Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753436AbaLAMdy (ORCPT ); Mon, 1 Dec 2014 07:33:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752759AbaLAMdw (ORCPT ); Mon, 1 Dec 2014 07:33:52 -0500 Date: Mon, 1 Dec 2014 14:33:34 +0200 From: "Michael S. Tsirkin" To: Cornelia Huck Cc: linux-kernel@vger.kernel.org, David Miller , rusty@au1.ibm.com, nab@linux-iscsi.org, pbonzini@redhat.com, thuth@linux.vnet.ibm.com, dahi@linux.vnet.ibm.com, Jason Wang , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: Re: [PATCH v7 30/46] vhost/net: force len for TX to host endian Message-ID: <20141201123334.GB17875@redhat.com> References: <1417359787-10138-1-git-send-email-mst@redhat.com> <1417359787-10138-31-git-send-email-mst@redhat.com> <20141201132051.4ab028d9.cornelia.huck@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141201132051.4ab028d9.cornelia.huck@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 01, 2014 at 01:20:51PM +0100, Cornelia Huck wrote: > On Sun, 30 Nov 2014 17:11:44 +0200 > "Michael S. Tsirkin" wrote: > > > vhost/net keeps a copy of some used ring but (ab)uses length > > field for internal house-keeping. This works because > > for tx used length is always 0. > > Suppress sparse errors: we use native endian-ness internally but never > > expose it to guest. > > I admit that I find this patch description hard to read :) > > > "vhost/net keeps a copy of the used ring in host memory but (ab)uses > the length field for internal house-keeping. This works because the > length in the used ring for tx is always 0. In order to suppress sparse > errors, we need to force native endianness." > > ? Yes. Add to this "These values are never exposed to guest." > > > > Signed-off-by: Michael S. Tsirkin > > Reviewed-by: Jason Wang > > --- > > drivers/vhost/net.c | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > > index 8dae2f7..dce5c58 100644 > > --- a/drivers/vhost/net.c > > +++ b/drivers/vhost/net.c > > @@ -48,15 +48,15 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" > > * status internally; used for zerocopy tx only. > > */ > > /* Lower device DMA failed */ > > -#define VHOST_DMA_FAILED_LEN 3 > > +#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3) > > /* Lower device DMA done */ > > -#define VHOST_DMA_DONE_LEN 2 > > +#define VHOST_DMA_DONE_LEN ((__force __virtio32)2) > > /* Lower device DMA in progress */ > > -#define VHOST_DMA_IN_PROGRESS 1 > > +#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1) > > /* Buffer unused */ > > -#define VHOST_DMA_CLEAR_LEN 0 > > +#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0) > > > > -#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN) > > +#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN) > > > > enum { > > VHOST_NET_FEATURES = VHOST_FEATURES | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/