpu, int n)
+{
+    CPUARMState *env = &cpu->env;
+    uint64_t bvr = env->cp15.dbgbvr[n];
+    uint64_t bcr = env->cp15.dbgbcr[n];
+    vaddr addr;
+    int bt;
+    int flags = BP_CPU;
+
+    if (env->cpu_breakpoint[n]) {
+        cpu_breakpoint_remove_by_ref(CPU(cpu), env->cpu_breakpoint[n]);
+        env->cpu_breakpoint[n] = NULL;
+    }
+
+    if (!extract64(bcr, 0, 1)) {
+        /* E bit clear : watchpoint disabled */
+        return;
+    }
+
+    bt = extract64(bcr, 20, 4);
+
+    switch (bt) {
+    case 4: /* unlinked address mismatch (reserved if AArch64) */
+    case 5: /* linked address mismatch (reserved if AArch64) */
+        qemu_log_mask(LOG_UNIMP,
+                      "arm: address mismatch breakpoint types not implemented");
+        return;
+    case 0: /* unlinked address match */
+    case 1: /* linked address match */
+    {
+        /* Bits [63:49] are hardwired to the value of bit [48]; that is,
+         * we behave as if the register was sign extended. Bits [1:0] are
+         * RES0. The BAS field is used to allow setting breakpoints on 16
+         * bit wide instructions; it is CONSTRAINED UNPREDICTABLE whether
+         * a bp will fire if the addresses covered by the bp and the addresses
+         * covered by the insn overlap but the insn doesn't start at the
+         * start of the bp address range. We choose to require the insn and
+         * the bp to have the same address. The constraints on writing to
+         * BAS enforced in dbgbcr_write mean we have only four cases:
+         *  0b0000  => no breakpoint
+         *  0b0011  => breakpoint on addr
+         *  0b1100  => breakpoint on addr + 2
+         *  0b1111  => breakpoint on addr
+         * See also figure D2-3 in the v8 ARM ARM (DDI0487A.c).
+         */
+        int bas = extract64(bcr, 5, 4);
+        addr = sextract64(bvr, 0, 49) & ~3ULL;
+        if (bas == 0) {
+            return;
+        }
+        if (bas == 0xc) {
+            addr += 2;
+        }
+        break;
+    }
+    case 2: /* unlinked context ID match */
+    case 8: /* unlinked VMID match (reserved if no EL2) */
+    case 10: /* unlinked context ID and VMID match (reserved if no EL2) */
+        qemu_log_mask(LOG_UNIMP,
+                      "arm: unlinked context breakpoint types not implemented");
+        return;
+    case 9: /* linked VMID match (reserved if no EL2) */
+    case 11: /* linked context ID and VMID match (reserved if no EL2) */
+    case 3: /* linked context ID match */
+    default:
+        /* We must generate no events for Linked context matches (unless
+         * they are linked to by some other bp/wp, which is handled in
+         * updates for the linking bp/wp). We choose to also generate no events
+         * for reserved values.
+         */
+        return;
+    }
+
+    cpu_breakpoint_insert(CPU(cpu), addr, flags, &env->cpu_breakpoint[n]);
+}
+
+void hw_breakpoint_update_all(ARMCPU *cpu)
+{
+    int i;
+    CPUARMState *env = &cpu->env;
+
+    /* Completely clear out existing QEMU breakpoints and our array, to
+     * avoid possible stale entries following migration load.
+     */
+    cpu_breakpoint_remove_all(CPU(cpu), BP_CPU);
+    memset(env->cpu_breakpoint, 0, sizeof(env->cpu_breakpoint));
+
+    for (i = 0; i < ARRAY_SIZE(cpu->env.cpu_breakpoint); i++) {
+        hw_breakpoint_update(cpu, i);
+    }
+}
+
+static void dbgbvr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                         uint64_t value)
+{
+    ARMCPU *cpu = arm_env_get_cpu(env);
+    int i = ri->crm;
+
+    raw_write(env, ri, value);
+    hw_breakpoint_update(cpu, i);
+}
+
+static void dbgbcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                         uint64_t value)
+{
+    ARMCPU *cpu = arm_env_get_cpu(env);
+    int i = ri->crm;
+
+    /* BAS[3] is a read-only copy of BAS[2], and BAS[1] a read-only
+     * copy of BAS[0].
+     */
+    value = deposit64(value, 6, 1, extract64(value, 5, 1));
+    value = deposit64(value, 8, 1, extract64(value, 7, 1));
+
+    raw_write(env, ri, value);
+    hw_breakpoint_update(cpu, i);
+}
+
 static void define_debug_regs(ARMCPU *cpu)
 {
     /* Define v7 and v8 architectural debug registers.
@@ -2533,11 +2651,15 @@ static void define_debug_regs(ARMCPU *cpu)
             { .name = "DBGBVR", .state = ARM_CP_STATE_BOTH,
               .cp = 14, .opc0 = 2, .opc1 = 0, .crn = 0, .crm = i, .opc2 = 4,
               .access = PL1_RW,
-              .fieldoffset = offsetof(CPUARMState, cp15.dbgbvr[i]) },
+              .fieldoffset = offsetof(CPUARMState, cp15.dbgbvr[i]),
+              .writefn = dbgbvr_write, .raw_writefn = raw_write
+            },
             { .name = "DBGBCR", .state = ARM_CP_STATE_BOTH,
               .cp = 14, .opc0 = 2, .opc1 = 0, .crn = 0, .crm = i, .opc2 = 5,
               .access = PL1_RW,
-              .fieldoffset = offsetof(CPUARMState, cp15.dbgbcr[i]) },
+              .fieldoffset = offsetof(CPUARMState, cp15.dbgbcr[i]),
+              .writefn = dbgbcr_write, .raw_writefn = raw_write
+            },
             REGINFO_SENTINEL
         };
         define_arm_cp_regs(cpu, dbgregs);
diff --git a/target-arm/internals.h b/target-arm/internals.h
index 64751a0798..b7e4822dc7 100644
--- a/target-arm/internals.h
+++ b/target-arm/internals.h
@@ -322,6 +322,15 @@ void hw_watchpoint_update(ARMCPU *cpu, int n);
  * suitable for use after migration or on reset.
  */
 void hw_watchpoint_update_all(ARMCPU *cpu);
+/* Update a QEMU breakpoint based on the information the guest has set in the
+ * DBGBCR<n>_EL1 and DBGBVR<n>_EL1 registers.
+ */
+void hw_breakpoint_update(ARMCPU *cpu, int n);
+/* Update the QEMU breakpoints for every guest breakpoint. This does a
+ * complete delete-and-reinstate of the QEMU breakpoint list and so is
+ * suitable for use after migration or on reset.
+ */
+void hw_breakpoint_update_all(ARMCPU *cpu);
 
 /* Callback function for when a watchpoint or breakpoint triggers. */
 void arm_debug_excp_handler(CPUState *cs);
diff --git a/target-arm/machine.c b/target-arm/machine.c
index 8dfe87cb6b..ddb7d05c28 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -214,6 +214,7 @@ static int cpu_post_load(void *opaque, int version_id)
         }
     }
 
+    hw_breakpoint_update_all(cpu);
     hw_watchpoint_update_all(cpu);
 
     return 0;