Message ID | 20230322030308.16046-9-xuanzhuo@linux.alibaba.com (mailing list archive) |
---|---|
State | Superseded |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | virtio_net: refactor xdp codes | expand |
Context | Check | Description |
---|---|---|
netdev/series_format | success | Posting correctly formatted |
netdev/tree_selection | success | Clearly marked for net-next |
netdev/fixes_present | success | Fixes tag not required for -next series |
netdev/header_inline | success | No static functions without inline keyword in header files |
netdev/build_32bit | success | Errors and warnings before: 18 this patch: 18 |
netdev/cc_maintainers | success | CCed 13 of 13 maintainers |
netdev/build_clang | fail | Errors and warnings before: 23 this patch: 25 |
netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
netdev/deprecated_api | success | None detected |
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: 18 this patch: 18 |
netdev/checkpatch | warning | WARNING: line length of 95 exceeds 80 columns |
netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
netdev/source_inline | success | Was 0 now: 0 |
Hi Xuan,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on net-next/main]
url: https://github.com/intel-lab-lkp/linux/commits/Xuan-Zhuo/virtio_net-mergeable-xdp-put-old-page-immediately/20230322-110445
patch link: https://lore.kernel.org/r/20230322030308.16046-9-xuanzhuo%40linux.alibaba.com
patch subject: [PATCH net-next 8/8] virtio_net: introduce receive_small_xdp()
config: i386-randconfig-a002 (https://download.01.org/0day-ci/archive/20230323/202303230953.y0P1e1Fc-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/6445923dc4c91e57f98b8356d0bd706e95dafaa1
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Xuan-Zhuo/virtio_net-mergeable-xdp-put-old-page-immediately/20230322-110445
git checkout 6445923dc4c91e57f98b8356d0bd706e95dafaa1
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/net/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303230953.y0P1e1Fc-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/net/virtio_net.c:969:6: warning: variable 'buflen' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:78:22: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c:990:22: note: uninitialized use occurs here
xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
^~~~~~
drivers/net/virtio_net.c:969:2: note: remove the 'if' if its condition is always true
if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c:958:21: note: initialize the variable 'buflen' to silence this warning
unsigned int buflen;
^
= 0
drivers/net/virtio_net.c:1428:6: warning: variable 'page' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (unlikely(len > truesize - room)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:78:22: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c:1519:11: note: uninitialized use occurs here
put_page(page);
^~~~
drivers/net/virtio_net.c:1428:2: note: remove the 'if' if its condition is always false
if (unlikely(len > truesize - room)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c:1421:19: note: initialize the variable 'page' to silence this warning
struct page *page;
^
= NULL
drivers/net/virtio_net.c:1428:6: warning: variable 'num_buf' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (unlikely(len > truesize - room)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:78:22: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c:1520:25: note: uninitialized use occurs here
mergeable_buf_free(rq, num_buf, dev, stats);
^~~~~~~
drivers/net/virtio_net.c:1428:2: note: remove the 'if' if its condition is always false
if (unlikely(len > truesize - room)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c:1422:13: note: initialize the variable 'num_buf' to silence this warning
int num_buf;
^
= 0
3 warnings generated.
