* [PATCH net-next v10 0/3] xen networking: add XDP support to xen-netfront
@ 2020-06-22 9:21 Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 1/3] xen: netif.h: add a new extra type for XDP Denis Kirjanov
` (2 more replies)
0 siblings, 3 replies; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 9:21 UTC (permalink / raw)
To: netdev; +Cc: brouer, jgross, wei.liu, paul, ilias.apalodimas
The first patch adds a new extra type to enable proper synchronization
between an RX request/response pair.
The second patch implements BFP interface for xen-netfront.
The third patch enables extra space for XDP processing.
v10:
- add a new xen_netif_extra_info type to enable proper synchronization
between an RX request/response pair.
- order local variable declarations
v9:
- assign an xdp program before switching to Reconfiguring
- minor cleanups
- address checkpatch issues
v8:
- add PAGE_POOL config dependency
- keep the state of XDP processing in netfront_xdp_enabled
- fixed allocator type in xdp_rxq_info_reg_mem_model()
- minor cleanups in xen-netback
v7:
- use page_pool_dev_alloc_pages() on page allocation
- remove the leftover break statement from netback_changed
v6:
- added the missing SOB line
- fixed subject
v5:
- split netfront/netback changes
- added a sync point between backend/frontend on switching to XDP
- added pagepool API
v4:
- added verbose patch descriprion
- don't expose the XDP headroom offset to the domU guest
- add a modparam to netback to toggle XDP offset
- don't process jumbo frames for now
v3:
- added XDP_TX support (tested with xdping echoserver)
- added XDP_REDIRECT support (tested with modified xdp_redirect_kern)
- moved xdp negotiation to xen-netback
v2:
- avoid data copying while passing to XDP
- tell xen-netback that we need the headroom space
Denis Kirjanov (3):
xen: netif.h: add a new extra type for XDP
xen networking: add basic XDP support for xen-netfront
xen networking: add XDP offset adjustment to xen-netback
drivers/net/Kconfig | 1 +
drivers/net/xen-netback/common.h | 4 +
drivers/net/xen-netback/interface.c | 2 +
drivers/net/xen-netback/netback.c | 7 +
drivers/net/xen-netback/rx.c | 15 +-
drivers/net/xen-netback/xenbus.c | 32 ++++
drivers/net/xen-netfront.c | 332 ++++++++++++++++++++++++++++++++++--
include/xen/interface/io/netif.h | 18 +-
8 files changed, 399 insertions(+), 12 deletions(-)
--
1.8.3.1
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH net-next v10 1/3] xen: netif.h: add a new extra type for XDP
2020-06-22 9:21 [PATCH net-next v10 0/3] xen networking: add XDP support to xen-netfront Denis Kirjanov
@ 2020-06-22 9:21 ` Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback Denis Kirjanov
2 siblings, 0 replies; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 9:21 UTC (permalink / raw)
To: netdev; +Cc: brouer, jgross, wei.liu, paul, ilias.apalodimas
The patch adds a new extra type to be able to diffirentiate
between RX responses on xen-netfront side with the adjusted offset
required for XDP processing.
The offset value from a guest is passed via xenstore.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
---
include/xen/interface/io/netif.h | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/xen/interface/io/netif.h b/include/xen/interface/io/netif.h
index 4f20dbc..c35a5165 100644
--- a/include/xen/interface/io/netif.h
+++ b/include/xen/interface/io/netif.h
@@ -161,6 +161,17 @@
*/
/*
+ * "xdp-headroom" is used to request that extra space is added
+ * for XDP processing. The value is measured in bytes and passed by
+ * the frontend to be consistent between both ends.
+ * If the value is greater than zero that means that
+ * an RX response is going to be passed to an XDP program for processing.
+ *
+ * "feature-xdp-headroom" is set to "1" by the netback side like other features
+ * so a guest can check if an XDP program can be processed.
