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* [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs
@ 2022-01-05  3:01 Bin Meng
  2022-01-05  3:01 ` [PATCH v3 1/7] target/riscv: Add initial support for native debug Bin Meng
                   ` (6 more replies)
  0 siblings, 7 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv


This adds initial support for the native debug via the Trigger Module,
as defined in the RISC-V Debug Specification [1].

Only "Address / Data Match" trigger (type 2) is implemented as of now,
which is mainly used for hardware breakpoint and watchpoint. The number
of type 2 triggers implemented is 2, which is the number that we can
find in the SiFive U54/U74 cores.

[1] https://github.com/riscv/riscv-debug-spec/raw/master/riscv-debug-stable.pdf

Changes in v3:
- drop riscv_trigger_init(), which will be moved to patch #5
- add riscv_trigger_init(), moved from patch #1 to this patch
- enable debug feature by default for all CPUs

Changes in v2:
- new patch: add debug state description
- use 0 instead of GETPC()
- change the config option to 'disabled' by default

Bin Meng (7):
  target/riscv: Add initial support for native debug
  target/riscv: machine: Add debug state description
  target/riscv: debug: Implement debug related TCGCPUOps
  target/riscv: cpu: Add a config option for native debug
  target/riscv: csr: Hook debug CSR read/write
  target/riscv: cpu: Enable native debug feature
  hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint()

 include/hw/core/tcg-cpu-ops.h |   1 +
 target/riscv/cpu.h            |   7 +
 target/riscv/debug.h          | 114 +++++++++
 target/riscv/cpu.c            |  14 ++
 target/riscv/csr.c            |  57 +++++
 target/riscv/debug.c          | 441 ++++++++++++++++++++++++++++++++++
 target/riscv/machine.c        |  33 +++
 target/riscv/meson.build      |   1 +
 8 files changed, 668 insertions(+)
 create mode 100644 target/riscv/debug.h
 create mode 100644 target/riscv/debug.c

-- 
2.25.1



^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v3 1/7] target/riscv: Add initial support for native debug
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
@ 2022-01-05  3:01 ` Bin Meng
  2022-01-05  3:01 ` [PATCH v3 2/7] target/riscv: machine: Add debug state description Bin Meng
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv

This adds initial support for the native debug via the Trigger Module,
as defined in the RISC-V Debug Specification [1].

Only "Address / Data Match" trigger (type 2) is implemented as of now,
which is mainly used for hardware breakpoint and watchpoint. The number
of type 2 triggers implemented is 2, which is the number that we can
find in the SiFive U54/U74 cores.

[1] https://github.com/riscv/riscv-debug-spec/raw/master/riscv-debug-stable.pdf

Signed-off-by: Bin Meng <bin.meng@windriver.com>

---

Changes in v3:
- drop riscv_trigger_init(), which will be moved to patch #5

 target/riscv/cpu.h       |   5 +
 target/riscv/debug.h     | 108 +++++++++++++
 target/riscv/debug.c     | 339 +++++++++++++++++++++++++++++++++++++++
 target/riscv/meson.build |   1 +
 4 files changed, 453 insertions(+)
 create mode 100644 target/riscv/debug.h
 create mode 100644 target/riscv/debug.c

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index dc10f27093..0f3b3a4219 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -98,6 +98,7 @@ typedef struct CPURISCVState CPURISCVState;
 
 #if !defined(CONFIG_USER_ONLY)
 #include "pmp.h"
+#include "debug.h"
 #endif
 
 #define RV_VLEN_MAX 1024
@@ -234,6 +235,10 @@ struct CPURISCVState {
     pmp_table_t pmp_state;
     target_ulong mseccfg;
 
