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 <bhar...@linux.vnet.ibm.com> --- cpus.c | 14 ++++++++++++++ include/qom/cpu.h | 8 ++++++++ 2 files changed, 22 insertions(+) diff --git a/cpus.c b/cpus.c index 73ae2e7..9d9644e 100644 --- a/cpus.c +++ b/cpus.c @@ -999,6 +999,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg) qemu_kvm_wait_io_event(cpu); if (cpu->exit && !cpu_can_run(cpu)) { qemu_kvm_destroy_vcpu(cpu); + cpu->created = false; + qemu_cond_signal(&qemu_cpu_cond); qemu_mutex_unlock(&qemu_global_mutex); return NULL; } @@ -1104,6 +1106,8 @@ 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; } } @@ -1283,6 +1287,16 @@ void cpu_remove(CPUState *cpu) qemu_cpu_kick(cpu); } +void cpu_remove_sync(CPUState *cpu) +{ + cpu->stop = true; + cpu->exit = true; + qemu_cpu_kick(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 diff --git a/include/qom/cpu.h b/include/qom/cpu.h index 136d9fe..65c6852 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -655,6 +655,14 @@ 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. -- 2.1.0