From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56187) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xr63L-0005f1-LO for qemu-devel@nongnu.org; Wed, 19 Nov 2014 09:16:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xr63F-0002gR-DI for qemu-devel@nongnu.org; Wed, 19 Nov 2014 09:16:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35671) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xr63F-0002gG-5S for qemu-devel@nongnu.org; Wed, 19 Nov 2014 09:16:09 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sAJEG84s004899 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 19 Nov 2014 09:16:08 -0500 Date: Wed, 19 Nov 2014 14:16:04 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20141119141603.GD2355@work-vm> References: <87y4r7o8dh.fsf@elfo.elfo> <20141119093320.GA26119@redhat.com> <87d28jo5yp.fsf@elfo.elfo> <20141119102136.GC26395@redhat.com> <878uj7o4ec.fsf@elfo.elfo> <20141119132851.GA27435@redhat.com> <87vbmbmhaj.fsf@elfo.elfo> <546CA051.4050803@redhat.com> <87egszmgn4.fsf@elfo.elfo> <546CA4F5.2080202@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <546CA4F5.2080202@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: "Michael S. Tsirkin" , qemu-devel@nongnu.org, quintela@redhat.com * Paolo Bonzini (pbonzini@redhat.com) wrote: > > > On 19/11/2014 15:03, Juan Quintela wrote: > > Paolo Bonzini wrote: > >> On 19/11/2014 14:49, Juan Quintela wrote: > >>>>> Real hardware lets users update firmware and so should virtual hardware. > >>> But you can hibernate your laptop, update the firmware, and reboot? > >>> Where the change can be anyting, like moving from traditional BIOS to > >>> UEFI? > >> > >> Wait wait wait. I totally cannot follow. What would be the equivalent > >> in QEMU? > > > > qemu-2.0 -M pc-2.0 > > > > migrate to disk/s3/s4 > > > > upgrade qemu > > > > qemu-2.2 -M pc-2.0 > > > > try interesting variation of s3/s4/migration to disk. Migration to disk > > should work (we migrate BIOS ROM blocks, enphasis on ROM), s3 perhaps > > (machine needs to be saved to disk), s4 ..... depends how it ends being > > done. > > Ok, got it. S3 + migrate to disk should work. > > S4 probably would work, but I think it would work on a real system too > as long as you update software and not hardware (e.g. changing the > motherboard would change the MAC address of the on-board NIC, for example). > > Consider the similar case on real hardware: > > boot > update microcode RPM > s4 > turn on > > CPU microcode is installed early by the kernel, before looking for a > hibernation image to resume from, so the CPU microcode after resume from > S4 is different from the microcode at the time you suspended to disk. > This probably would work. You mean, unless for example, someone had disabled a CPU feature in the new microcode? Dave > > Paolo -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK