Merge tag 'pull-maintainer-updates-060324-1' of https://gitlab.com/stsquad/qemu into staging

maintainer updates (tests, gdbstub, plugins):

  - expand QOS_PATH_MAX_ELEMENT_SIZE to avoid LTO issues
  - support fork-follow-mode in gdbstub
  - new thread-safe scoreboard API for TCG plugins
  - suppress showing opcodes in plugin disassembly

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# gpg: Signature made Wed 06 Mar 2024 12:38:18 GMT
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* tag 'pull-maintainer-updates-060324-1' of https://gitlab.com/stsquad/qemu: (29 commits)
  target/riscv: honour show_opcodes when disassembling
  target/loongarch: honour show_opcodes when disassembling
  disas/hppa: honour show_opcodes
  disas: introduce show_opcodes
  plugins: cleanup codepath for previous inline operation
  plugins: remove non per_vcpu inline operation from API
  contrib/plugins/howvec: migrate to new per_vcpu API
  contrib/plugins/hotblocks: migrate to new per_vcpu API
  tests/plugin/bb: migrate to new per_vcpu API
  tests/plugin/insn: migrate to new per_vcpu API
  tests/plugin/mem: migrate to new per_vcpu API
  tests/plugin: add test plugin for inline operations
  plugins: add inline operation per vcpu
  plugins: implement inline operation relative to cpu_index
  plugins: define qemu_plugin_u64
  plugins: scoreboard API
  tests/tcg: Add two follow-fork-mode tests
  gdbstub: Implement follow-fork-mode child
  gdbstub: Introduce gdb_handle_detach_user()
  gdbstub: Introduce gdb_handle_set_thread_user()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 173 insertions, 36 deletions

diff --git a/plugins/api.c b/plugins/api.c
index 81f43c9ce8..8fa5a600ac 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -101,12 +101,15 @@ void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
     }
 }
 
-void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
-                                              enum qemu_plugin_op op,
-                                              void *ptr, uint64_t imm)
+void qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu(
+    struct qemu_plugin_tb *tb,
+    enum qemu_plugin_op op,
+    qemu_plugin_u64 entry,
+    uint64_t imm)
 {
     if (!tb->mem_only) {
-        plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
+        plugin_register_inline_op_on_entry(
+            &tb->cbs[PLUGIN_CB_INLINE], 0, op, entry, imm);
     }
 }
 
@@ -125,13 +128,15 @@ void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
     }
 }
 
-void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
-                                                enum qemu_plugin_op op,
-                                                void *ptr, uint64_t imm)
+void qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu(
+    struct qemu_plugin_insn *insn,
+    enum qemu_plugin_op op,
+    qemu_plugin_u64 entry,
+    uint64_t imm)
 {
     if (!insn->mem_only) {
-        plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
-                                  0, op, ptr, imm);
+        plugin_register_inline_op_on_entry(
+            &insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE], 0, op, entry, imm);
     }
 }
 
@@ -147,16 +152,18 @@ void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
                                       void *udata)
 {
     plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
-                                    cb, flags, rw, udata);
+                                cb, flags, rw, udata);
 }
 
-void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
-                                          enum qemu_plugin_mem_rw rw,
-                                          enum qemu_plugin_op op, void *ptr,
-                                          uint64_t imm)
+void qemu_plugin_register_vcpu_mem_inline_per_vcpu(
+    struct qemu_plugin_insn *insn,
+    enum qemu_plugin_mem_rw rw,
+    enum qemu_plugin_op op,
+    qemu_plugin_u64 entry,
+    uint64_t imm)
 {
-    plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
-                              rw, op, ptr, imm);
+    plugin_register_inline_op_on_entry(
+        &insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE], rw, op, entry, imm);
 }
 
