From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52079) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dfjg2-0005B5-JG for qemu-devel@nongnu.org; Thu, 10 Aug 2017 05:22:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dfjfy-00051M-9k for qemu-devel@nongnu.org; Thu, 10 Aug 2017 05:22:50 -0400 Received: from mail-lf0-x242.google.com ([2a00:1450:4010:c07::242]:36377) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dfjfy-00050N-20 for qemu-devel@nongnu.org; Thu, 10 Aug 2017 05:22:46 -0400 Received: by mail-lf0-x242.google.com with SMTP id t128so126259lff.3 for ; Thu, 10 Aug 2017 02:22:44 -0700 (PDT) Date: Thu, 10 Aug 2017 11:22:41 +0200 From: "Edgar E. Iglesias" Message-ID: <20170810092241.GK4859@toto> References: <1501575048-13485-1-git-send-email-frederic.konrad@adacore.com> <1501575048-13485-3-git-send-email-frederic.konrad@adacore.com> <086e70d6-d5c1-2879-874f-ea1804c6ab38@adacore.com> <20170801093015.GA4859@toto> <48d4b55f-6463-48a8-8ed3-b72110005377@adacore.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH for-2.10 2/2] xilinx-spips: add a migration blocker when using mmio_execution List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: KONRAD Frederic , QEMU Developers , Alistair Francis , "Dr. David Alan Gilbert" , Juan Quintela On Thu, Aug 10, 2017 at 10:11:13AM +0100, Peter Maydell wrote: > On 1 August 2017 at 10:41, Peter Maydell wrote: > > On 1 August 2017 at 10:35, KONRAD Frederic wrote: > >> > >> > >> On 08/01/2017 11:30 AM, Edgar E. Iglesias wrote: > >>> At this stage, perhaps we should just register the blocker when this dev > >>> realizes. > >>> > >>> If a request_ptr comes in during migration, the VM will fail either way... > > > >> Yes but this will breaks migration for the spips device everytime > >> and not only when mmio-execution is used? > > > > This line of thought is why I ended up suggesting just disabling > > the exec-in-place feature -- that way we just don't introduce > > what would be a new-in-2.10 feature, rather than breaking something > > that used to work in 2.9. > > OK, so what's the plan here? We have several options: > * just disable exec-from-spips for 2.10 (I sent a patch for that) > * disable exec-from-spips for 2.10 but with a device x-property > to allow the user to turn it on again if they really want it > * this patch or variants on it which try to only disable > migration if exec-from-spips is actually used by the guest > (I don't like these because of the awkward corner cases if > migration and the guest using exec-from-spips happen at the > same time) > > So my current view remains "we should just disable this feature > for 2.10 and we can implement it properly with handling of > migration for 2.11", unless somebody cares enough to implement > the x-property thing within the next day or so. Hi Peter, I think the x-property sounds good. Fred, would you like to send a patch for that? Otherwise, I can do it later today. Cheers, Edgar