From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35664) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ymj12-0000dv-8T for qemu-devel@nongnu.org; Mon, 27 Apr 2015 09:24:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ymj0v-0004XW-SA for qemu-devel@nongnu.org; Mon, 27 Apr 2015 09:24:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42991) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ymj0v-0004X6-KZ for qemu-devel@nongnu.org; Mon, 27 Apr 2015 09:23:57 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t3RDNvQq007314 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 27 Apr 2015 09:23:57 -0400 Date: Mon, 27 Apr 2015 15:23:54 +0200 From: "Michael S. Tsirkin" Message-ID: <20150427152255-mutt-send-email-mst@redhat.com> References: <1430137765-13771-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1430137765-13771-1-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH] virtio-scsi: fix "written length" field in the used ring List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org On Mon, Apr 27, 2015 at 02:29:25PM +0200, Paolo Bonzini wrote: > qsgl->size is the size of the data field after the request or > response header (virtio-scsi currently supports only one such > field; bidirectional requests are not supported). However, > the used ring's len field is not concerned about the field > after the request header, so do not count it unless req->mode > signals the request was a read. > > Also, do not report that anything was written if the request > failed, and subtract any residual bytes in case of buffer underrun. > > Signed-off-by: Paolo Bonzini Acked-by: Michael S. Tsirkin Pls merge through the storage tree. Also, can you pls fix up blk similarly? > --- > hw/scsi/virtio-scsi.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c > index c9bea06..4995f6e 100644 > --- a/hw/scsi/virtio-scsi.c > +++ b/hw/scsi/virtio-scsi.c > @@ -65,6 +65,19 @@ void virtio_scsi_free_req(VirtIOSCSIReq *req) > g_slice_free1(sizeof(*req) + vs->cdb_size, req); > } > > +static size_t virtio_scsi_written_length(VirtIODevice *vdev, VirtIOSCSIReq *req) > +{ > + size_t sz = req->resp_iov.size; > + > + if (req->sreq && > + req->mode == SCSI_XFER_FROM_DEV && > + req->resp.cmd.response == VIRTIO_SCSI_S_OK) { > + sz += req->qsgl.size - virtio_tswap32(vdev, req->resp.cmd.resid); > + } > + > + return sz; > +} > + > static void virtio_scsi_complete_req(VirtIOSCSIReq *req) > { > VirtIOSCSI *s = req->dev; > @@ -76,7 +89,7 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req) > assert(req->vq == NULL); > virtio_scsi_vring_push_notify(req); > } else { > - virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size); > + virtqueue_push(vq, &req->elem, virtio_scsi_written_length(vdev, req)); > virtio_notify(vdev, vq); > } > > -- > 2.3.5