 void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
@@ -378,7 +385,7 @@ const char *qemu_plugin_path_to_binary(void)
 {
     char *path = NULL;
 #ifdef CONFIG_USER_ONLY
-    TaskState *ts = (TaskState *) current_cpu->opaque;
+    TaskState *ts = get_task_state(current_cpu);
     path = g_strdup(ts->bprm->filename);
 #endif
     return path;
@@ -388,7 +395,7 @@ uint64_t qemu_plugin_start_code(void)
 {
     uint64_t start = 0;
 #ifdef CONFIG_USER_ONLY
-    TaskState *ts = (TaskState *) current_cpu->opaque;
+    TaskState *ts = get_task_state(current_cpu);
     start = ts->info->start_code;
 #endif
     return start;
@@ -398,7 +405,7 @@ uint64_t qemu_plugin_end_code(void)
 {
     uint64_t end = 0;
 #ifdef CONFIG_USER_ONLY
-    TaskState *ts = (TaskState *) current_cpu->opaque;
+    TaskState *ts = get_task_state(current_cpu);
     end = ts->info->end_code;
 #endif
     return end;
@@ -408,7 +415,7 @@ uint64_t qemu_plugin_entry_code(void)
 {
     uint64_t entry = 0;
 #ifdef CONFIG_USER_ONLY
-    TaskState *ts = (TaskState *) current_cpu->opaque;
+    TaskState *ts = get_task_state(current_cpu);
     entry = ts->info->entry;
 #endif
     return entry;
@@ -465,3 +472,56 @@ int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf)
 
     return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg));
 }
+
+struct qemu_plugin_scoreboard *qemu_plugin_scoreboard_new(size_t element_size)
+{
+    return plugin_scoreboard_new(element_size);
+}
+
+void qemu_plugin_scoreboard_free(struct qemu_plugin_scoreboard *score)
+{
+    plugin_scoreboard_free(score);
+}
+
+void *qemu_plugin_scoreboard_find(struct qemu_plugin_scoreboard *score,
+                                  unsigned int vcpu_index)
+{
+    g_assert(vcpu_index < qemu_plugin_num_vcpus());
+    /* we can't use g_array_index since entry size is not statically known */
+    char *base_ptr = score->data->data;
+    return base_ptr + vcpu_index * g_array_get_element_size(score->data);
+}
+
+static uint64_t *plugin_u64_address(qemu_plugin_u64 entry,
+                                    unsigned int vcpu_index)
+{
+    char *ptr = qemu_plugin_scoreboard_find(entry.score, vcpu_index);
+    return (uint64_t *)(ptr + entry.offset);
+}
+
+void qemu_plugin_u64_add(qemu_plugin_u64 entry, unsigned int vcpu_index,
+                         uint64_t added)
+{
+    *plugin_u64_address(entry, vcpu_index) += added;
+}
+
+uint64_t qemu_plugin_u64_get(qemu_plugin_u64 entry,
+                             unsigned int vcpu_index)
+{
+    return *plugin_u64_address(entry, vcpu_index);
+}
+
+void qemu_plugin_u64_set(qemu_plugin_u64 entry, unsigned int vcpu_index,
+                         uint64_t val)
+{
+    *plugin_u64_address(entry, vcpu_index) = val;
+}
+
+uint64_t qemu_plugin_u64_sum(qemu_plugin_u64 entry)
+{
+    uint64_t total = 0;
+    for (int i = 0, n = qemu_plugin_num_vcpus(); i < n; ++i) {
+        total += qemu_plugin_u64_get(entry, i);
+    }
+    return total;
+}
diff --git a/plugins/core.c b/plugins/core.c
index 2db4d31354..11ca20e626 100644
--- a/plugins/core.c
+++ b/plugins/core.c
@@ -18,6 +18,7 @@
 #include "qemu/lockable.h"
 #include "qemu/option.h"
 #include "qemu/plugin.h"
+#include "qemu/queue.h"
 #include "qemu/rcu_queue.h"
 #include "qemu/xxhash.h"
 #include "qemu/rcu.h"
@@ -215,6 +216,35 @@ CPUPluginState *qemu_plugin_create_vcpu_state(void)
     return g_new0(CPUPluginState, 1);
 }
 