+ */
+
+/*
* Control ring
* ============
*
@@ -846,7 +857,8 @@ struct xen_netif_tx_request {
#define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2) /* u.mcast */
#define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3) /* u.mcast */
#define XEN_NETIF_EXTRA_TYPE_HASH (4) /* u.hash */
-#define XEN_NETIF_EXTRA_TYPE_MAX (5)
+#define XEN_NETIF_EXTRA_TYPE_XDP (5) /* u.xdp */
+#define XEN_NETIF_EXTRA_TYPE_MAX (6)
/* xen_netif_extra_info_t flags. */
#define _XEN_NETIF_EXTRA_FLAG_MORE (0)
@@ -879,6 +891,10 @@ struct xen_netif_extra_info {
uint8_t algorithm;
uint8_t value[4];
} hash;
+ struct {
+ uint16_t headroom;
+ uint16_t pad[2];
+ } xdp;
uint16_t pad[3];
} u;
};
--
1.8.3.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
2020-06-22 9:21 [PATCH net-next v10 0/3] xen networking: add XDP support to xen-netfront Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 1/3] xen: netif.h: add a new extra type for XDP Denis Kirjanov
@ 2020-06-22 9:21 ` Denis Kirjanov
2020-06-22 9:58 ` Jesper Dangaard Brouer
2020-06-22 12:34 ` kernel test robot
2020-06-22 9:21 ` [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback Denis Kirjanov
2 siblings, 2 replies; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 9:21 UTC (permalink / raw)
To: netdev; +Cc: brouer, jgross, wei.liu, paul, ilias.apalodimas
The patch adds a basic XDP processing to xen-netfront driver.
We ran an XDP program for an RX response received from netback
driver. Also we request xen-netback to adjust data offset for
bpf_xdp_adjust_head() header space for custom headers.
synchronization between frontend and backend parts is done
by using xenbus state switching:
Reconfiguring -> Reconfigured- > Connected
UDP packets drop rate using xdp program is around 310 kpps
using ./pktgen_sample04_many_flows.sh and 160 kpps without the patch.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
---
drivers/net/Kconfig | 1 +
drivers/net/xen-netfront.c | 332 +++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 323 insertions(+), 10 deletions(-)
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 25a8f93..45918ce 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -479,6 +479,7 @@ config XEN_NETDEV_FRONTEND
tristate "Xen network device frontend driver"
depends on XEN
select XEN_XENBUS_FRONTEND
+ select PAGE_POOL
default y
help
This driver provides support for Xen paravirtual network
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 482c6c8..1b9f49e 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -44,6 +44,9 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <net/ip.h>
+#include <linux/bpf.h>
+#include <net/page_pool.h>
+#include <linux/bpf_trace.h>
#include <xen/xen.h>
#include <xen/xenbus.h>
@@ -102,6 +105,8 @@ struct netfront_queue {
char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
struct netfront_info *info;
+ struct bpf_prog __rcu *xdp_prog;
+
struct napi_struct napi;
/* Split event channels support, tx_* == rx_* when using
@@ -144,6 +149,9 @@ struct netfront_queue {
struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
grant_ref_t gref_rx_head;
grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
+
+ struct page_pool *page_pool;
+ struct xdp_rxq_info xdp_rxq;
};
struct netfront_info {
@@ -159,6 +167,10 @@ struct netfront_info {
struct netfront_stats __percpu *rx_stats;
struct netfront_stats __percpu *tx_stats;
+ /* XDP state */
+ bool netback_has_xdp_headroom;
+ bool netfront_xdp_enabled;
+
atomic_t rx_gso_checksum_fixup;
};
@@ -265,8 +277,8 @@ static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
if (unlikely(!skb))
return NULL;
- page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
- if (!page) {
+ page = page_pool_dev_alloc_pages(queue->page_pool);
+ if (unlikely(!page)) {
kfree_skb(skb);
return NULL;
}
@@ -560,6 +572,65 @@ static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
return queue_idx;
}
+static int xennet_xdp_xmit_one(struct net_device *dev, struct xdp_frame *xdpf)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
