From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Date: Mon, 16 Apr 2018 17:12:03 +0000 Subject: Re: [PATCH net-next 4/5] tun: Add support for SCTP checksum offload Message-Id: <20180416201004-mutt-send-email-mst@kernel.org> List-Id: References: <20180402134006.10111-1-vyasevic@redhat.com> <20180402134006.10111-5-vyasevic@redhat.com> In-Reply-To: <20180402134006.10111-5-vyasevic@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vladislav Yasevich Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org, virtualization@lists.linux-foundation.org, jasowang@redhat.com, nhorman@tuxdriver.com, Vladislav Yasevich On Mon, Apr 02, 2018 at 09:40:05AM -0400, Vladislav Yasevich wrote: > Adds a new tun offload flag to allow for SCTP checksum offload. > The flag has to be set by the user and defaults to "no offload". > > Signed-off-by: Vladislav Yasevich When would user set this flag? Wouldn't that be when userspace is ready to get SCTP packets without a checksum? Seems to be this is an indication that when userspace is qemu running a guest, said guest needs to communicate the new ability to qemu. > --- > drivers/net/tun.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index a1ba262..263bcbe 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -2719,6 +2719,11 @@ static int set_offload(struct tun_struct *tun, unsigned long arg) > arg &= ~TUN_F_UFO; > } > > + if (arg & TUN_F_SCTP_CSUM) { > + features |= NETIF_F_SCTP_CRC; > + arg &= ~TUN_F_SCTP_CSUM; > + } > + > /* This gives the user a way to test for new features in future by > * trying to set them. */ > if (arg) > -- > 2.9.5