From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59560) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZqzfF-0007it-Nf for qemu-devel@nongnu.org; Tue, 27 Oct 2015 04:31:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZqzfB-0007kJ-Mk for qemu-devel@nongnu.org; Tue, 27 Oct 2015 04:31:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58427) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZqzfB-0007kC-Hl for qemu-devel@nongnu.org; Tue, 27 Oct 2015 04:31:25 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 466628C1AA for ; Tue, 27 Oct 2015 08:31:24 +0000 (UTC) Date: Tue, 27 Oct 2015 10:31:21 +0200 From: "Michael S. Tsirkin" Message-ID: <20151027084706-mutt-send-email-mst@redhat.com> References: <1445852815-85168-1-git-send-email-imammedo@redhat.com> <20151026120943-mutt-send-email-mst@redhat.com> <20151026142432.4a8ca282@nial.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151026142432.4a8ca282@nial.brq.redhat.com> Subject: Re: [Qemu-devel] [PATCH v2] pc: memhp: enforce minimal 128Mb alignment for pc-dimm List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: pbonzini@redhat.com, qemu-devel@nongnu.org, ehabkost@redhat.com On Mon, Oct 26, 2015 at 02:24:32PM +0100, Igor Mammedov wrote: > Yep it's workaround but it works around QEMU's broken virtio > implementation in a simple way without need for guest side changes. > > Without foreseeable virtio fix it makes memory hotplug unusable and even > more so if there were a virtio fix it won't fix old guests since you've > said that virtio fix would require changes of both QEMU and guest sides. What makes it not foreseeable? Apparently only the fact that we have a work-around in place so no one works on it. I can code it up pretty quickly, but I'm flat out of time for testing as I'm going on vacation soon, and hard freeze is pretty close. GPA space is kind of cheap, but wasting it in chunks of 512M seems way too aggressive. -- MST