+ unsigned int num_queues = dev->real_num_tx_queues;
+ struct netfront_queue *queue = NULL;
+ struct xen_netif_tx_request *tx;
+ unsigned long flags;
+ int notify;
+
+ queue = &np->queues[smp_processor_id() % num_queues];
+
+ spin_lock_irqsave(&queue->tx_lock, flags);
+
+ tx = xennet_make_first_txreq(queue, NULL,
+ virt_to_page(xdpf->data),
+ offset_in_page(xdpf->data),
+ xdpf->len);
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
+ if (notify)
+ notify_remote_via_irq(queue->tx_irq);
+
+ u64_stats_update_begin(&tx_stats->syncp);
+ tx_stats->bytes += xdpf->len;
+ tx_stats->packets++;
+ u64_stats_update_end(&tx_stats->syncp);
+
+ xennet_tx_buf_gc(queue);
+
+ spin_unlock_irqrestore(&queue->tx_lock, flags);
+ return 0;
+}
+
+static int xennet_xdp_xmit(struct net_device *dev, int n,
+ struct xdp_frame **frames, u32 flags)
+{
+ int drops = 0;
+ int i, err;
+
+ if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+ return -EINVAL;
+
+ for (i = 0; i < n; i++) {
+ struct xdp_frame *xdpf = frames[i];
+
+ if (!xdpf)
+ continue;
+ err = xennet_xdp_xmit_one(dev, xdpf);
+ if (err) {
+ xdp_return_frame_rx_napi(xdpf);
+ drops++;
+ }
+ }
+
+ return n - drops;
+}
+
+
#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -778,23 +849,81 @@ static int xennet_get_extras(struct netfront_queue *queue,
return err;
}
+static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
+ struct xen_netif_rx_response *rx, struct bpf_prog *prog,
+ struct xdp_buff *xdp, bool *need_xdp_flush)
+{
+ struct xdp_frame *xdpf;
+ u32 len = rx->status;
+ u32 act = XDP_PASS;
+ int err;
+
+ xdp->data_hard_start = page_address(pdata);
+ xdp->data = xdp->data_hard_start + XDP_PACKET_HEADROOM;
+ xdp_set_data_meta_invalid(xdp);
+ xdp->data_end = xdp->data + len;
+ xdp->rxq = &queue->xdp_rxq;
+
+ act = bpf_prog_run_xdp(prog, xdp);
+ switch (act) {
+ case XDP_TX:
+ get_page(pdata);
+ xdpf = convert_to_xdp_frame(xdp);
+ err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
+ if (unlikely(err < 0))
+ trace_xdp_exception(queue->info->netdev, prog, act);
+ break;
+ case XDP_REDIRECT:
+ get_page(pdata);
+ err = xdp_do_redirect(queue->info->netdev, xdp, prog);
+ *need_xdp_flush = true;
+ if (unlikely(err))
+ trace_xdp_exception(queue->info->netdev, prog, act);
+ break;
+ case XDP_PASS:
+ case XDP_DROP:
+ break;
+
+ case XDP_ABORTED:
+ trace_xdp_exception(queue->info->netdev, prog, act);
+ break;
+
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ }
+
+ return act;
+}
+
static int xennet_get_responses(struct netfront_queue *queue,
struct netfront_rx_info *rinfo, RING_IDX rp,
- struct sk_buff_head *list)
+ struct sk_buff_head *list,
+ bool *need_xdp_flush)
{
struct xen_netif_rx_response *rx = &rinfo->rx;
- struct xen_netif_extra_info *extras = rinfo->extras;
- struct device *dev = &queue->info->netdev->dev;
+ int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
RING_IDX cons = queue->rx.rsp_cons;
struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
+ struct xen_netif_extra_info *extras = rinfo->extras;
grant_ref_t ref = xennet_get_rx_ref(queue, cons);
- int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
+ struct device *dev = &queue->info->netdev->dev;
+ struct bpf_prog *xdp_prog;
+ struct xdp_buff xdp;
+ unsigned long ret;
int slots = 1;
int err = 0;
- unsigned long ret;
+ u32 verdict;
if (rx->flags & XEN_NETRXF_extra_info) {
err = xennet_get_extras(queue, extras, rp);
+ if (!err) {
+ if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) {
+ struct xen_netif_extra_info *xdp;
+
+ xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
+ rx->offset = xdp->u.xdp.headroom;
+ }
+ }
cons = queue->rx.rsp_cons;
}
@@ -827,9 +956,24 @@ static int xennet_get_responses(struct netfront_queue *queue,
gnttab_release_grant_reference(&queue->gref_rx_head, ref);
- __skb_queue_tail(list, skb);
-
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(queue->xdp_prog);
+ if (xdp_prog) {
+ if (!(rx->flags & XEN_NETRXF_more_data)) {
+ /* currently only a single page contains data */
+ verdict = xennet_run_xdp(queue,
