| Message ID | 20230522073950.3574171-5-AVKrasnov@sberdevices.ru (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vsock: MSG_ZEROCOPY flag support | expand |
On Mon, May 22, 2023 at 10:39:37AM +0300, Arseniy Krasnov wrote: > For tap device new skb is created and data from the current skb is > copied to it. This adds copying data from non-linear skb to new > the skb. > > Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> > --- > net/vmw_vsock/virtio_transport_common.c | 31 ++++++++++++++++++++++--- > 1 file changed, 28 insertions(+), 3 deletions(-) > > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c > index 16effa8d55d2..9854f48a0544 100644 > --- a/net/vmw_vsock/virtio_transport_common.c > +++ b/net/vmw_vsock/virtio_transport_common.c > @@ -106,6 +106,27 @@ virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info, > return NULL; > } > > +static void virtio_transport_copy_nonlinear_skb(struct sk_buff *skb, > + void *dst, > + size_t len) > +{ > + struct iov_iter iov_iter = { 0 }; > + struct iovec iovec; > + size_t to_copy; > + > + iovec.iov_base = dst; Hi Arseniy, Sparse seems unhappy about this. Though, TBH, I'm unsure what should be done about it. .../virtio_transport_common.c:117:24: warning: incorrect type in assignment (different address spaces) .../virtio_transport_common.c:117:24: expected void [noderef] __user *iov_base .../virtio_transport_common.c:117:24: got void *dst ...
On 22.05.2023 16:13, Simon Horman wrote: > On Mon, May 22, 2023 at 10:39:37AM +0300, Arseniy Krasnov wrote: >> For tap device new skb is created and data from the current skb is >> copied to it. This adds copying data from non-linear skb to new >> the skb. >> >> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> >> --- >> net/vmw_vsock/virtio_transport_common.c | 31 ++++++++++++++++++++++--- >> 1 file changed, 28 insertions(+), 3 deletions(-) >> >> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c >> index 16effa8d55d2..9854f48a0544 100644 >> --- a/net/vmw_vsock/virtio_transport_common.c >> +++ b/net/vmw_vsock/virtio_transport_common.c >> @@ -106,6 +106,27 @@ virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info, >> return NULL; >> } >> >> +static void virtio_transport_copy_nonlinear_skb(struct sk_buff *skb, >> + void *dst, >> + size_t len) >> +{ >> + struct iov_iter iov_iter = { 0 }; >> + struct iovec iovec; >> + size_t to_copy; >> + >> + iovec.iov_base = dst; > > Hi Arseniy, > > Sparse seems unhappy about this. > Though, TBH, I'm unsure what should be done about it. > > .../virtio_transport_common.c:117:24: warning: incorrect type in assignment (different address spaces) > .../virtio_transport_common.c:117:24: expected void [noderef] __user *iov_base > .../virtio_transport_common.c:117:24: got void *dst > Got it, i'll check how to resolve this problem! Thanks! > > ...
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 16effa8d55d2..9854f48a0544 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -106,6 +106,27 @@ virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info, return NULL; } +static void virtio_transport_copy_nonlinear_skb(struct sk_buff *skb, + void *dst, + size_t len) +{ + struct iov_iter iov_iter = { 0 }; + struct iovec iovec; + size_t to_copy; + + iovec.iov_base = dst; + iovec.iov_len = len; + + iov_iter.iter_type = ITER_IOVEC; + iov_iter.__iov = &iovec; + iov_iter.nr_segs = 1; + + to_copy = min_t(size_t, len, skb->len); + + skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->frag_off, + &iov_iter, to_copy); +} + /* Packet capture */ static struct sk_buff *virtio_transport_build_skb(void *opaque) { @@ -114,7 +135,6 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) struct af_vsockmon_hdr *hdr; struct sk_buff *skb; size_t payload_len; - void *payload_buf; /* A packet could be split to fit the RX buffer, so we can retrieve * the payload length from the header and the buffer pointer taking @@ -122,7 +142,6 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) */ pkt_hdr = virtio_vsock_hdr(pkt); payload_len = pkt->len; - payload_buf = pkt->data; skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len, GFP_ATOMIC); @@ -165,7 +184,13 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr)); if (payload_len) { - skb_put_data(skb, payload_buf, payload_len); + if (skb_is_nonlinear(pkt)) { + void *data = skb_put(skb, payload_len); + + virtio_transport_copy_nonlinear_skb(pkt, data, payload_len); + } else { + skb_put_data(skb, pkt->data, payload_len); + } } return skb;
For tap device new skb is created and data from the current skb is copied to it. This adds copying data from non-linear skb to new the skb. Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> --- net/vmw_vsock/virtio_transport_common.c | 31 ++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-)