From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34980) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YkIOw-000180-AS for qemu-devel@nongnu.org; Mon, 20 Apr 2015 16:34:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YkIOr-00031x-PQ for qemu-devel@nongnu.org; Mon, 20 Apr 2015 16:34:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50124) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YkIOr-00031f-Ir for qemu-devel@nongnu.org; Mon, 20 Apr 2015 16:34:37 -0400 Date: Mon, 20 Apr 2015 22:34:28 +0200 From: "Michael S. Tsirkin" Message-ID: <20150420223113-mutt-send-email-mst@redhat.com> References: <1429257573-7359-1-git-send-email-famz@redhat.com> <20150420175905-mutt-send-email-mst@redhat.com> <55354F0A.5080809@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55354F0A.5080809@redhat.com> Subject: Re: [Qemu-devel] [PATCH 00/18] virtio-blk: Support "VIRTIO_CONFIG_S_NEEDS_RESET" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Fam Zheng , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, "Aneesh Kumar K.V" , Stefan Hajnoczi , Amit Shah On Mon, Apr 20, 2015 at 09:10:02PM +0200, Paolo Bonzini wrote: > > > On 20/04/2015 19:36, Michael S. Tsirkin wrote: > > At the implementation level, there's one big issue you seem to have > > missed: DMA to invalid memory addresses causes a crash in memory core. > > I'm not sure whether it makes sense to recover from virtio core bugs > > when we can't recover from device bugs. > > What do you mean exactly? DMA to invalid memory addresses causes > address_space_map to return a "short read". > > Paolo I mean, first of all, a bunch of virtio_XXX_phys calls. These eventually call qemu_get_ram_ptr, which internally calls qemu_get_ram_block and ramblock_ptr. Both abort on errors. -- MST