From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40435) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YkO6R-0006p7-Gh for qemu-devel@nongnu.org; Mon, 20 Apr 2015 22:40:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YkO6N-0004Sk-Gw for qemu-devel@nongnu.org; Mon, 20 Apr 2015 22:39:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41212) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YkO6N-0004Sg-9O for qemu-devel@nongnu.org; Mon, 20 Apr 2015 22:39:55 -0400 Date: Tue, 21 Apr 2015 10:39:49 +0800 From: Fam Zheng Message-ID: <20150421023949.GD8048@fam-t430.nay.redhat.com> References: <1429257573-7359-1-git-send-email-famz@redhat.com> <20150420175905-mutt-send-email-mst@redhat.com> <55354F0A.5080809@redhat.com> <20150420223113-mutt-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150420223113-mutt-send-email-mst@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: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, "Aneesh Kumar K.V" , Stefan Hajnoczi , Amit Shah , Paolo Bonzini On Mon, 04/20 22:34, Michael S. Tsirkin wrote: > 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. > They are VQ manipulating operations, not DMA. Anyway, can we return errors from memory core? Fam From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fam Zheng Subject: Re: [PATCH 00/18] virtio-blk: Support "VIRTIO_CONFIG_S_NEEDS_RESET" Date: Tue, 21 Apr 2015 10:39:49 +0800 Message-ID: <20150421023949.GD8048@fam-t430.nay.redhat.com> References: <1429257573-7359-1-git-send-email-famz@redhat.com> <20150420175905-mutt-send-email-mst@redhat.com> <55354F0A.5080809@redhat.com> <20150420223113-mutt-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20150420223113-mutt-send-email-mst@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, "Aneesh Kumar K.V" , Stefan Hajnoczi , Amit Shah , Paolo Bonzini List-Id: virtualization@lists.linuxfoundation.org On Mon, 04/20 22:34, Michael S. Tsirkin wrote: > 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. > They are VQ manipulating operations, not DMA. Anyway, can we return errors from memory core? Fam