+ skb_frag_page(&skb_shinfo(skb)->frags[0]),
+ rx, xdp_prog, &xdp, need_xdp_flush);
+ if (verdict != XDP_PASS)
+ err = -EINVAL;
+ } else {
+ /* drop the frame */
+ err = -EINVAL;
+ }
+ }
+ rcu_read_unlock();
next:
+ __skb_queue_tail(list, skb);
if (!(rx->flags & XEN_NETRXF_more_data))
break;
@@ -998,6 +1142,7 @@ static int xennet_poll(struct napi_struct *napi, int budget)
struct sk_buff_head errq;
struct sk_buff_head tmpq;
int err;
+ bool need_xdp_flush = false;
spin_lock(&queue->rx_lock);
@@ -1014,7 +1159,8 @@ static int xennet_poll(struct napi_struct *napi, int budget)
memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
memset(extras, 0, sizeof(rinfo.extras));
- err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
+ err = xennet_get_responses(queue, &rinfo, rp, &tmpq,
+ &need_xdp_flush);
if (unlikely(err)) {
err:
@@ -1060,6 +1206,8 @@ static int xennet_poll(struct napi_struct *napi, int budget)
i = ++queue->rx.rsp_cons;
work_done++;
}
+ if (need_xdp_flush)
+ xdp_do_flush();
__skb_queue_purge(&errq);
@@ -1261,6 +1409,99 @@ static void xennet_poll_controller(struct net_device *dev)
}
#endif
+#define NETBACK_XDP_HEADROOM_DISABLE 0
+#define NETBACK_XDP_HEADROOM_ENABLE 1
+
+static int talk_to_netback_xdp(struct netfront_info *np, int xdp)
+{
+ int err;
+
+ err = xenbus_printf(XBT_NIL, np->xbdev->nodename,
+ "netfront-xdp-headroom", "%hu",
+ xdp ? XDP_PACKET_HEADROOM : 0);
+ if (err)
+ pr_warn("Error writing netfront-xdp-headroom\n");
+
+ return err;
+}
+
+static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+ struct netlink_ext_ack *extack)
+{
+ unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
+ struct netfront_info *np = netdev_priv(dev);
+ struct bpf_prog *old_prog;
+ unsigned int i, err;
+
+ if (dev->mtu > max_mtu) {
+ netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu);
+ return -EINVAL;
+ }
+
+ if (!np->netback_has_xdp_headroom)
+ return 0;
+
+ xenbus_switch_state(np->xbdev, XenbusStateReconfiguring);
+
+ err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE :
+ NETBACK_XDP_HEADROOM_DISABLE);
+ if (err)
+ return err;
+
+ /* avoid the race with XDP headroom adjustment */
+ wait_event(module_wq,
+ xenbus_read_driver_state(np->xbdev->otherend) ==
+ XenbusStateReconfigured);
+ np->netfront_xdp_enabled = true;
+
+ old_prog = rtnl_dereference(np->queues[0].xdp_prog);
+
+ if (prog)
+ bpf_prog_add(prog, dev->real_num_tx_queues);
+
+ for (i = 0; i < dev->real_num_tx_queues; ++i)
+ rcu_assign_pointer(np->queues[i].xdp_prog, prog);
+
+ if (old_prog)
+ for (i = 0; i < dev->real_num_tx_queues; ++i)
+ bpf_prog_put(old_prog);
+
+ xenbus_switch_state(np->xbdev, XenbusStateConnected);
+
+ return 0;
+}
+
+static u32 xennet_xdp_query(struct net_device *dev)
+{
+ unsigned int num_queues = dev->real_num_tx_queues;
+ struct netfront_info *np = netdev_priv(dev);
+ const struct bpf_prog *xdp_prog;
+ struct netfront_queue *queue;
+ unsigned int i;
+
+ for (i = 0; i < num_queues; ++i) {
+ queue = &np->queues[i];
+ xdp_prog = rtnl_dereference(queue->xdp_prog);
+ if (xdp_prog)
+ return xdp_prog->aux->id;
+ }
+
+ return 0;
+}
+
+static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ switch (xdp->command) {
+ case XDP_SETUP_PROG:
+ return xennet_xdp_set(dev, xdp->prog, xdp->extack);
+ case XDP_QUERY_PROG:
+ xdp->prog_id = xennet_xdp_query(dev);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
static const struct net_device_ops xennet_netdev_ops = {
.ndo_open = xennet_open,
.ndo_stop = xennet_close,
@@ -1272,6 +1513,8 @@ static void xennet_poll_controller(struct net_device *dev)
.ndo_fix_features = xennet_fix_features,
.ndo_set_features = xennet_set_features,
.ndo_select_queue = xennet_select_queue,
+ .ndo_bpf = xennet_xdp,
+ .ndo_xdp_xmit = xennet_xdp_xmit,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = xennet_poll_controller,
#endif
@@ -1331,6 +1574,7 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
SET_NETDEV_DEV(netdev, &dev->dev);
np->netdev = netdev;
+ np->netfront_xdp_enabled = false;
netif_carrier_off(netdev);
