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_EL1 and DBGBVR_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;