[Qemu-devel] [PATCH v2] cpu: Correct cpu-hotplug failure

[Chen Fan]

v1-v2: Change cpu_apic_realize to post_vcpu_init.

When useing x86_64-softmmu --enable-kvm boot qemu, cpu-add command fails to add 
a vcpu,
there show (KVM: setting VAPIC address failed).

The reason is that we use an uninitialized cpu->kvm-fd to ioctl.
so we move realizing apic to the back of qemu_init_vcpu.

Signed-off-by: Chen Fan <address@hidden>
---
 include/qom/cpu.h |  2 ++
 qom/cpu.c         | 13 +++++++++++++
 target-i386/cpu.c | 10 ++++------
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index daf1835..4b16385 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -80,6 +80,7 @@ struct TranslationBlock;
  * @synchronize_from_tb: Callback for synchronizing state from a TCG
  * #TranslationBlock.
  * @get_phys_page_debug: Callback for obtaining a physical address.
+ * @post_vcpu_init: Callback for doing some extra initialization.
  * @vmsd: State description for migration.
  *
  * Represents a CPU family or model.
@@ -108,6 +109,7 @@ typedef struct CPUClass {
     void (*set_pc)(CPUState *cpu, vaddr value);
     void (*synchronize_from_tb)(CPUState *cpu, struct TranslationBlock *tb);
     hwaddr (*get_phys_page_debug)(CPUState *cpu, vaddr addr);
+    void (*post_vcpu_init)(CPUState *cpu, Error **errp);
 
     const struct VMStateDescription *vmsd;
     int (*write_elf64_note)(WriteCoreDumpFunction f, CPUState *cpu,
diff --git a/qom/cpu.c b/qom/cpu.c
index 5c45ab5..28f63b7 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -213,12 +213,25 @@ static ObjectClass *cpu_common_class_by_name(const char 
*cpu_model)
     return NULL;
 }
 
+static void post_vcpu_init(CPUState *cpu, Error **errp)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+    if (cc->post_vcpu_init != NULL) {
+        (*cc->post_vcpu_init)(cpu, errp);
+    }
+}
+
 static void cpu_common_realizefn(DeviceState *dev, Error **errp)
 {
     CPUState *cpu = CPU(dev);
 
     qemu_init_vcpu(cpu);
 
+    post_vcpu_init(cpu, errp);
+    if (error_is_set(errp)) {
+        return;
+    }
+
     if (dev->hotplugged) {
         cpu_synchronize_post_init(cpu);
         notifier_list_notify(&cpu_added_notifiers, dev);
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index cd350cb..d51ab8b 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2311,8 +2311,9 @@ static void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
     apic->cpu = cpu;
 }
 
-static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
+static void x86_cpu_apic_realize(CPUState *s, Error **errp)
 {
+    X86CPU *cpu = X86_CPU(s);
     CPUX86State *env = &cpu->env;
 
     if (env->apic_state == NULL) {
@@ -2326,7 +2327,7 @@ static void x86_cpu_apic_realize(X86CPU *cpu, Error 
**errp)
     }
 }
 #else
-static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
+static void x86_cpu_apic_realize(CPUState *s, Error **errp)
 {
 }
 #endif
@@ -2388,10 +2389,6 @@ static void x86_cpu_realizefn(DeviceState *dev, Error 
**errp)
 
     mce_init(cpu);
 
-    x86_cpu_apic_realize(cpu, &local_err);
-    if (local_err != NULL) {
-        goto out;
-    }
     cpu_reset(CPU(cpu));
 
     xcc->parent_realize(dev, &local_err);
@@ -2540,6 +2537,7 @@ static void x86_cpu_common_class_init(ObjectClass *oc, 
void *data)
     cc->synchronize_from_tb = x86_cpu_synchronize_from_tb;
     cc->get_arch_id = x86_cpu_get_arch_id;
     cc->get_paging_enabled = x86_cpu_get_paging_enabled;
+    cc->post_vcpu_init = x86_cpu_apic_realize;
 #ifndef CONFIG_USER_ONLY
     cc->get_memory_mapping = x86_cpu_get_memory_mapping;
     cc->get_phys_page_debug = x86_cpu_get_phys_page_debug;
-- 
1.8.1.4