From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54991) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNcn6-0006Dp-A9 for qemu-devel@nongnu.org; Thu, 14 Jul 2016 05:18:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bNcn2-00071N-KV for qemu-devel@nongnu.org; Thu, 14 Jul 2016 05:18:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36255) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNcn2-00070w-1k for qemu-devel@nongnu.org; Thu, 14 Jul 2016 05:18:40 -0400 Date: Thu, 14 Jul 2016 11:18:36 +0200 From: Igor Mammedov Message-ID: <20160714111836.22bff3f9@nial.brq.redhat.com> In-Reply-To: <20160713233713.GR3727@thinpad.lan.raisama.net> References: <1467786055-85835-1-git-send-email-imammedo@redhat.com> <1467786055-85835-11-git-send-email-imammedo@redhat.com> <20160713224420.GQ3727@thinpad.lan.raisama.net> <20160713233713.GR3727@thinpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 10/19] pc: register created initial and hotpluged CPUs in one place pc_cpu_plug() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Bandan Das , pkrempa@redhat.com, mst@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, eduardo.otubo@profitbricks.com, pbonzini@redhat.com, marcel@redhat.com, rth@twiddle.net On Wed, 13 Jul 2016 20:37:13 -0300 Eduardo Habkost wrote: > On Wed, Jul 13, 2016 at 06:59:21PM -0400, Bandan Das wrote: > > Eduardo Habkost writes: > > > > > On Wed, Jul 13, 2016 at 06:32:27PM -0400, Bandan Das wrote: > > >> Igor Mammedov writes: > > >> > > >> > consolidate possible_cpus array management in pc_cpu_plug() > > >> > for smp_cpus, coldplugged with -device and hotplugged with > > >> > device_add. > > >> > > >> So, this takes care of the hotplug case and 09/19 took care of the > > >> coldplug case, right ? If yes, we should probably modify this commit > > >> message a little. > > > > > > This makes pc_cpu_plug() take care of both: now it will handle > > > the coldplug case also (in addition to the hotplug case, that it > > > already handled). I don't understand what you mean. > > > > > > Are you talking about the rtc_set_memory() call, only? This seems > > > to be the only hotplug-specific code that still remains, in this > > > > Right, I thought the rtc_set_memory() call in 09/19 takes care of the > > case when the user boots with "-device" and this takes care of the case > > when user invokes device_add, no ? > > Yes for rtc_set_memory(). But the main purpose of this patch is > to reuse all the rest of pc_cpu_plug() (i.e. everything except > for the rtc_set_memory() call) for the coldplug CPUs too. > > Note that I didn't review the patch completely, yet. The > replacement for the possible_cpus code looks OK, but I didn't > check if it is safe to call > HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev)->plug() for coldplugged > CPUs too. for cpus created at pc_cpus_init() time, that path is unreachable since pcms->acpi_dev == NULL, even if in the future that path becomes reachable (when we could specify all CPUs including BSP with -device, it doesn't work for BSP yet) i.e. pcms->acpi_dev != NULL then acpi_device will have be initialized see cpu_hotplug_hw_init() and following plug handler will be called acpi_cpu_plug_cb() doing what it was supposed to do. > > > > > > patch. > > > > > >> > > >> Bandan > > >> > Signed-off-by: Igor Mammedov > > >> > --- > > >> > hw/i386/pc.c | 25 +++++++++---------------- > > >> > 1 file changed, 9 insertions(+), 16 deletions(-) > > >> > > > >> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > >> > index 3206572..0f85b56 100644 > > >> > --- a/hw/i386/pc.c > > >> > +++ b/hw/i386/pc.c > > >> > @@ -1142,7 +1142,6 @@ void pc_cpus_init(PCMachineState *pcms) > > >> > if (i < smp_cpus) { > > >> > cpu = pc_new_cpu(typename, x86_cpu_apic_id_from_index(i), > > >> > &error_fatal); > > >> > - pcms->possible_cpus->cpus[i].cpu = CPU(cpu); > > >> > object_unref(OBJECT(cpu)); > > >> > } > > >> > } > > >> > @@ -1697,25 +1696,19 @@ static void pc_cpu_plug(HotplugHandler *hotplug_dev, > > >> > Error *local_err = NULL; > > >> > PCMachineState *pcms = PC_MACHINE(hotplug_dev); > > >> > > > >> > - if (!dev->hotplugged) { > > >> > - goto out; > > >> > - } > > >> > - > > >> > - if (!pcms->acpi_dev) { > > >> > - error_setg(&local_err, > > >> > - "cpu hotplug is not enabled: missing acpi device"); > > >> > - goto out; > > >> > + if (pcms->acpi_dev) { > > >> > + hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev); > > >> > + hhc->plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err); > > >> > + if (local_err) { > > >> > + goto out; > > >> > + } > > >> > } > > >> > > > >> > - hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev); > > >> > - hhc->plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err); > > >> > - if (local_err) { > > >> > - goto out; > > >> > + if (dev->hotplugged) { > > >> > + /* increment the number of CPUs */ > > >> > + rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, 0x5f) + 1); > > >> > } > > >> > > > >> > - /* increment the number of CPUs */ > > >> > - rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, 0x5f) + 1); > > >> > - > > >> > found_cpu = pc_find_cpu_slot(pcms, CPU(dev), NULL); > > >> > found_cpu->cpu = CPU(dev); > > >> > out: >