vim +969 drivers/net/virtio_net.c
4941d472bf95b4 Jason Wang 2017-07-19 941
6445923dc4c91e Xuan Zhuo 2023-03-22 942 static struct sk_buff *receive_small_xdp(struct net_device *dev,
bb91accf27335c Jason Wang 2016-12-23 943 struct virtnet_info *vi,
bb91accf27335c Jason Wang 2016-12-23 944 struct receive_queue *rq,
6445923dc4c91e Xuan Zhuo 2023-03-22 945 struct bpf_prog *xdp_prog,
6445923dc4c91e Xuan Zhuo 2023-03-22 946 void *buf,
6445923dc4c91e Xuan Zhuo 2023-03-22 947 void *ctx,
186b3c998c50fc Jason Wang 2017-09-19 948 unsigned int len,
7d9d60fd4ab696 Toshiaki Makita 2018-07-23 949 unsigned int *xdp_xmit,
d46eeeaf99bcfa Jason Wang 2018-07-31 950 struct virtnet_rq_stats *stats)
f121159d72091f Michael S. Tsirkin 2013-11-28 951 {
4941d472bf95b4 Jason Wang 2017-07-19 952 unsigned int xdp_headroom = (unsigned long)ctx;
f6b10209b90d48 Jason Wang 2017-02-21 953 unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
f6b10209b90d48 Jason Wang 2017-02-21 954 unsigned int headroom = vi->hdr_len + header_offset;
6445923dc4c91e Xuan Zhuo 2023-03-22 955 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
4941d472bf95b4 Jason Wang 2017-07-19 956 struct page *page = virt_to_head_page(buf);
4941d472bf95b4 Jason Wang 2017-07-19 957 struct page *xdp_page;
6445923dc4c91e Xuan Zhuo 2023-03-22 958 unsigned int buflen;
0354e4d19cd5de John Fastabend 2017-02-02 959 struct xdp_buff xdp;
6445923dc4c91e Xuan Zhuo 2023-03-22 960 struct sk_buff *skb;
6445923dc4c91e Xuan Zhuo 2023-03-22 961 unsigned int delta = 0;
6445923dc4c91e Xuan Zhuo 2023-03-22 962 unsigned int metasize = 0;
f6b10209b90d48 Jason Wang 2017-02-21 963 void *orig_data;
bb91accf27335c Jason Wang 2016-12-23 964 u32 act;
bb91accf27335c Jason Wang 2016-12-23 965
95dbe9e7b3720e Jesper Dangaard Brouer 2018-02-20 966 if (unlikely(hdr->hdr.gso_type))
bb91accf27335c Jason Wang 2016-12-23 967 goto err_xdp;
0354e4d19cd5de John Fastabend 2017-02-02 968
4941d472bf95b4 Jason Wang 2017-07-19 @969 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
4941d472bf95b4 Jason Wang 2017-07-19 970 int offset = buf - page_address(page) + header_offset;
4941d472bf95b4 Jason Wang 2017-07-19 971 unsigned int tlen = len + vi->hdr_len;
981f14d42a7f16 Heng Qi 2023-01-31 972 int num_buf = 1;
4941d472bf95b4 Jason Wang 2017-07-19 973
4941d472bf95b4 Jason Wang 2017-07-19 974 xdp_headroom = virtnet_get_headroom(vi);
4941d472bf95b4 Jason Wang 2017-07-19 975 header_offset = VIRTNET_RX_PAD + xdp_headroom;
4941d472bf95b4 Jason Wang 2017-07-19 976 headroom = vi->hdr_len + header_offset;
4941d472bf95b4 Jason Wang 2017-07-19 977 buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
4941d472bf95b4 Jason Wang 2017-07-19 978 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4941d472bf95b4 Jason Wang 2017-07-19 979 xdp_page = xdp_linearize_page(rq, &num_buf, page,
4941d472bf95b4 Jason Wang 2017-07-19 980 offset, header_offset,
4941d472bf95b4 Jason Wang 2017-07-19 981 &tlen);
4941d472bf95b4 Jason Wang 2017-07-19 982 if (!xdp_page)
4941d472bf95b4 Jason Wang 2017-07-19 983 goto err_xdp;
4941d472bf95b4 Jason Wang 2017-07-19 984
4941d472bf95b4 Jason Wang 2017-07-19 985 buf = page_address(xdp_page);
4941d472bf95b4 Jason Wang 2017-07-19 986 put_page(page);
4941d472bf95b4 Jason Wang 2017-07-19 987 page = xdp_page;
4941d472bf95b4 Jason Wang 2017-07-19 988 }
4941d472bf95b4 Jason Wang 2017-07-19 989
43b5169d8355cc Lorenzo Bianconi 2020-12-22 990 xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
be9df4aff65f18 Lorenzo Bianconi 2020-12-22 991 xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
be9df4aff65f18 Lorenzo Bianconi 2020-12-22 992 xdp_headroom, len, true);
f6b10209b90d48 Jason Wang 2017-02-21 993 orig_data = xdp.data;
4249e276b1ab30 Xuan Zhuo 2023-03-22 994
4249e276b1ab30 Xuan Zhuo 2023-03-22 995 act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