+static void plugin_grow_scoreboards__locked(CPUState *cpu)
+{
+    if (cpu->cpu_index < plugin.scoreboard_alloc_size) {
+        return;
+    }
+
+    bool need_realloc = FALSE;
+    while (cpu->cpu_index >= plugin.scoreboard_alloc_size) {
+        plugin.scoreboard_alloc_size *= 2;
+        need_realloc = TRUE;
+    }
+
+
+    if (!need_realloc || QLIST_EMPTY(&plugin.scoreboards)) {
+        /* nothing to do, we just updated sizes for future scoreboards */
+        return;
+    }
+
+    /* cpus must be stopped, as tb might still use an existing scoreboard. */
+    start_exclusive();
+    struct qemu_plugin_scoreboard *score;
+    QLIST_FOREACH(score, &plugin.scoreboards, entry) {
+        g_array_set_size(score->data, plugin.scoreboard_alloc_size);
+    }
+    /* force all tb to be flushed, as scoreboard pointers were changed. */
+    tb_flush(cpu);
+    end_exclusive();
+}
+
 void qemu_plugin_vcpu_init_hook(CPUState *cpu)
 {
     bool success;
@@ -225,6 +255,7 @@ void qemu_plugin_vcpu_init_hook(CPUState *cpu)
     success = g_hash_table_insert(plugin.cpu_ht, &cpu->cpu_index,
                                   &cpu->cpu_index);
     g_assert(success);
+    plugin_grow_scoreboards__locked(cpu);
     qemu_rec_mutex_unlock(&plugin.lock);
 
     plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_INIT);
@@ -285,17 +316,19 @@ static struct qemu_plugin_dyn_cb *plugin_get_dyn_cb(GArray **arr)
     return &g_array_index(cbs, struct qemu_plugin_dyn_cb, cbs->len - 1);
 }
 
-void plugin_register_inline_op(GArray **arr,
-                               enum qemu_plugin_mem_rw rw,
-                               enum qemu_plugin_op op, void *ptr,
-                               uint64_t imm)
+void plugin_register_inline_op_on_entry(GArray **arr,
+                                        enum qemu_plugin_mem_rw rw,
+                                        enum qemu_plugin_op op,
+                                        qemu_plugin_u64 entry,
+                                        uint64_t imm)
 {
     struct qemu_plugin_dyn_cb *dyn_cb;
 
     dyn_cb = plugin_get_dyn_cb(arr);
-    dyn_cb->userp = ptr;
+    dyn_cb->userp = NULL;
     dyn_cb->type = PLUGIN_CB_INLINE;
     dyn_cb->rw = rw;
+    dyn_cb->inline_insn.entry = entry;
     dyn_cb->inline_insn.op = op;
     dyn_cb->inline_insn.imm = imm;
 }
@@ -443,9 +476,13 @@ void qemu_plugin_flush_cb(void)
     plugin_cb__simple(QEMU_PLUGIN_EV_FLUSH);
 }
 
-void exec_inline_op(struct qemu_plugin_dyn_cb *cb)
+void exec_inline_op(struct qemu_plugin_dyn_cb *cb, int cpu_index)
 {
-    uint64_t *val = cb->userp;
+    char *ptr = cb->inline_insn.entry.score->data->data;
+    size_t elem_size = g_array_get_element_size(
+        cb->inline_insn.entry.score->data);
+    size_t offset = cb->inline_insn.entry.offset;
+    uint64_t *val = (uint64_t *)(ptr + offset + cpu_index * elem_size);
 
     switch (cb->inline_insn.op) {
     case QEMU_PLUGIN_INLINE_ADD_U64:
@@ -478,7 +515,7 @@ void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr,
                            vaddr, cb->userp);
             break;
         case PLUGIN_CB_INLINE:
-            exec_inline_op(cb);
+            exec_inline_op(cb, cpu->cpu_index);
             break;
         default:
             g_assert_not_reached();
@@ -578,6 +615,8 @@ static void __attribute__((__constructor__)) plugin_init(void)
     qemu_rec_mutex_init(&plugin.lock);
     plugin.id_ht = g_hash_table_new(g_int64_hash, g_int64_equal);
     plugin.cpu_ht = g_hash_table_new(g_int_hash, g_int_equal);
+    QLIST_INIT(&plugin.scoreboards);
+    plugin.scoreboard_alloc_size = 16; /* avoid frequent reallocation */
     QTAILQ_INIT(&plugin.ctxs);
     qht_init(&plugin.dyn_cb_arr_ht, plugin_dyn_cb_arr_cmp, 16,
              QHT_MODE_AUTO_RESIZE);
@@ -588,3 +627,27 @@ int plugin_num_vcpus(void)
 {
     return plugin.num_vcpus;
 }
+
+struct qemu_plugin_scoreboard *plugin_scoreboard_new(size_t element_size)
+{
+    struct qemu_plugin_scoreboard *score =
+        g_malloc0(sizeof(struct qemu_plugin_scoreboard));
+    score->data = g_array_new(FALSE, TRUE, element_size);
+    g_array_set_size(score->data, plugin.scoreboard_alloc_size);
+
+    qemu_rec_mutex_lock(&plugin.lock);
+    QLIST_INSERT_HEAD(&plugin.scoreboards, score, entry);
+    qemu_rec_mutex_unlock(&plugin.lock);
+
+    return score;
+}
+
+void plugin_scoreboard_free(struct qemu_plugin_scoreboard *score)
+{
+    qemu_rec_mutex_lock(&plugin.lock);
+    QLIST_REMOVE(score, entry);
+    qemu_rec_mutex_unlock(&plugin.lock);
+
+    g_array_free(score->data, TRUE);
+    g_free(score);
+}
diff --git a/plugins/plugin.h b/plugins/plugin.h
index 00b3509f70..7c34f23cfc 100644
--- a/plugins/plugin.h
+++ b/plugins/plugin.h
@@ -31,6 +31,8 @@ struct qemu_plugin_state {
      * but with the HT we avoid adding a field to CPUState.
      */
     GHashTable *cpu_ht;
+    QLIST_HEAD(, qemu_plugin_scoreboard) scoreboards;
+    size_t scoreboard_alloc_size;
     DECLARE_BITMAP(mask, QEMU_PLUGIN_EV_MAX);
     /*
      * @lock protects the struct as well as ctx->uninstalling.
@@ -66,10 +68,11 @@ struct qemu_plugin_ctx {
 
