| Message ID | ebee740a-95df-ed52-6274-a9340e8dc9d2@sberdevices.ru (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
| Series | vsock: MSG_ZEROCOPY flag support | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessed tree name to be net-next, async |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Series has a cover letter |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/cc_maintainers | success | CCed 9 of 9 maintainers |
| netdev/build_clang | success | Errors and warnings before: 0 this patch: 0 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | No Fixes tag |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/checkpatch | warning | WARNING: line length of 84 exceeds 80 columns |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
On Mon, Feb 06, 2023 at 06:59:21AM +0000, 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 | 43 +++++++++++++++++++++++-- > 1 file changed, 40 insertions(+), 3 deletions(-) > >diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c >index a1581c77cf84..05ce97b967ad 100644 >--- a/net/vmw_vsock/virtio_transport_common.c >+++ b/net/vmw_vsock/virtio_transport_common.c >@@ -101,6 +101,39 @@ 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) >+{ >+ size_t rest_len = len; >+ >+ while (rest_len && virtio_vsock_skb_has_frags(skb)) { >+ struct bio_vec *curr_vec; >+ size_t curr_vec_end; >+ size_t to_copy; >+ int curr_frag; >+ int curr_offs; >+ >+ curr_frag = VIRTIO_VSOCK_SKB_CB(skb)->curr_frag; >+ curr_offs = VIRTIO_VSOCK_SKB_CB(skb)->frag_off; >+ curr_vec = &skb_shinfo(skb)->frags[curr_frag]; >+ >+ curr_vec_end = curr_vec->bv_offset + curr_vec->bv_len; >+ to_copy = min(rest_len, (size_t)(curr_vec_end - curr_offs)); >+ >+ memcpy(dst, page_to_virt(curr_vec->bv_page) + curr_offs, >+ to_copy); >+ >+ rest_len -= to_copy; >+ VIRTIO_VSOCK_SKB_CB(skb)->frag_off += to_copy; >+ >+ if (VIRTIO_VSOCK_SKB_CB(skb)->frag_off == (curr_vec_end)) { >+ VIRTIO_VSOCK_SKB_CB(skb)->curr_frag++; >+ VIRTIO_VSOCK_SKB_CB(skb)->frag_off = 0; >+ } >+ } >+} >+ > /* Packet capture */ > static struct sk_buff *virtio_transport_build_skb(void *opaque) > { >@@ -109,7 +142,6 @@ 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 >@@ -117,7 +149,6 @@ 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); >@@ -160,7 +191,13 @@ 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(skb)) { >+ void *data = skb_put(skb, payload_len); >+ >+ virtio_transport_copy_nonlinear_skb(skb, data, payload_len); >+ } else { >+ skb_put_data(skb, pkt->data, payload_len); >+ } Ehm I'm a bit confused. Maybe we need to rename the sk_buffs involved in this function (pre-existing). We have `pkt` that is the original sk_buff, and `skb` that it is allocated in this function, so IIUC we should check if `pkt` is nonlinear and copy its payload into `skb`, so we should do this (untested) chage: @@ -367,10 +367,10 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr)); if (payload_len) { - if (skb_is_nonlinear(skb)) { + if (skb_is_nonlinear(pkt)) { void *data = skb_put(skb, payload_len); - virtio_transport_copy_nonlinear_skb(skb, data, payload_len); + virtio_transport_copy_nonlinear_skb(pkt, data, payload_len); } else { skb_put_data(skb, pkt->data, payload_len); } Thanks, Stefano > } > > return skb; >-- >2.25.1
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index a1581c77cf84..05ce97b967ad 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -101,6 +101,39 @@ 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) +{ + size_t rest_len = len; + + while (rest_len && virtio_vsock_skb_has_frags(skb)) { + struct bio_vec *curr_vec; + size_t curr_vec_end; + size_t to_copy; + int curr_frag; + int curr_offs; + + curr_frag = VIRTIO_VSOCK_SKB_CB(skb)->curr_frag; + curr_offs = VIRTIO_VSOCK_SKB_CB(skb)->frag_off; + curr_vec = &skb_shinfo(skb)->frags[curr_frag]; + + curr_vec_end = curr_vec->bv_offset + curr_vec->bv_len; + to_copy = min(rest_len, (size_t)(curr_vec_end - curr_offs)); + + memcpy(dst, page_to_virt(curr_vec->bv_page) + curr_offs, + to_copy); + + rest_len -= to_copy; + VIRTIO_VSOCK_SKB_CB(skb)->frag_off += to_copy; + + if (VIRTIO_VSOCK_SKB_CB(skb)->frag_off == (curr_vec_end)) { + VIRTIO_VSOCK_SKB_CB(skb)->curr_frag++; + VIRTIO_VSOCK_SKB_CB(skb)->frag_off = 0; + } + } +} + /* Packet capture */ static struct sk_buff *virtio_transport_build_skb(void *opaque) { @@ -109,7 +142,6 @@ 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 @@ -117,7 +149,6 @@ 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); @@ -160,7 +191,13 @@ 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(skb)) { + void *data = skb_put(skb, payload_len); + + virtio_transport_copy_nonlinear_skb(skb, 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 | 43 +++++++++++++++++++++++-- 1 file changed, 40 insertions(+), 3 deletions(-)