Re: [Qemu-devel] [PATCH 08/16] cpu: add helper cpu_exists(), to check if CPU with specified id exists

[Michael S. Tsirkin]

On Tue, Apr 16, 2013 at 12:12:48AM +0200, Igor Mammedov wrote:
> ... it should be used only on slow path since it does recursive search
>     on /machine QOM tree for objects of TYPE_CPU
> 
> Signed-off-by: Igor Mammedov <address@hidden>
> Reviewed-by: Paolo Bonzini <address@hidden>

I would prefer qemu_for_each_cpu, that is also useful for ACPI.  And do
we need to scan all QOM?  This will take a while to repeat if there are
many devices.
How about the below? You can add a wrapper that sets
a bit if CPU exists.


commit 4ff1332ff56069574f450bb44819156bd91bd105
Author: Michael S. Tsirkin <address@hidden>
Date:   Sun Apr 21 15:44:47 2013 +0300

    exec: add qemu_for_each_cpu
    
    Will be used by ACPI table generation.
    
    Signed-off-by: Michael S. Tsirkin <address@hidden>

diff --git a/exec.c b/exec.c
index fa1e0c3..2b44cbe 100644
--- a/exec.c
+++ b/exec.c
@@ -265,6 +265,19 @@ CPUState *qemu_get_cpu(int index)
     return env ? cpu : NULL;
 }
 
+void qemu_for_each_cpu( void (*func)( CPUState *c, void *arg), void *arg)
+{
+    CPUArchState *env = first_cpu;
+    CPUState *cpu;
+
+    while (env) {
+        cpu = ENV_GET_CPU(env);
+        func(cpu, arg);
+        env = env->next_cpu;
+    }
+}
+
+
 void cpu_exec_init(CPUArchState *env)
 {
     CPUState *cpu = ENV_GET_CPU(env);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 3664a1b..db857e3 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -223,6 +223,8 @@ void run_on_cpu(CPUState *cpu, void (*func)(void *data), 
void *data);
  */
 CPUState *qemu_get_cpu(int index);
 
+void qemu_for_each_cpu( void (*func)( CPUState *c, void *arg), void *arg);
+
 #ifndef CONFIG_USER_ONLY
 
 typedef void (*CPUInterruptHandler)(CPUState *, int);