@@ -1419,6 +1663,8 @@ static void xennet_disconnect_backend(struct netfront_info *info)
queue->rx_ring_ref = GRANT_INVALID_REF;
queue->tx.sring = NULL;
queue->rx.sring = NULL;
+
+ page_pool_destroy(queue->page_pool);
}
}
@@ -1754,6 +2000,51 @@ static void xennet_destroy_queues(struct netfront_info *info)
info->queues = NULL;
}
+
+
+static int xennet_create_page_pool(struct netfront_queue *queue)
+{
+ int err;
+ struct page_pool_params pp_params = {
+ .order = 0,
+ .flags = 0,
+ .pool_size = NET_RX_RING_SIZE,
+ .nid = NUMA_NO_NODE,
+ .dev = &queue->info->netdev->dev,
+ .offset = XDP_PACKET_HEADROOM,
+ .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
+ };
+
+ queue->page_pool = page_pool_create(&pp_params);
+ if (IS_ERR(queue->page_pool)) {
+ err = PTR_ERR(queue->page_pool);
+ queue->page_pool = NULL;
+ return err;
+ }
+
+ err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
+ queue->id);
+ if (err) {
+ netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
+ goto err_free_pp;
+ }
+
+ err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
+ MEM_TYPE_PAGE_POOL, queue->page_pool);
+ if (err) {
+ netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n");
+ goto err_unregister_rxq;
+ }
+ return 0;
+
+err_unregister_rxq:
+ xdp_rxq_info_unreg(&queue->xdp_rxq);
+err_free_pp:
+ page_pool_destroy(queue->page_pool);
+ queue->page_pool = NULL;
+ return err;
+}
+
static int xennet_create_queues(struct netfront_info *info,
unsigned int *num_queues)
{
@@ -1779,6 +2070,14 @@ static int xennet_create_queues(struct netfront_info *info,
break;
}
+ /* use page pool recycling instead of buddy allocator */
+ ret = xennet_create_page_pool(queue);
+ if (ret < 0) {
+ dev_err(&info->xbdev->dev, "can't allocate page pool\n");
+ *num_queues = i;
+ return ret;
+ }
+
netif_napi_add(queue->info->netdev, &queue->napi,
xennet_poll, 64);
if (netif_running(info->netdev))
@@ -1825,6 +2124,17 @@ static int talk_to_netback(struct xenbus_device *dev,
goto out_unlocked;
}
+ info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
+ "feature-xdp-headroom", 0);
+ if (info->netback_has_xdp_headroom) {
+ /* set the current xen-netfront xdp state */
+ err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ?
+ NETBACK_XDP_HEADROOM_ENABLE :
+ NETBACK_XDP_HEADROOM_DISABLE);
+ if (err)
+ goto out_unlocked;
+ }
+
rtnl_lock();
if (info->queues)
xennet_destroy_queues(info);
@@ -1959,6 +2269,8 @@ static int xennet_connect(struct net_device *dev)
err = talk_to_netback(np->xbdev, np);
if (err)
return err;
+ if (np->netback_has_xdp_headroom)
+ pr_info("backend supports XDP headroom\n");
/* talk_to_netback() sets the correct number of queues */
num_queues = dev->real_num_tx_queues;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback
2020-06-22 9:21 [PATCH net-next v10 0/3] xen networking: add XDP support to xen-netfront Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 1/3] xen: netif.h: add a new extra type for XDP Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront Denis Kirjanov
@ 2020-06-22 9:21 ` Denis Kirjanov
2020-06-22 10:10 ` Paul Durrant
2 siblings, 1 reply; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 9:21 UTC (permalink / raw)
To: netdev; +Cc: brouer, jgross, wei.liu, paul, ilias.apalodimas
the patch basically adds the offset adjustment and netfront
state reading to make XDP work on netfront side.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
---
drivers/net/xen-netback/common.h | 4 ++++
drivers/net/xen-netback/interface.c | 2 ++
drivers/net/xen-netback/netback.c | 7 +++++++
drivers/net/xen-netback/rx.c | 15 ++++++++++++++-
drivers/net/xen-netback/xenbus.c | 32 ++++++++++++++++++++++++++++++++
5 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 05847eb..f14dc10 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -281,6 +281,9 @@ struct xenvif {
u8 ipv6_csum:1;
u8 multicast_control:1;
+ /* headroom requested by xen-netfront */
+ u16 netfront_xdp_headroom;
+
/* Is this interface disabled? True when backend discovers
* frontend is rogue.
