From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: Re: [PATCH v7 30/46] vhost/net: force len for TX to host endian Date: Mon, 1 Dec 2014 13:20:51 +0100 Message-ID: <20141201132051.4ab028d9.cornelia.huck@de.ibm.com> References: <1417359787-10138-1-git-send-email-mst@redhat.com> <1417359787-10138-31-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: thuth@linux.vnet.ibm.com, kvm@vger.kernel.org, rusty@au1.ibm.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, dahi@linux.vnet.ibm.com, pbonzini@redhat.com, David Miller To: "Michael S. Tsirkin" Return-path: In-Reply-To: <1417359787-10138-31-git-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 List-Id: netdev.vger.kernel.org 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." ? > > 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 |