> -----Original Message----- > From: Yuanhan Liu [mailto:yuanhan.liu at linux.intel.com] > Sent: Wednesday, November 11, 2015 4:44 PM > To: Liu, Jijiang > Cc: Michael S. Tsirkin; dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest offload > capabilities > > On Wed, Nov 11, 2015 at 08:38:29AM +0000, Liu, Jijiang wrote: > > > > > > > -----Original Message----- > > > From: Yuanhan Liu [mailto:yuanhan.liu at linux.intel.com] > > > Sent: Wednesday, November 11, 2015 4:31 PM > > > To: Liu, Jijiang; Michael S. Tsirkin > > > Cc: dev at dpdk.org > > > Subject: Re: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest > > > offload capabilities > > > > > > On Wed, Nov 11, 2015 at 02:40:45PM +0800, Jijiang Liu wrote: > > > > Add virtio guest offload capabilities. > > > > > > > > Signed-off-by: Jijiang Liu <jijiang.liu at intel.com> > > > > --- > > > > lib/librte_vhost/virtio-net.c | 5 ++++- > > > > 1 files changed, 4 insertions(+), 1 deletions(-) > > > > > > > > diff --git a/lib/librte_vhost/virtio-net.c > > > > b/lib/librte_vhost/virtio-net.c index 81bd309..839a333 100644 > > > > --- a/lib/librte_vhost/virtio-net.c > > > > +++ b/lib/librte_vhost/virtio-net.c > > > > @@ -80,7 +80,10 @@ static struct virtio_net_config_ll *ll_root; > > > > (1ULL << > > > VHOST_USER_F_PROTOCOL_FEATURES) | \ > > > > (1ULL << VIRTIO_NET_F_HOST_TSO4) | \ > > > > (1ULL << VIRTIO_NET_F_HOST_TSO6) | \ > > > > - (1ULL << VIRTIO_NET_F_CSUM)) > > > > + (1ULL << VIRTIO_NET_F_CSUM) | \ > > > > + (1ULL << VIRTIO_NET_F_GUEST_CSUM) | \ > > > > + (1ULL << VIRTIO_NET_F_GUEST_TSO4) | \ > > > > + (1ULL << VIRTIO_NET_F_GUEST_TSO6)) > > > > > > I don't think we need that, and it might be wrong to set those fields at > vhost. > > > > > > And, TBH, I am not 100% sure that I understand what those flags > > > truely are and for. All I know is that they seem have something to > > > do with QEMU/TAP device. > > > > According to virtio standard, those fileds should be set. > > If so, you'd better quote them here, or even to your patch commit.
In the Virtual I/O Device (VIRTIO) Version 1.0 Committee Specification 02, (1) VIRTIO_NET_F_GUEST_CSUM (1) Driver handles packets with partial checksum. (2) If the VIRTIO_NET_F_GUEST_CSUM feature was negotiated, the VIRTIO_NET_HDR_F_NEEDS_- CSUM bit in flags MAY be set: if so, the checksum on the packet is incomplete and csum_start and csum_offset indicate how to calculate it (see Packet Transmission point 1). (3) If the VIRTIO_NET_F_GUEST_TSO4, TSO6 or UFO options were negotiated, then gso_type MAY be something other than VIRTIO_NET_HDR_GSO_NONE, and gso_size field indicates the desired MSS (see Packet Transmission point 2). The information can be included in the next version of patch set. > --yliu > > > Yes, I'd like to listen other guys comments. > > > > > Hopefully the virtio expert, Michael, could shine some lights on that. > > > > > > --yliu > > > > > > > > > > > static uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES; > > > > > > > > -- > > > > 1.7.7.6
