From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ej57T-0003Yd-0f for qemu-devel@nongnu.org; Tue, 06 Feb 2018 10:25:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ej57M-0004XQ-S0 for qemu-devel@nongnu.org; Tue, 06 Feb 2018 10:25:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:25387) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ej57M-0004W0-LI for qemu-devel@nongnu.org; Tue, 06 Feb 2018 10:25:08 -0500 Date: Tue, 6 Feb 2018 16:24:33 +0100 From: Igor Mammedov Message-ID: <20180206162433.09922904@redhat.com> In-Reply-To: <20180205183630.GD2317@work-vm> References: <1517842735-9011-1-git-send-email-jianfeng.tan@intel.com> <20180205172918.62588fd6@redhat.com> <20180205183630.GD2317@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC] exec: eliminate ram naming issue as migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: "Tan, Jianfeng" , Paolo Bonzini , Jason Wang , Maxime Coquelin , qemu-devel@nongnu.org, "Michael S . Tsirkin" On Mon, 5 Feb 2018 18:36:31 +0000 "Dr. David Alan Gilbert" wrote: > * Tan, Jianfeng (jianfeng.tan@intel.com) wrote: > > > > > > On 2/6/2018 12:29 AM, Igor Mammedov wrote: > > > On Mon, 5 Feb 2018 14:58:55 +0000 > > > Jianfeng Tan wrote: > > > > > > > Existing VMs with virtio devices and vhost-kernel as the backend > > > > are always started with mem config: > > > > > > > > "-m xG" > > > > (with a ram block named "pc.ram") > > > > > > > > while new VMs with virtio devices and vhost-user as the backend > > > > are always started with mem config: > > > > > > > > "-m xG -numa node,memdev=pc.ram -object memory-backend-file,id=pc.ram,..." > > > > (with a ram block named "/object/pc.ram") > > > could you elaborate more on what src command line migrating to what dst command line? > > > > The src cmdline: > > $QEMU -enable-kvm -cpu host -smp 4 /path/to/img \ > > -m 2G \ > > -netdev tap,id=mynet1,vhost=on \ > > -device virtio-net-pci,netdev=mynet1,mac=52:54:00:12:34:58 ... > > > > The dst cmdline: > > $QEMU -enable-kvm -cpu host -smp 4 /path/to/img \ > > -m 2G -numa node,memdev=pc.ram -mem-prealloc \ > > -object > > memory-backend-file,id=pc.ram,size=2G,mem-path=/dev/hugepages,share=on \ > > -chardev socket,id=char0,path=/tmp/sock0 \ > > -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \ > > -device virtio-net-pci,netdev=mynet1,mac=52:54:00:12:34:58 \ > > -incoming tcp:0:4444 ... > > I'm surprised that it's safe to -numa node the destination, even with > the hack to the RAMBlock naming. I'd expect it to have other effects > as well. it supposed to be 2 mutually exclusive configurations, but migration stream doesn't have that information explicitly (different id naming/mapping could fail migration). > Dave > > > Thanks, > > Jianfeng > > > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK