| Message ID | c1570fa9-1673-73cf-5545-995e9aac1dbb@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 7 of 7 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 81 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 06:57:16AM +0000, Arseniy Krasnov wrote: >This adds copying to guest's virtio buffers from non-linear skbs. Such >skbs are created by protocol layer when MSG_ZEROCOPY flags is used. > >Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> >--- > drivers/vhost/vsock.c | 56 ++++++++++++++++++++++++++++++++---- > include/linux/virtio_vsock.h | 12 ++++++++ > 2 files changed, 63 insertions(+), 5 deletions(-) > >diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c >index 1f3b89c885cc..60b9cafa3e31 100644 >--- a/drivers/vhost/vsock.c >+++ b/drivers/vhost/vsock.c >@@ -86,6 +86,44 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) > return NULL; > } > >+static int vhost_transport_copy_nonlinear_skb(struct sk_buff *skb, >+ struct iov_iter *iov_iter, >+ 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)); >+ >+ if (copy_page_to_iter(curr_vec->bv_page, curr_offs, >+ to_copy, iov_iter) != to_copy) >+ return -1; >+ >+ 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; >+ } >+ } Can it happen that we exit this loop and rest_len is not 0? In this case, is it correct to decrement data_len by len? Thanks, Stefano >+ >+ skb->data_len -= len; >+ >+ return 0; >+} >+ > static void > vhost_transport_do_send_pkt(struct vhost_vsock *vsock, > struct vhost_virtqueue *vq) >@@ -197,11 +235,19 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, > break; > } > >- nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); >- if (nbytes != payload_len) { >- kfree_skb(skb); >- vq_err(vq, "Faulted on copying pkt buf\n"); >- break; >+ if (skb_is_nonlinear(skb)) { >+ if (vhost_transport_copy_nonlinear_skb(skb, &iov_iter, >+ payload_len)) { >+ vq_err(vq, "Faulted on copying pkt buf from page\n"); >+ break; >+ } >+ } else { >+ nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); >+ if (nbytes != payload_len) { >+ kfree_skb(skb); >+ vq_err(vq, "Faulted on copying pkt buf\n"); >+ break; >+ } > } > > /* Deliver to monitoring devices all packets that we >diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >index 3f9c16611306..e7efdb78ce6e 100644 >--- a/include/linux/virtio_vsock.h >+++ b/include/linux/virtio_vsock.h >@@ -12,6 +12,10 @@ > struct virtio_vsock_skb_cb { > bool reply; > bool tap_delivered; >+ /* Current fragment in 'frags' of skb. */ >+ u32 curr_frag; >+ /* Offset from 0 in current fragment. */ >+ u32 frag_off; > }; > > #define VIRTIO_VSOCK_SKB_CB(skb) ((struct virtio_vsock_skb_cb *)((skb)->cb)) >@@ -46,6 +50,14 @@ static inline void virtio_vsock_skb_clear_tap_delivered(struct sk_buff *skb) > VIRTIO_VSOCK_SKB_CB(skb)->tap_delivered = false; > } > >+static inline bool virtio_vsock_skb_has_frags(struct sk_buff *skb) >+{ >+ if (!skb_is_nonlinear(skb)) >+ return false; >+ >+ return VIRTIO_VSOCK_SKB_CB(skb)->curr_frag != skb_shinfo(skb)->nr_frags; >+} >+ > static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb) > { > u32 len; >-- >2.25.1
On 16.02.2023 17:09, Stefano Garzarella wrote: > On Mon, Feb 06, 2023 at 06:57:16AM +0000, Arseniy Krasnov wrote: >> This adds copying to guest's virtio buffers from non-linear skbs. Such >> skbs are created by protocol layer when MSG_ZEROCOPY flags is used. >> >> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> >> --- >> drivers/vhost/vsock.c | 56 ++++++++++++++++++++++++++++++++---- >> include/linux/virtio_vsock.h | 12 ++++++++ >> 2 files changed, 63 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c >> index 1f3b89c885cc..60b9cafa3e31 100644 >> --- a/drivers/vhost/vsock.c >> +++ b/drivers/vhost/vsock.c >> @@ -86,6 +86,44 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) >> return NULL; >> } >> >> +static int vhost_transport_copy_nonlinear_skb(struct sk_buff *skb, >> + struct iov_iter *iov_iter, >> + 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)); >> + >> + if (copy_page_to_iter(curr_vec->bv_page, curr_offs, >> + to_copy, iov_iter) != to_copy) >> + return -1; >> + >> + 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; >> + } >> + } > > Can it happen that we exit this loop and rest_len is not 0? > > In this case, is it correct to decrement data_len by len? I see > > Thanks, > Stefano > >> + >> + skb->data_len -= len; >> + >> + return 0; >> +} >> + >> static void >> vhost_transport_do_send_pkt(struct vhost_vsock *vsock, >> struct vhost_virtqueue *vq) >> @@ -197,11 +235,19 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, >> break; >> } >> >> - nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); >> - if (nbytes != payload_len) { >> - kfree_skb(skb); >> - vq_err(vq, "Faulted on copying pkt buf\n"); >> - break; >> + if (skb_is_nonlinear(skb)) { >> + if (vhost_transport_copy_nonlinear_skb(skb, &iov_iter, >> + payload_len)) { >> + vq_err(vq, "Faulted on copying pkt buf from page\n"); >> + break; >> + } >> + } else { >> + nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); >> + if (nbytes != payload_len) { >> + kfree_skb(skb); >> + vq_err(vq, "Faulted on copying pkt buf\n"); >> + break; >> + } >> } >> >> /* Deliver to monitoring devices all packets that we >> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >> index 3f9c16611306..e7efdb78ce6e 100644 >> --- a/include/linux/virtio_vsock.h >> +++ b/include/linux/virtio_vsock.h >> @@ -12,6 +12,10 @@ >> struct virtio_vsock_skb_cb { >> bool reply; >> bool tap_delivered; >> + /* Current fragment in 'frags' of skb. */ >> + u32 curr_frag; >> + /* Offset from 0 in current fragment. */ >> + u32 frag_off; >> }; >> >> #define VIRTIO_VSOCK_SKB_CB(skb) ((struct virtio_vsock_skb_cb *)((skb)->cb)) >> @@ -46,6 +50,14 @@ static inline void virtio_vsock_skb_clear_tap_delivered(struct sk_buff *skb) >> VIRTIO_VSOCK_SKB_CB(skb)->tap_delivered = false; >> } >> >> +static inline bool virtio_vsock_skb_has_frags(struct sk_buff *skb) >> +{ >> + if (!skb_is_nonlinear(skb)) >> + return false; >> + >> + return VIRTIO_VSOCK_SKB_CB(skb)->curr_frag != skb_shinfo(skb)->nr_frags; >> +} >> + >> static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb) >> { >> u32 len; >> -- >> 2.25.1 >
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 1f3b89c885cc..60b9cafa3e31 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -86,6 +86,44 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) return NULL; } +static int vhost_transport_copy_nonlinear_skb(struct sk_buff *skb, + struct iov_iter *iov_iter, + 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)); + + if (copy_page_to_iter(curr_vec->bv_page, curr_offs, + to_copy, iov_iter) != to_copy) + return -1; + + 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; + } + } + + skb->data_len -= len; + + return 0; +} + static void vhost_transport_do_send_pkt(struct vhost_vsock *vsock, struct vhost_virtqueue *vq) @@ -197,11 +235,19 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, break; } - nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); - if (nbytes != payload_len) { - kfree_skb(skb); - vq_err(vq, "Faulted on copying pkt buf\n"); - break; + if (skb_is_nonlinear(skb)) { + if (vhost_transport_copy_nonlinear_skb(skb, &iov_iter, + payload_len)) { + vq_err(vq, "Faulted on copying pkt buf from page\n"); + break; + } + } else { + nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); + if (nbytes != payload_len) { + kfree_skb(skb); + vq_err(vq, "Faulted on copying pkt buf\n"); + break; + } } /* Deliver to monitoring devices all packets that we diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 3f9c16611306..e7efdb78ce6e 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -12,6 +12,10 @@ struct virtio_vsock_skb_cb { bool reply; bool tap_delivered; + /* Current fragment in 'frags' of skb. */ + u32 curr_frag; + /* Offset from 0 in current fragment. */ + u32 frag_off; }; #define VIRTIO_VSOCK_SKB_CB(skb) ((struct virtio_vsock_skb_cb *)((skb)->cb)) @@ -46,6 +50,14 @@ static inline void virtio_vsock_skb_clear_tap_delivered(struct sk_buff *skb) VIRTIO_VSOCK_SKB_CB(skb)->tap_delivered = false; } +static inline bool virtio_vsock_skb_has_frags(struct sk_buff *skb) +{ + if (!skb_is_nonlinear(skb)) + return false; + + return VIRTIO_VSOCK_SKB_CB(skb)->curr_frag != skb_shinfo(skb)->nr_frags; +} + static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb) { u32 len;
This adds copying to guest's virtio buffers from non-linear skbs. Such skbs are created by protocol layer when MSG_ZEROCOPY flags is used. Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> --- drivers/vhost/vsock.c | 56 ++++++++++++++++++++++++++++++++---- include/linux/virtio_vsock.h | 12 ++++++++ 2 files changed, 63 insertions(+), 5 deletions(-)