From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54737) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNnfF-0007n5-Pz for qemu-devel@nongnu.org; Thu, 14 Jul 2016 16:55:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bNnf9-0008IU-Rr for qemu-devel@nongnu.org; Thu, 14 Jul 2016 16:55:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48377) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNnf9-0008II-N5 for qemu-devel@nongnu.org; Thu, 14 Jul 2016 16:55:15 -0400 Date: Thu, 14 Jul 2016 17:55:11 -0300 From: Eduardo Habkost Message-ID: <20160714205511.GA3727@thinpad.lan.raisama.net> References: <1468515285-173356-1-git-send-email-imammedo@redhat.com> <1468515285-173356-5-git-send-email-imammedo@redhat.com> <20160714175453.GZ3727@thinpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v4 04/16] pc: forbid BSP removal List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bandan Das Cc: Igor Mammedov , qemu-devel@nongnu.org, pkrempa@redhat.com, mst@redhat.com, eduardo.otubo@profitbricks.com On Thu, Jul 14, 2016 at 02:16:39PM -0400, Bandan Das wrote: > Eduardo Habkost writes: > > > On Thu, Jul 14, 2016 at 06:54:33PM +0200, Igor Mammedov wrote: > >> BSP is assumed to always present in QEMU code, so > >> untile that assumptions are gone, deny removal request. > >> In another words QEMU won't support BSP hot-unplug. > >> > >> Signed-off-by: Igor Mammedov > >> --- > >> hw/i386/pc.c | 7 +++++++ > >> 1 file changed, 7 insertions(+) > >> > >> diff --git a/hw/i386/pc.c b/hw/i386/pc.c > >> index 5a67f15..33c5f97 100644 > >> --- a/hw/i386/pc.c > >> +++ b/hw/i386/pc.c > >> @@ -1751,10 +1751,17 @@ out: > >> static void pc_cpu_unplug_request_cb(HotplugHandler *hotplug_dev, > >> DeviceState *dev, Error **errp) > >> { > >> + int idx; > >> HotplugHandlerClass *hhc; > >> Error *local_err = NULL; > >> PCMachineState *pcms = PC_MACHINE(hotplug_dev); > >> > >> + pc_find_cpu_slot(pcms, CPU(dev), &idx); > > > > Looks fragile: if one day we create any TYPE_CPU object that is > > not in possible_cpus array, idx is undefined. I suggest > > initializing idx to -1 above. > > Or just let pc_find_cpu_slot universally set it to -1 since > this series assumes that -1 means index isn't valid. I think it would be more intuitive if pc_find_cpu_slot() didn't touch *idx if no slot is found. But both ways sound good to me. -- Eduardo