+    /* trigger module */
+    target_ulong trigger_cur;
+    trigger_type2_t trigger_type2[TRIGGER_TYPE2_NUM];
+
     /* machine specific rdtime callback */
     uint64_t (*rdtime_fn)(uint32_t);
     uint32_t rdtime_fn_arg;
diff --git a/target/riscv/debug.h b/target/riscv/debug.h
new file mode 100644
index 0000000000..0a3fda6c72
--- /dev/null
+++ b/target/riscv/debug.h
@@ -0,0 +1,108 @@
+/*
+ * QEMU RISC-V Native Debug Support
+ *
+ * Copyright (c) 2022 Wind River Systems, Inc.
+ *
+ * Author:
+ *   Bin Meng <bin.meng@windriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef RISCV_DEBUG_H
+#define RISCV_DEBUG_H
+
+/* trigger indexes implemented */
+enum {
+    TRIGGER_TYPE2_IDX_0 = 0,
+    TRIGGER_TYPE2_IDX_1,
+    TRIGGER_TYPE2_NUM,
+    TRIGGER_NUM = TRIGGER_TYPE2_NUM
+};
+
+/* register index of tdata CSRs */
+enum {
+    TDATA1 = 0,
+    TDATA2,
+    TDATA3,
+    TDATA_NUM
+};
+
+typedef enum {
+    TRIGGER_TYPE_NO_EXIST = 0,      /* trigger does not exist */
+    TRIGGER_TYPE_AD_MATCH = 2,      /* address/data match trigger */
+    TRIGGER_TYPE_INST_CNT = 3,      /* instruction count trigger */
+    TRIGGER_TYPE_INT = 4,           /* interrupt trigger */
+    TRIGGER_TYPE_EXCP = 5,          /* exception trigger */
+    TRIGGER_TYPE_AD_MATCH6 = 6,     /* new address/data match trigger */
+    TRIGGER_TYPE_EXT_SRC = 7,       /* external source trigger */
+    TRIGGER_TYPE_UNAVAIL = 15       /* trigger exists, but unavailable */
+} trigger_type_t;
+
+typedef struct {
+    target_ulong mcontrol;
+    target_ulong maddress;
+    struct CPUBreakpoint *bp;
+    struct CPUWatchpoint *wp;
+} trigger_type2_t;
+
+/* tdata field masks */
+
+#define RV32_TYPE(t)    ((uint32_t)(t) << 28)
+#define RV32_TYPE_MASK  (0xf << 28)
+#define RV32_DMODE      BIT(27)
+#define RV64_TYPE(t)    ((uint64_t)(t) << 60)
+#define RV64_TYPE_MASK  (0xfULL << 60)
+#define RV64_DMODE      BIT_ULL(59)
+
+/* mcontrol field masks */
+
+#define TYPE2_LOAD      BIT(0)
+#define TYPE2_STORE     BIT(1)
+#define TYPE2_EXEC      BIT(2)
+#define TYPE2_U         BIT(3)
+#define TYPE2_S         BIT(4)
+#define TYPE2_M         BIT(6)
+#define TYPE2_MATCH     (0xf << 7)
+#define TYPE2_CHAIN     BIT(11)
+#define TYPE2_ACTION    (0xf << 12)
+#define TYPE2_SIZELO    (0x3 << 16)
+#define TYPE2_TIMING    BIT(18)
+#define TYPE2_SELECT    BIT(19)
+#define TYPE2_HIT       BIT(20)
+#define TYPE2_SIZEHI    (0x3 << 21) /* RV64 only */
+
+/* access size */
+enum {
+    SIZE_ANY = 0,
+    SIZE_1B,
+    SIZE_2B,
+    SIZE_4B,
+    SIZE_6B,
+    SIZE_8B,
+    SIZE_10B,
+    SIZE_12B,
+    SIZE_14B,
+    SIZE_16B,
+    SIZE_NUM = 16
+};
+
+bool tdata_available(CPURISCVState *env, int tdata_index);
+
+target_ulong tselect_csr_read(CPURISCVState *env);
+void tselect_csr_write(CPURISCVState *env, target_ulong val);
+
+target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index);
+void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val);
+
+#endif /* RISCV_DEBUG_H */
diff --git a/target/riscv/debug.c b/target/riscv/debug.c
new file mode 100644
index 0000000000..530e030007
--- /dev/null
+++ b/target/riscv/debug.c
@@ -0,0 +1,339 @@
+/*
+ * QEMU RISC-V Native Debug Support
+ *
+ * Copyright (c) 2022 Wind River Systems, Inc.
+ *
+ * Author:
+ *   Bin Meng <bin.meng@windriver.com>
+ *
+ * This provides the native debug support via the Trigger Module, as defined
+ * in the RISC-V Debug Specification:
+ * https://github.com/riscv/riscv-debug-spec/raw/master/riscv-debug-stable.pdf
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qapi/error.h"
+#include "cpu.h"
+#include "trace.h"
+#include "exec/exec-all.h"
+
+/*
+ * The following M-mode trigger CSRs are implemented:
+ *
+ * - tselect
+ * - tdata1
+ * - tdata2
+ * - tdata3
+ *
+ * We don't support writable 'type' field in the tdata1 register, so there is
+ * no need to implement the "tinfo" CSR.
+ *
+ * The following triggers are implemented:
+ *
+ * Index | Type |          tdata mapping | Description
+ * ------+------+------------------------+------------
+ *     0 |    2 |         tdata1, tdata2 | Address / Data Match
+ *     1 |    2 |         tdata1, tdata2 | Address / Data Match
+ */
+
+/* tdata availability of a trigger */
+typedef bool tdata_avail[TDATA_NUM];
+
+static tdata_avail tdata_mapping[TRIGGER_NUM] = {
+    [TRIGGER_TYPE2_IDX_0 ... TRIGGER_TYPE2_IDX_1] = { true, true, false },
+};
+
+/* only breakpoint size 1/2/4/8 supported */