0354e4d19cd5de John Fastabend 2017-02-02 996
bb91accf27335c Jason Wang 2016-12-23 997 switch (act) {
4249e276b1ab30 Xuan Zhuo 2023-03-22 998 case VIRTNET_XDP_RES_PASS:
2de2f7f40ef923 John Fastabend 2017-02-02 999 /* Recalculate length in case bpf program changed it */
f6b10209b90d48 Jason Wang 2017-02-21 1000 delta = orig_data - xdp.data;
6870de435b90c0 Nikita V. Shirokov 2018-04-17 1001 len = xdp.data_end - xdp.data;
503d539a6e417b Yuya Kusakabe 2020-02-25 1002 metasize = xdp.data - xdp.data_meta;
bb91accf27335c Jason Wang 2016-12-23 1003 break;
4249e276b1ab30 Xuan Zhuo 2023-03-22 1004
4249e276b1ab30 Xuan Zhuo 2023-03-22 1005 case VIRTNET_XDP_RES_CONSUMED:
bb91accf27335c Jason Wang 2016-12-23 1006 goto xdp_xmit;
4249e276b1ab30 Xuan Zhuo 2023-03-22 1007
4249e276b1ab30 Xuan Zhuo 2023-03-22 1008 case VIRTNET_XDP_RES_DROP:
bb91accf27335c Jason Wang 2016-12-23 1009 goto err_xdp;
bb91accf27335c Jason Wang 2016-12-23 1010 }
bb91accf27335c Jason Wang 2016-12-23 1011
f6b10209b90d48 Jason Wang 2017-02-21 1012 skb = build_skb(buf, buflen);
053c9e18c6f9cf Wenliang Wang 2021-12-16 1013 if (!skb)
f6b10209b90d48 Jason Wang 2017-02-21 1014 goto err;
6445923dc4c91e Xuan Zhuo 2023-03-22 1015
f6b10209b90d48 Jason Wang 2017-02-21 1016 skb_reserve(skb, headroom - delta);
6870de435b90c0 Nikita V. Shirokov 2018-04-17 1017 skb_put(skb, len);
503d539a6e417b Yuya Kusakabe 2020-02-25 1018 if (metasize)
503d539a6e417b Yuya Kusakabe 2020-02-25 1019 skb_metadata_set(skb, metasize);
503d539a6e417b Yuya Kusakabe 2020-02-25 1020
f121159d72091f Michael S. Tsirkin 2013-11-28 1021 return skb;
bb91accf27335c Jason Wang 2016-12-23 1022
bb91accf27335c Jason Wang 2016-12-23 1023 err_xdp:
d46eeeaf99bcfa Jason Wang 2018-07-31 1024 stats->xdp_drops++;
053c9e18c6f9cf Wenliang Wang 2021-12-16 1025 err:
d46eeeaf99bcfa Jason Wang 2018-07-31 1026 stats->drops++;
4941d472bf95b4 Jason Wang 2017-07-19 1027 put_page(page);
bb91accf27335c Jason Wang 2016-12-23 1028 xdp_xmit:
bb91accf27335c Jason Wang 2016-12-23 1029 return NULL;
f121159d72091f Michael S. Tsirkin 2013-11-28 1030 }
f121159d72091f Michael S. Tsirkin 2013-11-28 1031
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6ecb17e972e1..23b1a6fd1224 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -939,6 +939,96 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, return NULL; } +static struct sk_buff *receive_small_xdp(struct net_device *dev, + struct virtnet_info *vi, + struct receive_queue *rq, + struct bpf_prog *xdp_prog, + void *buf, + void *ctx, + unsigned int len, + unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats) +{ + unsigned int xdp_headroom = (unsigned long)ctx; + unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom; + unsigned int headroom = vi->hdr_len + header_offset; + struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; + struct page *page = virt_to_head_page(buf); + struct page *xdp_page; + unsigned int buflen; + struct xdp_buff xdp; + struct sk_buff *skb; + unsigned int delta = 0; + unsigned int metasize = 0; + void *orig_data; + u32 act; + + if (unlikely(hdr->hdr.gso_type)) + goto err_xdp; + + if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { + int offset = buf - page_address(page) + header_offset; + unsigned int tlen = len + vi->hdr_len; + int num_buf = 1; + + xdp_headroom = virtnet_get_headroom(vi); + header_offset = VIRTNET_RX_PAD + xdp_headroom; + headroom = vi->hdr_len + header_offset; + buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + xdp_page = xdp_linearize_page(rq, &num_buf, page, + offset, header_offset, + &tlen); + if (!xdp_page) + goto err_xdp; + + buf = page_address(xdp_page); + put_page(page); + page = xdp_page; + } + + xdp_init_buff(&xdp, buflen, &rq->xdp_rxq); + xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, + xdp_headroom, len, true); + orig_data = xdp.data; + + act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); + + switch (act) { + case VIRTNET_XDP_RES_PASS: + /* Recalculate length in case bpf program changed it */ + delta = orig_data - xdp.data; + len = xdp.data_end - xdp.data; + metasize = xdp.data - xdp.data_meta; + break; + + case VIRTNET_XDP_RES_CONSUMED: + goto xdp_xmit; + + case VIRTNET_XDP_RES_DROP: + goto err_xdp; + } + + skb = build_skb(buf, buflen); + if (!skb) + goto err; + + skb_reserve(skb, headroom - delta); + skb_put(skb, len); + if (metasize) + skb_metadata_set(skb, metasize); + + return skb; + +err_xdp: + stats->xdp_drops++; +err: + stats->drops++; + put_page(page); +xdp_xmit: + return NULL; +} + static struct sk_buff *receive_small(struct net_device *dev, struct virtnet_info *vi, struct receive_queue *rq, @@ -949,15 +1039,11 @@ static struct sk_buff *receive_small(struct net_device *dev, { struct sk_buff *skb; struct bpf_prog *xdp_prog; - unsigned int xdp_headroom = (unsigned long)ctx; - unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom; + unsigned int header_offset = VIRTNET_RX_PAD; unsigned int headroom = vi->hdr_len + header_offset; unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); struct page *page = virt_to_head_page(buf); - unsigned int delta = 0; - struct page *xdp_page; - unsigned int metasize = 0; len -= vi->hdr_len; stats->bytes += len; @@ -977,57 +1063,9 @@ static struct sk_buff *receive_small(struct net_device *dev, rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (xdp_prog) { - struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; - struct xdp_buff xdp; - void *orig_data; - u32 act; - - if (unlikely(hdr->hdr.gso_type)) - goto err_xdp; - - if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { - int offset = buf - page_address(page) + header_offset; - unsigned int tlen = len + vi->hdr_len; - int num_buf = 1; - - xdp_headroom = virtnet_get_headroom(vi); - header_offset = VIRTNET_RX_PAD + xdp_headroom; - headroom = vi->hdr_len + header_offset; - buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - xdp_page = xdp_linearize_page(rq, &num_buf, page, - offset, header_offset, - &tlen); - if (!xdp_page) - goto err_xdp; - - buf = page_address(xdp_page); - put_page(page); - page = xdp_page; - } - - xdp_init_buff(&xdp, buflen, &rq->xdp_rxq); - xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, - xdp_headroom, len, true); - orig_data = xdp.data; - - act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); - - switch (act) { - case VIRTNET_XDP_RES_PASS: - /* Recalculate length in case bpf program changed it */ - delta = orig_data - xdp.data; - len = xdp.data_end - xdp.data; - metasize = xdp.data - xdp.data_meta; - break; - - case VIRTNET_XDP_RES_CONSUMED: - rcu_read_unlock(); - goto xdp_xmit; - - case VIRTNET_XDP_RES_DROP: - goto err_xdp; - } + skb = receive_small_xdp(dev, vi, rq, xdp_prog, buf, ctx, len, xdp_xmit, stats); + rcu_read_unlock(); + return skb; } rcu_read_unlock(); @@ -1035,25 +1073,16 @@ static struct sk_buff *receive_small(struct net_device *dev, skb = build_skb(buf, buflen); if (!skb) goto err; - skb_reserve(skb, headroom - delta); + skb_reserve(skb, headroom); skb_put(skb, len); - if (!xdp_prog) { - buf += header_offset; - memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); - } /* keep zeroed vnet hdr since XDP is loaded */ - - if (metasize) - skb_metadata_set(skb, metasize); + buf += header_offset; + memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); return skb; -err_xdp: - rcu_read_unlock(); - stats->xdp_drops++; err: stats->drops++; put_page(page); -xdp_xmit: return NULL; }
The purpose of this patch is to simplify the receive_small(). Separate all the logic of XDP of small into a function. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/net/virtio_net.c | 165 +++++++++++++++++++++++---------------- 1 file changed, 97 insertions(+), 68 deletions(-)