[PATCH v4 28/40] bsd-user: Add cpu_copy and make init_task_state non-static

Add cpu_copy() function for thread creation support and make
init_task_state() non-static so it can be called from os-thread.c.
Move cpu_type to file scope so cpu_copy() can access it.

Signed-off-by: Stacey Son <[email protected]>
Assisted-by: Claude Opus 4.6 (1M context)
Reviewed-by: Pierrick Bouvier <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Acked-by: Richard Henderson <[email protected]>
Signed-off-by: Warner Losh <[email protected]>
---
 bsd-user/main.c | 32 ++++++++++++++++++++++++++++++--
 bsd-user/qemu.h |  1 +
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/bsd-user/main.c b/bsd-user/main.c
index 694481ae3e..2fbbfc3d86 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -50,6 +50,7 @@
 #include "qemu/guest-random.h"
 #include "gdbstub/user.h"
 #include "exec/page-vary.h"
+#include "exec/watchpoint.h"
 
 #include "host-os.h"
 #include "target_arch_cpu.h"
@@ -215,7 +216,7 @@ bool qemu_cpu_is_self(CPUState *cpu)
 }
 
 /* Assumes contents are already zeroed.  */
-static void init_task_state(TaskState *ts)
+void init_task_state(TaskState *ts)
 {
     ts->sigaltstack_used = (struct target_sigaltstack) {
         .ss_sp = 0,
@@ -224,6 +225,34 @@ static void init_task_state(TaskState *ts)
     };
 }
 
+static const char *cpu_type;
+
+CPUArchState *cpu_copy(CPUArchState *env)
+{
+    CPUState *cpu = env_cpu(env);
+    CPUState *new_cpu = cpu_create(cpu_type);
+    CPUArchState *new_env = cpu_env(new_cpu);
+    CPUBreakpoint *bp;
+
+    /* Reset non arch specific state */
+    cpu_reset(new_cpu);
+
+    new_cpu->tcg_cflags = cpu->tcg_cflags;
+    memcpy(new_env, env, sizeof(CPUArchState));
+
+    /*
+     * Clone all break/watchpoints.
+     * Note: Once we support ptrace with hw-debug register access, make sure
+     * BP_CPU break/watchpoints are handled correctly on clone.
+     */
+    QTAILQ_INIT(&new_cpu->breakpoints);
+    QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
+        cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
+    }
+
+    return new_env;
+}
+
 static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
 
 void gemu_log(const char *fmt, ...)
@@ -256,7 +285,6 @@ int main(int argc, char **argv)
 {
     const char *filename;
     const char *cpu_model;
-    const char *cpu_type;
     const char *log_file = NULL;
     const char *log_mask = NULL;
     const char *seed_optarg = NULL;
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index 069baa7011..d2dd8c2ee8 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -122,6 +122,7 @@ struct TaskState {
     struct target_sigaltstack sigaltstack_used;
 } __attribute__((aligned(16)));
 
+void init_task_state(TaskState *ts);
 void stop_all_tasks(void);
 extern const char *interp_prefix;
 extern const char *qemu_uname_release;

-- 
2.55.0