+static int access_size[SIZE_NUM] = {
+    [SIZE_ANY] = 0,
+    [SIZE_1B]  = 1,
+    [SIZE_2B]  = 2,
+    [SIZE_4B]  = 4,
+    [SIZE_6B]  = -1,
+    [SIZE_8B]  = 8,
+    [6 ... 15] = -1,
+};
+
+static inline target_ulong trigger_type(CPURISCVState *env,
+                                        trigger_type_t type)
+{
+    target_ulong tdata1;
+
+    switch (riscv_cpu_mxl(env)) {
+    case MXL_RV32:
+        tdata1 = RV32_TYPE(type);
+        break;
+    case MXL_RV64:
+        tdata1 = RV64_TYPE(type);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    return tdata1;
+}
+
+bool tdata_available(CPURISCVState *env, int tdata_index)
+{
+    if (unlikely(tdata_index >= TDATA_NUM)) {
+        return false;
+    }
+
+    if (unlikely(env->trigger_cur >= TRIGGER_NUM)) {
+        return false;
+    }
+
+    return tdata_mapping[env->trigger_cur][tdata_index];
+}
+
+target_ulong tselect_csr_read(CPURISCVState *env)
+{
+    return env->trigger_cur;
+}
+
+void tselect_csr_write(CPURISCVState *env, target_ulong val)
+{
+    /* all target_ulong bits of tselect are implemented */
+    env->trigger_cur = val;
+}
+
+static target_ulong tdata1_validate(CPURISCVState *env, target_ulong val,
+                                    trigger_type_t t)
+{
+    uint32_t type, dmode;
+    target_ulong tdata1;
+
+    switch (riscv_cpu_mxl(env)) {
+    case MXL_RV32:
+        type = extract32(val, 28, 4);
+        dmode = extract32(val, 27, 1);
+        tdata1 = RV32_TYPE(t);
+        break;
+    case MXL_RV64:
+        type = extract64(val, 60, 4);
+        dmode = extract64(val, 59, 1);
+        tdata1 = RV64_TYPE(t);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    if (type != t) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "ignoring type write to tdata1 register\n");
+    }
+    if (dmode != 0) {
+        qemu_log_mask(LOG_UNIMP, "debug mode is not supported\n");
+    }
+
+    return tdata1;
+}
+
+static inline void warn_always_zero_bit(target_ulong val, target_ulong mask,
+                                        const char *msg)
+{
+    if (val & mask) {
+        qemu_log_mask(LOG_UNIMP, "%s bit is always zero\n", msg);
+    }
+}
+
+static uint32_t type2_breakpoint_size(CPURISCVState *env, target_ulong ctrl)
+{
+    uint32_t size, sizelo, sizehi = 0;
+
+    if (riscv_cpu_mxl(env) == MXL_RV64) {
+        sizehi = extract32(ctrl, 21, 2);
+    }
+    sizelo = extract32(ctrl, 16, 2);
+    size = (sizehi << 2) | sizelo;
+
+    return size;
+}
+
+static inline bool type2_breakpoint_enabled(target_ulong ctrl)
+{
+    bool mode = !!(ctrl & (TYPE2_U | TYPE2_S | TYPE2_M));
+    bool rwx = !!(ctrl & (TYPE2_LOAD | TYPE2_STORE | TYPE2_EXEC));
+
+    return mode && rwx;
+}
+
+static target_ulong type2_mcontrol_validate(CPURISCVState *env,
+                                            target_ulong ctrl)
+{
+    target_ulong val;
+    uint32_t size;
+
+    /* validate the generic part first */
+    val = tdata1_validate(env, ctrl, TRIGGER_TYPE_AD_MATCH);
+
+    /* validate unimplemented (always zero) bits */
+    warn_always_zero_bit(ctrl, TYPE2_MATCH, "match");
+    warn_always_zero_bit(ctrl, TYPE2_CHAIN, "chain");
+    warn_always_zero_bit(ctrl, TYPE2_ACTION, "action");
+    warn_always_zero_bit(ctrl, TYPE2_TIMING, "timing");
+    warn_always_zero_bit(ctrl, TYPE2_SELECT, "select");
+    warn_always_zero_bit(ctrl, TYPE2_HIT, "hit");
+
+    /* validate size encoding */
+    size = type2_breakpoint_size(env, ctrl);
+    if (access_size[size] == -1) {
+        qemu_log_mask(LOG_UNIMP, "access size %d is not supported, using SIZE_ANY\n",
+                      size);
+    } else {
+        val |= (ctrl & TYPE2_SIZELO);
+        if (riscv_cpu_mxl(env) == MXL_RV64) {
+            val |= (ctrl & TYPE2_SIZEHI);
+        }
+    }
+
+    /* keep the mode and attribute bits */
+    val |= (ctrl & (TYPE2_U | TYPE2_S | TYPE2_M |
+                    TYPE2_LOAD | TYPE2_STORE | TYPE2_EXEC));
+
+    return val;
+}
+
+static void type2_breakpoint_insert(CPURISCVState *env, target_ulong index)
+{
+    target_ulong ctrl = env->trigger_type2[index].mcontrol;
+    target_ulong addr = env->trigger_type2[index].maddress;
+    bool enabled = type2_breakpoint_enabled(ctrl);
+    CPUState *cs = env_cpu(env);
+    int flags = BP_CPU | BP_STOP_BEFORE_ACCESS;
+    uint32_t size;
+
+    if (!enabled) {
+        return;
+    }
+
+    if (ctrl & TYPE2_EXEC) {
