| Date | Wed, 26 Nov 2014 15:31:02 +0100 | From | Cornelia Huck <> | Subject | Re: [PATCH v4 26/42] vhost/net: force len for TX to host endian |
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On Tue, 25 Nov 2014 18:43:14 +0200 "Michael S. Tsirkin" <mst@redhat.com> wrote:
> We use native endian-ness internally but never > expose it to guest. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > 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)
I find these constants a bit confusing: What does __virtio32 mean without the context of a vq or device?
> > -#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)
And here you cast it to a plain u32 again.
I looked at the final code, and you seem either to use the above constants for .len or do a cpu_to_vhost32(). Wouldn't you need to convert the constants as well?
> > enum { > VHOST_NET_FEATURES = VHOST_FEATURES |
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