Commit 2c579042 authored by Bharata B Rao's avatar Bharata B Rao Committed by David Gibson
Browse files

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: default avatarBharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 4c055ab5

cpus.c

+12 −0
Original line number Diff line number Diff line
@@ -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

include/qom/cpu.h

+8 −0
Original line number Diff line number Diff line
@@ -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.