+        cpu_breakpoint_insert(cs, addr, flags, &env->trigger_type2[index].bp);
+    }
+
+    if (ctrl & TYPE2_LOAD) {
+        flags |= BP_MEM_READ;
+    }
+    if (ctrl & TYPE2_STORE) {
+        flags |= BP_MEM_WRITE;
+    }
+
+    if (flags & BP_MEM_ACCESS) {
+        size = type2_breakpoint_size(env, ctrl);
+        if (size != 0) {
+            cpu_watchpoint_insert(cs, addr, size, flags,
+                                  &env->trigger_type2[index].wp);
+        } else {
+            cpu_watchpoint_insert(cs, addr, 8, flags,
+                                  &env->trigger_type2[index].wp);
+        }
+    }
+}
+
+static void type2_breakpoint_remove(CPURISCVState *env, target_ulong index)
+{
+    CPUState *cs = env_cpu(env);
+
+    if (env->trigger_type2[index].bp) {
+        cpu_breakpoint_remove_by_ref(cs, env->trigger_type2[index].bp);
+        env->trigger_type2[index].bp = NULL;
+    }
+
+    if (env->trigger_type2[index].wp) {
+        cpu_watchpoint_remove_by_ref(cs, env->trigger_type2[index].wp);
+        env->trigger_type2[index].wp = NULL;
+    }
+}
+
+static target_ulong type2_reg_read(CPURISCVState *env,
+                                   target_ulong trigger_index, int tdata_index)
+{
+    uint32_t index = trigger_index - TRIGGER_TYPE2_IDX_0;
+    target_ulong tdata;
+
+    switch (tdata_index) {
+    case TDATA1:
+        tdata = env->trigger_type2[index].mcontrol;
+        break;
+    case TDATA2:
+        tdata = env->trigger_type2[index].maddress;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    return tdata;
+}
+
+static void type2_reg_write(CPURISCVState *env, target_ulong trigger_index,
+                            int tdata_index, target_ulong val)
+{
+    uint32_t index = trigger_index - TRIGGER_TYPE2_IDX_0;
+    target_ulong new_val;
+
+    switch (tdata_index) {
+    case TDATA1:
+        new_val = type2_mcontrol_validate(env, val);
+        if (new_val != env->trigger_type2[index].mcontrol) {
+            env->trigger_type2[index].mcontrol = new_val;
+            type2_breakpoint_remove(env, index);
+            type2_breakpoint_insert(env, index);
+        }
+        break;
+    case TDATA2:
+        if (val != env->trigger_type2[index].maddress) {
+            env->trigger_type2[index].maddress = val;
+            type2_breakpoint_remove(env, index);
+            type2_breakpoint_insert(env, index);
+        }
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    return;
+}
+
+typedef target_ulong (*tdata_read_func)(CPURISCVState *env,
+                                        target_ulong trigger_index,
+                                        int tdata_index);
+
+static tdata_read_func trigger_read_funcs[TRIGGER_NUM] = {
+    [TRIGGER_TYPE2_IDX_0 ... TRIGGER_TYPE2_IDX_1] = type2_reg_read,
+};
+
+typedef void (*tdata_write_func)(CPURISCVState *env,
+                                 target_ulong trigger_index,
+                                 int tdata_index,
+                                 target_ulong val);
+
+static tdata_write_func trigger_write_funcs[TRIGGER_NUM] = {
+    [TRIGGER_TYPE2_IDX_0 ... TRIGGER_TYPE2_IDX_1] = type2_reg_write,
+};
+
+target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
+{
+    tdata_read_func read_func = trigger_read_funcs[env->trigger_cur];
+
+    return read_func(env, env->trigger_cur, tdata_index);
+}
+
+void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val)
+{
+    tdata_write_func write_func = trigger_write_funcs[env->trigger_cur];
+
+    return write_func(env, env->trigger_cur, tdata_index, val);
+}
diff --git a/target/riscv/meson.build b/target/riscv/meson.build
index d5e0bc93ea..966d97237a 100644
--- a/target/riscv/meson.build
+++ b/target/riscv/meson.build
@@ -24,6 +24,7 @@ riscv_softmmu_ss = ss.source_set()
 riscv_softmmu_ss.add(files(
   'arch_dump.c',
   'pmp.c',
+  'debug.c',
   'monitor.c',
   'machine.c'
 ))
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 2/7] target/riscv: machine: Add debug state description
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
  2022-01-05  3:01 ` [PATCH v3 1/7] target/riscv: Add initial support for native debug Bin Meng
@ 2022-01-05  3:01 ` Bin Meng
  2022-01-05  3:01 ` [PATCH v3 3/7] target/riscv: debug: Implement debug related TCGCPUOps Bin Meng
                   ` (4 subsequent siblings)
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv; +Cc: Alistair Francis

