[Qemu-devel] [PATCH 09/21] cpu: add helper cpu_exists(), to check if CPU with specified id exists

[Igor Mammedov]

Signed-off-by: Igor Mammedov <address@hidden>
---
v3:
  * use qemu_for_each_cpu() instead of recursion
v2:
  * s/get_firmware_id()/get_arch_id()/ rebase fixup
  * remove check for get_arch_id being NULL, since it's always defined
---
 include/qom/cpu.h |   10 ++++++++++
 qom/cpu.c         |   26 ++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index d4a21f4..7ba65a5 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -233,6 +233,16 @@ void qemu_for_each_cpu(void (*func)(CPUState *cpu, void 
*data), void *data);
  */
 CPUState *qemu_get_cpu(int index);
 
+/**
+ * cpu_exists:
+ * @id - guest exposed CPU ID to lookup
+ *
+ * Search for CPU with specified ID.
+ *
+ * Returns: true - CPU is found, false - CPU isn't found
+ */
+bool cpu_exists(int64_t id);
+
 #ifndef CONFIG_USER_ONLY
 
 typedef void (*CPUInterruptHandler)(CPUState *, int);
diff --git a/qom/cpu.c b/qom/cpu.c
index d44f987..fcc34aa 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -24,6 +24,32 @@
 #include "qemu/notify.h"
 #include "sysemu/sysemu.h"
 
+typedef struct CPU_exists_args {
+    int64_t id;
+    bool found;
+} CPU_exists_args;
+
+static void cpu_exist_cb(CPUState *cpu, void *data)
+{
+    CPUClass *klass = CPU_GET_CLASS(cpu);
+    CPU_exists_args *arg = data;
+
+    if (klass->get_arch_id(cpu) == arg->id) {
+        arg->found = true;
+    }
+}
+
+bool cpu_exists(int64_t id)
+{
+    CPU_exists_args data = {
+        .id = id,
+        .found = false,
+    };
+
+    qemu_for_each_cpu(cpu_exist_cb, &data);
+    return data.found;
+}
+
 /* CPU hot-plug notifiers */
 static NotifierList cpu_added_notifiers =
     NOTIFIER_LIST_INITIALIZER(cpu_add_notifiers);
-- 
1.7.1