 struct qemu_plugin_ctx *plugin_id_to_ctx_locked(qemu_plugin_id_t id);
 
-void plugin_register_inline_op(GArray **arr,
-                               enum qemu_plugin_mem_rw rw,
-                               enum qemu_plugin_op op, void *ptr,
-                               uint64_t imm);
+void plugin_register_inline_op_on_entry(GArray **arr,
+                                        enum qemu_plugin_mem_rw rw,
+                                        enum qemu_plugin_op op,
+                                        qemu_plugin_u64 entry,
+                                        uint64_t imm);
 
 void plugin_reset_uninstall(qemu_plugin_id_t id,
                             qemu_plugin_simple_cb_t cb,
@@ -97,8 +100,12 @@ void plugin_register_vcpu_mem_cb(GArray **arr,
                                  enum qemu_plugin_mem_rw rw,
                                  void *udata);
 
-void exec_inline_op(struct qemu_plugin_dyn_cb *cb);
+void exec_inline_op(struct qemu_plugin_dyn_cb *cb, int cpu_index);
 
 int plugin_num_vcpus(void);
 
+struct qemu_plugin_scoreboard *plugin_scoreboard_new(size_t element_size);
+
+void plugin_scoreboard_free(struct qemu_plugin_scoreboard *score);
+
 #endif /* PLUGIN_H */
diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols
index 27fe97239b..a9fac056c7 100644
--- a/plugins/qemu-plugins.symbols
+++ b/plugins/qemu-plugins.symbols
@@ -27,20 +27,27 @@
   qemu_plugin_register_vcpu_idle_cb;
   qemu_plugin_register_vcpu_init_cb;
   qemu_plugin_register_vcpu_insn_exec_cb;
-  qemu_plugin_register_vcpu_insn_exec_inline;
+  qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu;
   qemu_plugin_register_vcpu_mem_cb;
-  qemu_plugin_register_vcpu_mem_inline;
+  qemu_plugin_register_vcpu_mem_inline_per_vcpu;
   qemu_plugin_register_vcpu_resume_cb;
   qemu_plugin_register_vcpu_syscall_cb;
   qemu_plugin_register_vcpu_syscall_ret_cb;
   qemu_plugin_register_vcpu_tb_exec_cb;
-  qemu_plugin_register_vcpu_tb_exec_inline;
+  qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu;
   qemu_plugin_register_vcpu_tb_trans_cb;
   qemu_plugin_reset;
+  qemu_plugin_scoreboard_free;
+  qemu_plugin_scoreboard_find;
+  qemu_plugin_scoreboard_new;
   qemu_plugin_start_code;
   qemu_plugin_tb_get_insn;
   qemu_plugin_tb_n_insns;
   qemu_plugin_tb_vaddr;
+  qemu_plugin_u64_add;
+  qemu_plugin_u64_get;
+  qemu_plugin_u64_set;
+  qemu_plugin_u64_sum;
   qemu_plugin_uninstall;
   qemu_plugin_vcpu_for_each;
 };