Add a subsection to machine.c to migrate debug CSR state.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

---

(no changes since v2)

Changes in v2:
- new patch: add debug state description

 target/riscv/machine.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index ad8248ebfd..25aa3b38f7 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -164,6 +164,38 @@ static const VMStateDescription vmstate_pointermasking = {
     }
 };
 
+static bool debug_needed(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    CPURISCVState *env = &cpu->env;
+
+    return riscv_feature(env, RISCV_FEATURE_DEBUG);
+}
+
+static const VMStateDescription vmstate_debug_type2 = {
+    .name = "cpu/debug/type2",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINTTL(mcontrol, trigger_type2_t),
+        VMSTATE_UINTTL(maddress, trigger_type2_t),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_debug = {
+    .name = "cpu/debug",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = debug_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINTTL(env.trigger_cur, RISCVCPU),
+        VMSTATE_STRUCT_ARRAY(env.trigger_type2, RISCVCPU, TRIGGER_TYPE2_NUM,
+                             0, vmstate_debug_type2, trigger_type2_t),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_riscv_cpu = {
     .name = "cpu",
     .version_id = 3,
@@ -218,6 +250,7 @@ const VMStateDescription vmstate_riscv_cpu = {
         &vmstate_hyper,
         &vmstate_vector,
         &vmstate_pointermasking,
+        &vmstate_debug,
         NULL
     }
 };
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 3/7] target/riscv: debug: Implement debug related TCGCPUOps
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
  2022-01-05  3:01 ` [PATCH v3 1/7] target/riscv: Add initial support for native debug Bin Meng
  2022-01-05  3:01 ` [PATCH v3 2/7] target/riscv: machine: Add debug state description Bin Meng
@ 2022-01-05  3:01 ` Bin Meng
  2022-01-05  3:01 ` [PATCH v3 4/7] target/riscv: cpu: Add a config option for native debug Bin Meng
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv; +Cc: Alistair Francis

Implement .debug_excp_handler, .debug_check_{breakpoint, watchpoint}
TCGCPUOps and hook them into riscv_tcg_ops.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

---

(no changes since v2)

Changes in v2:
- use 0 instead of GETPC()

 target/riscv/debug.h |  4 +++
 target/riscv/cpu.c   |  3 ++
 target/riscv/debug.c | 75 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+)

diff --git a/target/riscv/debug.h b/target/riscv/debug.h
index 0a3fda6c72..d0f63e2414 100644
--- a/target/riscv/debug.h
+++ b/target/riscv/debug.h
@@ -105,4 +105,8 @@ void tselect_csr_write(CPURISCVState *env, target_ulong val);
 target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index);
 void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val);
 
+void riscv_cpu_debug_excp_handler(CPUState *cs);
+bool riscv_cpu_debug_check_breakpoint(CPUState *cs);
+bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
+
 #endif /* RISCV_DEBUG_H */
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 6ef3314bce..3aa07bc019 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -705,6 +705,9 @@ static const struct TCGCPUOps riscv_tcg_ops = {
     .do_interrupt = riscv_cpu_do_interrupt,
     .do_transaction_failed = riscv_cpu_do_transaction_failed,
     .do_unaligned_access = riscv_cpu_do_unaligned_access,
+    .debug_excp_handler = riscv_cpu_debug_excp_handler,
+    .debug_check_breakpoint = riscv_cpu_debug_check_breakpoint,
+    .debug_check_watchpoint = riscv_cpu_debug_check_watchpoint,
 #endif /* !CONFIG_USER_ONLY */
 };
 
diff --git a/target/riscv/debug.c b/target/riscv/debug.c
index 530e030007..7760c4611f 100644
--- a/target/riscv/debug.c
+++ b/target/riscv/debug.c
@@ -337,3 +337,78 @@ void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val)
 