*/
@@ -395,6 +398,7 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
irqreturn_t xenvif_interrupt(int irq, void *dev_id);
extern bool separate_tx_rx_irq;
+extern bool provides_xdp_headroom;
extern unsigned int rx_drain_timeout_msecs;
extern unsigned int rx_stall_timeout_msecs;
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 0c8a02a..fc16edd 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -483,6 +483,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
vif->queues = NULL;
vif->num_queues = 0;
+ vif->netfront_xdp_headroom = 0;
+
spin_lock_init(&vif->lock);
INIT_LIST_HEAD(&vif->fe_mcast_addr);
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 315dfc6..6dfca72 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -96,6 +96,13 @@
module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
+/* The module parameter tells that we have to put data
+ * for xen-netfront with the XDP_PACKET_HEADROOM offset
+ * needed for XDP processing
+ */
+bool provides_xdp_headroom = true;
+module_param(provides_xdp_headroom, bool, 0644);
+
static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
u8 status);
diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
index ef58870..c5e9e14 100644
--- a/drivers/net/xen-netback/rx.c
+++ b/drivers/net/xen-netback/rx.c
@@ -258,6 +258,19 @@ static void xenvif_rx_next_skb(struct xenvif_queue *queue,
pkt->extra_count++;
}
+ if (queue->vif->netfront_xdp_headroom) {
+ struct xen_netif_extra_info *extra;
+
+ extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
+
+ memset(extra, 0, sizeof(struct xen_netif_extra_info));
+ extra->u.xdp.headroom = queue->vif->netfront_xdp_headroom;
+ extra->type = XEN_NETIF_EXTRA_TYPE_XDP;
+ extra->flags = 0;
+
+ pkt->extra_count++;
+ }
+
if (skb->sw_hash) {
struct xen_netif_extra_info *extra;
@@ -356,7 +369,7 @@ static void xenvif_rx_data_slot(struct xenvif_queue *queue,
struct xen_netif_rx_request *req,
struct xen_netif_rx_response *rsp)
{
- unsigned int offset = 0;
+ unsigned int offset = queue->vif->netfront_xdp_headroom;
unsigned int flags;
do {
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 286054b..c67abc5 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -393,6 +393,22 @@ static void set_backend_state(struct backend_info *be,
}
}
+static void read_xenbus_frontend_xdp(struct backend_info *be,
+ struct xenbus_device *dev)
+{
+ struct xenvif *vif = be->vif;
+ u16 headroom;
+ int err;
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend,
+ "netfront-xdp-headroom", "%hu", &headroom);
+ if (err < 0) {
+ vif->netfront_xdp_headroom = 0;
+ return;
+ }
+ vif->netfront_xdp_headroom = headroom;
+}
+
/**
* Callback received when the frontend's state changes.
*/
@@ -417,6 +433,11 @@ static void frontend_changed(struct xenbus_device *dev,
set_backend_state(be, XenbusStateConnected);
break;
+ case XenbusStateReconfiguring:
+ read_xenbus_frontend_xdp(be, dev);
+ xenbus_switch_state(dev, XenbusStateReconfigured);
+ break;
+
case XenbusStateClosing:
set_backend_state(be, XenbusStateClosing);
break;
@@ -947,6 +968,8 @@ static int read_xenbus_vif_flags(struct backend_info *be)
vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
"feature-ipv6-csum-offload", 0);
+ read_xenbus_frontend_xdp(be, dev);
+
return 0;
}
@@ -1036,6 +1059,15 @@ static int netback_probe(struct xenbus_device *dev,
goto abort_transaction;
}
+ /* we can adjust a headroom for netfront XDP processing */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-xdp-headroom", "%d",
+ provides_xdp_headroom);
+ if (err) {
+ message = "writing feature-xdp-headroom";
+ goto abort_transaction;
+ }
+
/* We don't support rx-flip path (except old guests who
* don't grok this feature flag).
*/
--
1.8.3.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
2020-06-22 9:21 ` [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront Denis Kirjanov
@ 2020-06-22 9:58 ` Jesper Dangaard Brouer
2020-06-22 12:45 ` Denis Kirjanov
2020-06-22 12:34 ` kernel test robot
1 sibling, 1 reply; 13+ messages in thread
From: Jesper Dangaard Brouer @ 2020-06-22 9:58 UTC (permalink / raw)
To: Denis Kirjanov; +Cc: netdev, jgross, wei.liu, paul, ilias.apalodimas, brouer
On Mon, 22 Jun 2020 12:21:11 +0300 Denis Kirjanov <kda@linux-powerpc.org> wrote:
> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
> index 482c6c8..1b9f49e 100644
> --- a/drivers/net/xen-netfront.c
> +++ b/drivers/net/xen-netfront.c
[...]
> @@ -560,6 +572,65 @@ static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
> return queue_idx;
> }
>
> +static int xennet_xdp_xmit_one(struct net_device *dev, struct xdp_frame *xdpf)
> +{
> + struct netfront_info *np = netdev_priv(dev);
> + struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
> + unsigned int num_queues = dev->real_num_tx_queues;
> + struct netfront_queue *queue = NULL;
> + struct xen_netif_tx_request *tx;
> + unsigned long flags;
> + int notify;
> +
> + queue = &np->queues[smp_processor_id() % num_queues];
> +
> + spin_lock_irqsave(&queue->tx_lock, flags);
Why are you taking a lock per packet (xdp_frame)?
