From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43987) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dT7ow-0005gU-J3 for qemu-devel@nongnu.org; Thu, 06 Jul 2017 10:31:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dT7os-0002pb-5i for qemu-devel@nongnu.org; Thu, 06 Jul 2017 10:31:54 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49290) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dT7or-0002p7-S8 for qemu-devel@nongnu.org; Thu, 06 Jul 2017 10:31:50 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v66ESXXG147191 for ; Thu, 6 Jul 2017 10:31:48 -0400 Received: from e24smtp02.br.ibm.com (e24smtp02.br.ibm.com [32.104.18.86]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bhm2r8k7h-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 06 Jul 2017 10:31:47 -0400 Received: from localhost by e24smtp02.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 6 Jul 2017 11:31:45 -0300 From: Daniel Henrique Barboza References: <20170621091848.28256-1-david@gibson.dropbear.id.au> <20170705110414.GN2180@umbus.fritz.box> <0e4deabe-58e9-6c15-5910-cda9f8e63f9b@linux.vnet.ibm.com> Date: Thu, 6 Jul 2017 11:31:35 -0300 MIME-Version: 1.0 In-Reply-To: <0e4deabe-58e9-6c15-5910-cda9f8e63f9b@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Message-Id: <89240dbb-56b7-e540-8981-b6af20eb0d8c@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH 0/5] spapr: DRC cleanups (part VI) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: lvivier@redhat.com, qemu-devel@nongnu.org, sursingh@redhat.com, groug@kaod.org, mdroth@linux.vnet.ibm.com, qemu-ppc@nongnu.org, bharata@linux.vnet.ibm.com On 07/05/2017 06:53 PM, Daniel Henrique Barboza wrote: > Worth a try. I'll see if I can make a POC of this DRC reset at incoming > migration time. Just played a little with the idea of manual reset during migration. I've created a POC that resets the CPU DRCs in a pre_load hook. Then I've done the same experiment - device_add on both source and target before the migration, hot unplug the device after migration is completed. The hot unplug worked as expected in both QEMU and guest. To minimize the impact I am resetting only the DRCs of the CPUs that were hotplugged in the target instead of resetting everybody. I'll see if this solution works for LMBs and PCI devices. In case affirmative, and if we are fine with this solution of resetting the DRCs in pre_load (not sure if pre_load is the right place for doing it - suggestions welcome), I can send a patch to be applied on top of this series. Thanks, Daniel