     return write_func(env, env->trigger_cur, tdata_index, val);
 }
+
+void riscv_cpu_debug_excp_handler(CPUState *cs)
+{
+    RISCVCPU *cpu = RISCV_CPU(cs);
+    CPURISCVState *env = &cpu->env;
+
+    if (cs->watchpoint_hit) {
+        if (cs->watchpoint_hit->flags & BP_CPU) {
+            cs->watchpoint_hit = NULL;
+            riscv_raise_exception(env, RISCV_EXCP_BREAKPOINT, 0);
+        }
+    } else {
+        if (cpu_breakpoint_test(cs, env->pc, BP_CPU)) {
+            riscv_raise_exception(env, RISCV_EXCP_BREAKPOINT, 0);
+        }
+    }
+}
+
+bool riscv_cpu_debug_check_breakpoint(CPUState *cs)
+{
+    RISCVCPU *cpu = RISCV_CPU(cs);
+    CPURISCVState *env = &cpu->env;
+    CPUBreakpoint *bp;
+    target_ulong ctrl;
+    target_ulong pc;
+    int i;
+
+    QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
+        for (i = 0; i < TRIGGER_TYPE2_NUM; i++) {
+            ctrl = env->trigger_type2[i].mcontrol;
+            pc = env->trigger_type2[i].maddress;
+
+            if ((ctrl & TYPE2_EXEC) && (bp->pc == pc)) {
+                /* check U/S/M bit against current privilege level */
+                if ((ctrl >> 3) & BIT(env->priv)) {
+                    return true;
+                }
+            }
+        }
+    }
+
+    return false;
+}
+
+bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)
+{
+    RISCVCPU *cpu = RISCV_CPU(cs);
+    CPURISCVState *env = &cpu->env;
+    target_ulong ctrl;
+    target_ulong addr;
+    int flags;
+    int i;
+
+    for (i = 0; i < TRIGGER_TYPE2_NUM; i++) {
+        ctrl = env->trigger_type2[i].mcontrol;
+        addr = env->trigger_type2[i].maddress;
+        flags = 0;
+
+        if (ctrl & TYPE2_LOAD) {
+            flags |= BP_MEM_READ;
+        }
+        if (ctrl & TYPE2_STORE) {
+            flags |= BP_MEM_WRITE;
+        }
+
+        if ((wp->flags & flags) && (wp->vaddr == addr)) {
+            /* check U/S/M bit against current privilege level */
+            if ((ctrl >> 3) & BIT(env->priv)) {
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 4/7] target/riscv: cpu: Add a config option for native debug
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
                   ` (2 preceding siblings ...)
  2022-01-05  3:01 ` [PATCH v3 3/7] target/riscv: debug: Implement debug related TCGCPUOps Bin Meng
@ 2022-01-05  3:01 ` Bin Meng
  2022-01-05  3:01 ` [PATCH v3 5/7] target/riscv: csr: Hook debug CSR read/write Bin Meng
                   ` (2 subsequent siblings)
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv; +Cc: Alistair Francis

Add a config option to enable support for native M-mode debug.
This is disabled by default and can be enabled with 'debug=true'.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

---

(no changes since v2)

Changes in v2:
- change the config option to 'disabled' by default

 target/riscv/cpu.h | 2 ++
 target/riscv/cpu.c | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0f3b3a4219..35445bbc86 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -75,6 +75,7 @@ enum {
     RISCV_FEATURE_MMU,
     RISCV_FEATURE_PMP,
     RISCV_FEATURE_EPMP,
+    RISCV_FEATURE_DEBUG,
     RISCV_FEATURE_MISA
 };
 
@@ -332,6 +333,7 @@ struct RISCVCPU {
         bool mmu;
         bool pmp;
         bool epmp;
+        bool debug;
         uint64_t resetvec;
     } cfg;
 };
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 3aa07bc019..d36c31ce9a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -448,6 +448,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         }
     }
 
+    if (cpu->cfg.debug) {
+        set_feature(env, RISCV_FEATURE_DEBUG);
+    }
+
     set_resetvec(env, cpu->cfg.resetvec);
 
     /* Validate that MISA_MXL is set properly. */
@@ -634,6 +638,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("Zfhmin", RISCVCPU, cfg.ext_zfhmin, false),
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
+    DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, false),
 
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
     DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 5/7] target/riscv: csr: Hook debug CSR read/write
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
                   ` (3 preceding siblings ...)
  2022-01-05  3:01 ` [PATCH v3 4/7] target/riscv: cpu: Add a config option for native debug Bin Meng
@ 2022-01-05  3:01 ` Bin Meng
  2022-01-05  3:01 ` [PATCH v3 6/7] target/riscv: cpu: Enable native debug feature Bin Meng
  2022-01-05  3:01   ` Bin Meng
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv

This adds debug CSR read/write support to the RISC-V CSR RW table.

