From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54145) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f5uZB-00034E-8s for qemu-devel@nongnu.org; Tue, 10 Apr 2018 10:48:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f5uZ5-0007vs-Bp for qemu-devel@nongnu.org; Tue, 10 Apr 2018 10:48:13 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:33442 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f5uZ5-0007vU-7d for qemu-devel@nongnu.org; Tue, 10 Apr 2018 10:48:07 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 40BA18E685 for ; Tue, 10 Apr 2018 14:48:03 +0000 (UTC) Date: Tue, 10 Apr 2018 16:47:56 +0200 From: Kevin Wolf Message-ID: <20180410144756.GG7026@localhost.localdomain> References: <20180404100303.GE4482@localhost.localdomain> <20180409102744.GC2449@work-vm> <20180409134003.GG5294@localhost.localdomain> <20180410073635.GA91107@orkuz.home> <20180410081848.GA7026@localhost.localdomain> <20180410084524.GB2559@work-vm> <20180410091437.GC7026@localhost.localdomain> <20180410104047.GD2559@work-vm> <20180410122652.GD7026@localhost.localdomain> <20180410142253.GG2559@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180410142253.GG2559@work-vm> Subject: Re: [Qemu-devel] [PATCH] migration: Don't activate block devices if using -S List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: Jiri Denemark , qemu-devel@nongnu.org, quintela@redhat.com, famz@redhat.com, peterx@redhat.com Am 10.04.2018 um 16:22 hat Dr. David Alan Gilbert geschrieben: > * Kevin Wolf (kwolf@redhat.com) wrote: > > Am 10.04.2018 um 12:40 hat Dr. David Alan Gilbert geschrieben: > > > Hmm; having chatted to Jiri I'm OK with reverting it, on the condition > > > that I actually understand how this alternative would work first. > > > > > > I can't currently see how a block-inactivate would be used. > > > I also can't see how a block-activate unless it's also with the > > > change that you're asking to revert. > > > > > > Can you explain the way you see it working? > > > > The key is making the delayed activation of block devices (and probably > > delayed announcement of NICs? - you didn't answer that part) optional > > instead of making it the default. > > NIC announcments are broken in similar but slightly different ways; we > did have a series on list to help a while ago but it never got merged; > I'd like to keep that mess separate. Okay. I just thought that it would make sense to have clear migration phases that are the same for all external resources that the QEMU processes use. > > We can use Jirka's suggestion of adding a migration capability that > > enables it, or I suppose a new option to -incoming could work, too. It > > doesn't really matter what the syntax is, but the management tool must > > request it explicitly. > > A new capability is easy to gate the change in behaviour that this patch > added; I'll do that first thing for 2.13 (given today is rc3 tag it's > too late). > > However, once we turn this on, to cope with the situation of a block user > that must start prior to the 'cont' when this behaviour is active, we'd > also need the 'block-activate' command. Yes, that's right. Kevin