> +
> + tx = xennet_make_first_txreq(queue, NULL,
> + virt_to_page(xdpf->data),
> + offset_in_page(xdpf->data),
> + xdpf->len);
> +
> + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
> + if (notify)
> + notify_remote_via_irq(queue->tx_irq);
> +
> + u64_stats_update_begin(&tx_stats->syncp);
> + tx_stats->bytes += xdpf->len;
> + tx_stats->packets++;
> + u64_stats_update_end(&tx_stats->syncp);
> +
> + xennet_tx_buf_gc(queue);
> +
> + spin_unlock_irqrestore(&queue->tx_lock, flags);
Is the irqsave/irqrestore variant really needed here?
> + return 0;
> +}
> +
> +static int xennet_xdp_xmit(struct net_device *dev, int n,
> + struct xdp_frame **frames, u32 flags)
> +{
> + int drops = 0;
> + int i, err;
> +
> + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
> + return -EINVAL;
> +
> + for (i = 0; i < n; i++) {
> + struct xdp_frame *xdpf = frames[i];
> +
> + if (!xdpf)
> + continue;
> + err = xennet_xdp_xmit_one(dev, xdpf);
> + if (err) {
> + xdp_return_frame_rx_napi(xdpf);
> + drops++;
> + }
> + }
> +
> + return n - drops;
> +}
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
^ permalink raw reply [flat|nested] 13+ messages in thread
* RE: [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback
2020-06-22 9:21 ` [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback Denis Kirjanov
@ 2020-06-22 10:10 ` Paul Durrant
2020-06-22 12:50 ` Denis Kirjanov
0 siblings, 1 reply; 13+ messages in thread
From: Paul Durrant @ 2020-06-22 10:10 UTC (permalink / raw)
To: 'Denis Kirjanov', netdev
Cc: brouer, jgross, wei.liu, ilias.apalodimas
> -----Original Message-----
> From: Denis Kirjanov <kda@linux-powerpc.org>
> Sent: 22 June 2020 10:21
> To: netdev@vger.kernel.org
> Cc: brouer@redhat.com; jgross@suse.com; wei.liu@kernel.org; paul@xen.org; ilias.apalodimas@linaro.org
> Subject: [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback
>
> the patch basically adds the offset adjustment and netfront
> state reading to make XDP work on netfront side.
>
> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
> ---
> drivers/net/xen-netback/common.h | 4 ++++
> drivers/net/xen-netback/interface.c | 2 ++
> drivers/net/xen-netback/netback.c | 7 +++++++
> drivers/net/xen-netback/rx.c | 15 ++++++++++++++-
> drivers/net/xen-netback/xenbus.c | 32 ++++++++++++++++++++++++++++++++
> 5 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
> index 05847eb..f14dc10 100644
> --- a/drivers/net/xen-netback/common.h
> +++ b/drivers/net/xen-netback/common.h
> @@ -281,6 +281,9 @@ struct xenvif {
> u8 ipv6_csum:1;
> u8 multicast_control:1;
>
> + /* headroom requested by xen-netfront */
> + u16 netfront_xdp_headroom;
> +
> /* Is this interface disabled? True when backend discovers
> * frontend is rogue.