Signed-off-by: Bin Meng <bin.meng@windriver.com>

---

Changes in v3:
- add riscv_trigger_init(), moved from patch #1 to this patch

 target/riscv/debug.h |  2 ++
 target/riscv/cpu.c   |  6 +++++
 target/riscv/csr.c   | 57 ++++++++++++++++++++++++++++++++++++++++++++
 target/riscv/debug.c | 27 +++++++++++++++++++++
 4 files changed, 92 insertions(+)

diff --git a/target/riscv/debug.h b/target/riscv/debug.h
index d0f63e2414..f4da2db35d 100644
--- a/target/riscv/debug.h
+++ b/target/riscv/debug.h
@@ -109,4 +109,6 @@ void riscv_cpu_debug_excp_handler(CPUState *cs);
 bool riscv_cpu_debug_check_breakpoint(CPUState *cs);
 bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
 
+void riscv_trigger_init(CPURISCVState *env);
+
 #endif /* RISCV_DEBUG_H */
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index d36c31ce9a..17dcc3c14f 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -575,6 +575,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
 
     riscv_cpu_register_gdb_regs_for_features(cs);
 
+#ifndef CONFIG_USER_ONLY
+    if (riscv_feature(env, RISCV_FEATURE_DEBUG)) {
+        riscv_trigger_init(env);
+    }
+#endif
+
     qemu_init_vcpu(cs);
     cpu_reset(cs);
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 146447eac5..189b9cc8c6 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -220,6 +220,15 @@ static RISCVException epmp(CPURISCVState *env, int csrno)
 
     return RISCV_EXCP_ILLEGAL_INST;
 }
+
+static RISCVException debug(CPURISCVState *env, int csrno)
+{
+    if (riscv_feature(env, RISCV_FEATURE_DEBUG)) {
+        return RISCV_EXCP_NONE;
+    }
+
+    return RISCV_EXCP_ILLEGAL_INST;
+}
 #endif
 
 /* User Floating-Point CSRs */
@@ -1464,6 +1473,48 @@ static RISCVException write_pmpaddr(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
+static RISCVException read_tselect(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
+{
+    *val = tselect_csr_read(env);
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_tselect(CPURISCVState *env, int csrno,
+                                    target_ulong val)
+{
+    tselect_csr_write(env, val);
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException read_tdata(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
+{
+    /* return 0 in tdata1 to end the trigger enumeration */
+    if (env->trigger_cur >= TRIGGER_NUM && csrno == CSR_TDATA1) {
+        *val = 0;
+        return RISCV_EXCP_NONE;
+    }
+
+    if (!tdata_available(env, csrno - CSR_TDATA1)) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    *val = tdata_csr_read(env, csrno - CSR_TDATA1);
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_tdata(CPURISCVState *env, int csrno,
+                                  target_ulong val)
+{
+    if (!tdata_available(env, csrno - CSR_TDATA1)) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    tdata_csr_write(env, csrno - CSR_TDATA1, val);
+    return RISCV_EXCP_NONE;
+}
+
 /*
  * Functions to access Pointer Masking feature registers
  * We have to check if current priv lvl could modify
@@ -1962,6 +2013,12 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_PMPADDR14] =  { "pmpaddr14", pmp, read_pmpaddr, write_pmpaddr },
     [CSR_PMPADDR15] =  { "pmpaddr15", pmp, read_pmpaddr, write_pmpaddr },
 
+    /* Debug CSRs */
+    [CSR_TSELECT]   =  { "tselect", debug, read_tselect, write_tselect },
+    [CSR_TDATA1]    =  { "tdata1",  debug, read_tdata,   write_tdata   },
+    [CSR_TDATA2]    =  { "tdata2",  debug, read_tdata,   write_tdata   },
+    [CSR_TDATA3]    =  { "tdata3",  debug, read_tdata,   write_tdata   },
+
     /* User Pointer Masking */
     [CSR_UMTE]    =    { "umte",    pointer_masking, read_umte,    write_umte    },
     [CSR_UPMMASK] =    { "upmmask", pointer_masking, read_upmmask, write_upmmask },
diff --git a/target/riscv/debug.c b/target/riscv/debug.c
index 7760c4611f..041a0d3a89 100644
--- a/target/riscv/debug.c
+++ b/target/riscv/debug.c
@@ -412,3 +412,30 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)
 
