From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45095) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5sR1-0001KP-T8 for qemu-devel@nongnu.org; Thu, 26 May 2016 06:22:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b5sQw-0007ZA-Oj for qemu-devel@nongnu.org; Thu, 26 May 2016 06:22:34 -0400 Sender: Paolo Bonzini References: <1463024905-28401-1-git-send-email-bharata@linux.vnet.ibm.com> <1463024905-28401-5-git-send-email-bharata@linux.vnet.ibm.com> From: Paolo Bonzini Message-ID: <28681987-a43f-4a04-4b8b-2d5c39ef1f4e@redhat.com> Date: Thu, 26 May 2016 12:22:17 +0200 MIME-Version: 1.0 In-Reply-To: <1463024905-28401-5-git-send-email-bharata@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [for-2.7 PATCH v3 04/15] cpu: Add a sync version of cpu_remove() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bharata B Rao , qemu-devel@nongnu.org Cc: mjrosato@linux.vnet.ibm.com, thuth@redhat.com, pkrempa@redhat.com, ehabkost@redhat.com, aik@ozlabs.ru, armbru@redhat.com, agraf@suse.de, borntraeger@de.ibm.com, qemu-ppc@nongnu.org, imammedo@redhat.com, mdroth@linux.vnet.ibm.com, afaerber@suse.de, david@gibson.dropbear.id.au On 12/05/2016 05:48, Bharata B Rao wrote: > 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 > Reviewed-by: David Gibson > --- > cpus.c | 12 ++++++++++++ > include/qom/cpu.h | 8 ++++++++ > 2 files changed, 20 insertions(+) > > diff --git a/cpus.c b/cpus.c > index 3e7eada..0a6ae44 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -1082,6 +1082,8 @@ 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; > } > @@ -1182,6 +1184,8 @@ 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; > } > } > @@ -1347,6 +1351,14 @@ 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 > > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > index 911bc9f..9c544f6 100644 > --- a/include/qom/cpu.h > +++ b/include/qom/cpu.h > @@ -763,6 +763,14 @@ 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. > Acked-by: Paolo Bonzini