From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51463) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f6b2I-0005tc-MW for qemu-devel@nongnu.org; Thu, 12 Apr 2018 08:09:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f6b2H-0005iZ-PZ for qemu-devel@nongnu.org; Thu, 12 Apr 2018 08:09:06 -0400 Received: from mail-oi0-x236.google.com ([2607:f8b0:4003:c06::236]:40053) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1f6b2H-0005iP-Ko for qemu-devel@nongnu.org; Thu, 12 Apr 2018 08:09:05 -0400 Received: by mail-oi0-x236.google.com with SMTP id x9-v6so4882198oig.7 for ; Thu, 12 Apr 2018 05:09:05 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20180412115326.GF2704@work-vm> References: <20180412101858.21304-1-clg@kaod.org> <20180412115326.GF2704@work-vm> From: Peter Maydell Date: Thu, 12 Apr 2018 13:08:44 +0100 Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] migration: discard RAMBlocks of type ram_device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: =?UTF-8?Q?C=C3=A9dric_Le_Goater?= , QEMU Developers , Juan Quintela , David Gibson , Alex Williamson , Yulei Zhang , "Tian, Kevin" , joonas.lahtinen@linux.intel.com, zhenyuw@linux.intel.com, Kirti Wankhede , zhi.a.wang@intel.com, Eric Blake On 12 April 2018 at 12:53, Dr. David Alan Gilbert wro= te: > * Peter Maydell (peter.maydell@linaro.org) wrote: >> David suggested on IRC that we would want a flag on the ramblock >> for "not migratable", because there are other uses for "don't >> migrate this" than just "is this a ram device". > > My original suggestion to your series was with a flag, but I'd forgotten > about that by the time I'd made the suggestion to C=C3=A9dric. > In your case would just adding an extra term to the > ram_block_is_migratable function work, or do you really need a flag? I don't see how else you would identify the ram block that needs to be skipped. Also I think it's just better design to decouple the decision about "should we migrate this ram block" from the migration code itself, and push it up to the code layer that knows it's creating ram blocks that shouldn't be migrated. thanks -- PMM