     return false;
 }
+
+void riscv_trigger_init(CPURISCVState *env)
+{
+    target_ulong type2 = trigger_type(env, TRIGGER_TYPE_AD_MATCH);
+    int i;
+
+    /* type 2 triggers */
+    for (i = 0; i < TRIGGER_TYPE2_NUM; i++) {
+        /*
+         * type = TRIGGER_TYPE_AD_MATCH
+         * dmode = 0 (both debug and M-mode can write tdata)
+         * maskmax = 0 (unimplemented, always 0)
+         * sizehi = 0 (match against any size, RV64 only)
+         * hit = 0 (unimplemented, always 0)
+         * select = 0 (always 0, perform match on address)
+         * timing = 0 (always 0, trigger before instruction)
+         * sizelo = 0 (match against any size)
+         * action = 0 (always 0, raise a breakpoint exception)
+         * chain = 0 (unimplemented, always 0)
+         * match = 0 (always 0, when any compare value equals tdata2)
+         */
+        env->trigger_type2[i].mcontrol = type2;
+        env->trigger_type2[i].maddress = 0;
+        env->trigger_type2[i].bp = NULL;
+        env->trigger_type2[i].wp = NULL;
+    }
+}
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 6/7] target/riscv: cpu: Enable native debug feature
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
                   ` (4 preceding siblings ...)
  2022-01-05  3:01 ` [PATCH v3 5/7] target/riscv: csr: Hook debug CSR read/write Bin Meng
@ 2022-01-05  3:01 ` Bin Meng
  2022-01-05  3:01   ` Bin Meng
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv

Turn on native debug feature by default for all CPUs.

Signed-off-by: Bin Meng <bin.meng@windriver.com>

---

Changes in v3:
- enable debug feature by default for all CPUs

 target/riscv/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 17dcc3c14f..17444b458f 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -644,7 +644,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("Zfhmin", RISCVCPU, cfg.ext_zfhmin, false),
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
-    DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, false),
+    DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
 
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
     DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 7/7] hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint()
  2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
@ 2022-01-05  3:01   ` Bin Meng
  2022-01-05  3:01 ` [PATCH v3 2/7] target/riscv: machine: Add debug state description Bin Meng
                     ` (5 subsequent siblings)
  6 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv
  Cc: Alistair Francis, Richard Henderson

This is now used by RISC-V as well. Update the comments.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

---

(no changes since v1)

 include/hw/core/tcg-cpu-ops.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h
index e13898553a..f98671ff32 100644
--- a/include/hw/core/tcg-cpu-ops.h
+++ b/include/hw/core/tcg-cpu-ops.h
@@ -90,6 +90,7 @@ struct TCGCPUOps {
     /**
      * @debug_check_watchpoint: return true if the architectural
      * watchpoint whose address has matched should really fire, used by ARM
+     * and RISC-V
      */
     bool (*debug_check_watchpoint)(CPUState *cpu, CPUWatchpoint *wp);
 
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 7/7] hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint()
@ 2022-01-05  3:01   ` Bin Meng
  0 siblings, 0 replies; 9+ messages in thread
From: Bin Meng @ 2022-01-05  3:01 UTC (permalink / raw)
  To: Alistair Francis, qemu-devel, qemu-riscv
  Cc: Richard Henderson, Alistair Francis

This is now used by RISC-V as well. Update the comments.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

---

(no changes since v1)

 include/hw/core/tcg-cpu-ops.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h
index e13898553a..f98671ff32 100644
--- a/include/hw/core/tcg-cpu-ops.h
+++ b/include/hw/core/tcg-cpu-ops.h
@@ -90,6 +90,7 @@ struct TCGCPUOps {
     /**
      * @debug_check_watchpoint: return true if the architectural
      * watchpoint whose address has matched should really fire, used by ARM
+     * and RISC-V
      */
     bool (*debug_check_watchpoint)(CPUState *cpu, CPUWatchpoint *wp);
 
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2022-01-05  3:22 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-05  3:01 [PATCH v3 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs Bin Meng
2022-01-05  3:01 ` [PATCH v3 1/7] target/riscv: Add initial support for native debug Bin Meng
2022-01-05  3:01 ` [PATCH v3 2/7] target/riscv: machine: Add debug state description Bin Meng
2022-01-05  3:01 ` [PATCH v3 3/7] target/riscv: debug: Implement debug related TCGCPUOps Bin Meng
2022-01-05  3:01 ` [PATCH v3 4/7] target/riscv: cpu: Add a config option for native debug Bin Meng
2022-01-05  3:01 ` [PATCH v3 5/7] target/riscv: csr: Hook debug CSR read/write Bin Meng
2022-01-05  3:01 ` [PATCH v3 6/7] target/riscv: cpu: Enable native debug feature Bin Meng
2022-01-05  3:01 ` [PATCH v3 7/7] hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint() Bin Meng
2022-01-05  3:01   ` Bin Meng

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