cpu: Add a sync version of cpu_remove()

This sync API will be used by the CPU hotplug code to wait for the CPU to
completely get removed before flagging the failure to the device_add
command.

Sync version of this call is needed to correctly recover from CPU
realization failures when ->plug() handler fails.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Bharata B Rao 2016-05-12 09:18:14 +05:30 committed by David Gibson
parent 4c055ab54f
commit 2c579042e3
2 changed files with 20 additions and 0 deletions

12
cpus.c
View File

@ -1084,6 +1084,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
} while (!cpu->unplug || cpu_can_run(cpu));
qemu_kvm_destroy_vcpu(cpu);
cpu->created = false;
qemu_cond_signal(&qemu_cpu_cond);
qemu_mutex_unlock_iothread();
return NULL;
}
@ -1184,6 +1186,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
}
if (remove_cpu) {
qemu_tcg_destroy_vcpu(remove_cpu);
cpu->created = false;
qemu_cond_signal(&qemu_cpu_cond);
remove_cpu = NULL;
}
}
@ -1349,6 +1353,14 @@ void cpu_remove(CPUState *cpu)
qemu_cpu_kick(cpu);
}
void cpu_remove_sync(CPUState *cpu)
{
cpu_remove(cpu);
while (cpu->created) {
qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
}
}
/* For temporary buffers for forming a name */
#define VCPU_THREAD_NAME_SIZE 16

View File

@ -772,6 +772,14 @@ void cpu_resume(CPUState *cpu);
*/
void cpu_remove(CPUState *cpu);
/**
* cpu_remove_sync:
* @cpu: The CPU to remove.
*
* Requests the CPU to be removed and waits till it is removed.
*/
void cpu_remove_sync(CPUState *cpu);
/**
* qemu_init_vcpu:
* @cpu: The vCPU to initialize.