From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43450) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXDTy-0007aY-Hg for qemu-devel@nongnu.org; Tue, 30 Apr 2013 12:32:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UXDTv-0000wj-Tw for qemu-devel@nongnu.org; Tue, 30 Apr 2013 12:32:46 -0400 Date: Tue, 30 Apr 2013 19:30:57 +0300 From: "Michael S. Tsirkin" Message-ID: <20130430163057.GA5475@redhat.com> References: <1360111706-13138-1-git-send-email-mdroth@linux.vnet.ibm.com> <87lib2cf6j.fsf@codemonkey.ws> <20130430090800.GA28318@redhat.com> <878v40vvhq.fsf@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878v40vvhq.fsf@codemonkey.ws> Subject: Re: [Qemu-devel] [PATCH for-1.4 0/2] fix migration failure from 1.3 due to SeaBIOS size change List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: quintela@redhat.com, qemu-devel@nongnu.org, Michael Roth , qemu-stable@nongnu.org, owasserm@redhat.com, kraxel@redhat.com On Tue, Apr 30, 2013 at 11:22:41AM -0500, Anthony Liguori wrote: > "Michael S. Tsirkin" writes: > > > On Tue, Feb 05, 2013 at 09:08:20PM -0600, Anthony Liguori wrote: > >> Michael Roth writes: > >> > >> > Migration from 1.3 currently fails due to a mismatch between the expected size > >> > of 256KB and the received size of 128KB for seabios. This series attempts to > >> > fix the issue by allowing a resize function to be registered to handle resizing > >> > memory blocks to accomodate the source's, and using that to re-initialize > >> > "pc.bios" and "isa-bios" MemoryRegions based on the size of the incoming block. > >> > > >> > There are also 2 potential alternatives to this patch set: > >> > > >> > 1) When I compile seabios 1.7.2 locally I end up with a 128KB binary. > >> > >> So do I on Fedora 18. Unless someone has a reason why this is a bad > >> thing, I'll commit a 128kb binary and we can avoid this problem for 1.4. > >> > >> Obviously, we need to figure it out but that at least buys us some time... > >> > >> Regards, > >> > >> Anthony Liguori > > > > So we never bothered with this patch, and so it's still out. > > How about we apply this for 1.5? > > This problem occurred because Gerd built SeaBIOS on RHEL6.x which > resulted in a 256k binary. > > On F18, we're still fitting in 128k. There is no reason to worry about > BIOS size right now. > > At some point, we will need to split into two separate BIOSes--a 128Kb > and a 256Kb. This can be handled by having two SeaBIOS configuration > files where one has a reduced feature set. > > We then would create an i440fx property that selects either the 128Kb or > 256Kb BIOS. This property can then be setup as part of machine globals. > > So -M 1.4 or -M 1.5 will always use a 128Kb BIOS. If we need to, 1.6 > may end up with a 256Kb BIOS. > > > This way we, at least, won't have the problem with -M1.5 in the future. > > Barring that - early in 1.6 cycle? > > The problem with Mike's patch is that it only solves older -> newer. > The solution I outlined above also works for newer -> older. > > Regards, > > Anthony Liguori Why doesn't the same approach work for new->old? I am guessing you are talking about migration to 1.4 and older? > > > > -- > > MST