> */
> @@ -395,6 +398,7 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
> irqreturn_t xenvif_interrupt(int irq, void *dev_id);
>
> extern bool separate_tx_rx_irq;
> +extern bool provides_xdp_headroom;
>
> extern unsigned int rx_drain_timeout_msecs;
> extern unsigned int rx_stall_timeout_msecs;
> diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
> index 0c8a02a..fc16edd 100644
> --- a/drivers/net/xen-netback/interface.c
> +++ b/drivers/net/xen-netback/interface.c
> @@ -483,6 +483,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
> vif->queues = NULL;
> vif->num_queues = 0;
>
> + vif->netfront_xdp_headroom = 0;
> +
How about just 'xdp_headroom'? It's shorter to type :-)
> spin_lock_init(&vif->lock);
> INIT_LIST_HEAD(&vif->fe_mcast_addr);
>
> diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
> index 315dfc6..6dfca72 100644
> --- a/drivers/net/xen-netback/netback.c
> +++ b/drivers/net/xen-netback/netback.c
> @@ -96,6 +96,13 @@
> module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
> MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
>
> +/* The module parameter tells that we have to put data
> + * for xen-netfront with the XDP_PACKET_HEADROOM offset
> + * needed for XDP processing
> + */
> +bool provides_xdp_headroom = true;
> +module_param(provides_xdp_headroom, bool, 0644);
> +
> static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
> u8 status);
>
> diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
> index ef58870..c5e9e14 100644
> --- a/drivers/net/xen-netback/rx.c
> +++ b/drivers/net/xen-netback/rx.c
> @@ -258,6 +258,19 @@ static void xenvif_rx_next_skb(struct xenvif_queue *queue,
> pkt->extra_count++;
> }
>
> + if (queue->vif->netfront_xdp_headroom) {
> + struct xen_netif_extra_info *extra;
> +
> + extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
> +
> + memset(extra, 0, sizeof(struct xen_netif_extra_info));
> + extra->u.xdp.headroom = queue->vif->netfront_xdp_headroom;
> + extra->type = XEN_NETIF_EXTRA_TYPE_XDP;
> + extra->flags = 0;
> +
> + pkt->extra_count++;
> + }
> +
> if (skb->sw_hash) {
> struct xen_netif_extra_info *extra;
>
> @@ -356,7 +369,7 @@ static void xenvif_rx_data_slot(struct xenvif_queue *queue,
> struct xen_netif_rx_request *req,
> struct xen_netif_rx_response *rsp)
> {
> - unsigned int offset = 0;
> + unsigned int offset = queue->vif->netfront_xdp_headroom;
> unsigned int flags;
>
> do {
> diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
> index 286054b..c67abc5 100644
> --- a/drivers/net/xen-netback/xenbus.c
> +++ b/drivers/net/xen-netback/xenbus.c
> @@ -393,6 +393,22 @@ static void set_backend_state(struct backend_info *be,
> }
> }
>
> +static void read_xenbus_frontend_xdp(struct backend_info *be,
> + struct xenbus_device *dev)
> +{
> + struct xenvif *vif = be->vif;
> + u16 headroom;
> + int err;
> +
> + err = xenbus_scanf(XBT_NIL, dev->otherend,
> + "netfront-xdp-headroom", "%hu", &headroom);
Isn't it just "xdp-headroom"? That's what the comments in netif.h state.
> + if (err < 0) {
> + vif->netfront_xdp_headroom = 0;
> + return;
> + }
What is a reasonable value for maximum headroom? Do we really want to allow values all the way up to 65535?
Paul
> + vif->netfront_xdp_headroom = headroom;
> +}
> +
> /**
> * Callback received when the frontend's state changes.
> */
> @@ -417,6 +433,11 @@ static void frontend_changed(struct xenbus_device *dev,
> set_backend_state(be, XenbusStateConnected);
> break;
>
> + case XenbusStateReconfiguring:
> + read_xenbus_frontend_xdp(be, dev);
> + xenbus_switch_state(dev, XenbusStateReconfigured);
> + break;
> +
> case XenbusStateClosing:
> set_backend_state(be, XenbusStateClosing);
> break;
> @@ -947,6 +968,8 @@ static int read_xenbus_vif_flags(struct backend_info *be)
> vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
> "feature-ipv6-csum-offload", 0);
>
> + read_xenbus_frontend_xdp(be, dev);
> +
> return 0;
> }
>
> @@ -1036,6 +1059,15 @@ static int netback_probe(struct xenbus_device *dev,
> goto abort_transaction;
> }
>
> + /* we can adjust a headroom for netfront XDP processing */
> + err = xenbus_printf(xbt, dev->nodename,
> + "feature-xdp-headroom", "%d",
> + provides_xdp_headroom);
> + if (err) {
> + message = "writing feature-xdp-headroom";
> + goto abort_transaction;
> + }
> +
> /* We don't support rx-flip path (except old guests who
> * don't grok this feature flag).
> */
> --
> 1.8.3.1
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
2020-06-22 9:21 ` [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront Denis Kirjanov
@ 2020-06-22 12:34 ` kernel test robot
2020-06-22 12:34 ` kernel test robot
1 sibling, 0 replies; 13+ messages in thread
From: kernel test robot @ 2020-06-22 12:34 UTC (permalink / raw)
To: Denis Kirjanov, netdev
Cc: kbuild-all, brouer, jgross, wei.liu, paul, ilias.apalodimas
[-- Attachment #1: Type: text/plain, Size: 3472 bytes --]
Hi Denis,
I love your patch! Yet something to improve:
[auto build test ERROR on net-next/master]
url: https://github.com/0day-ci/linux/commits/Denis-Kirjanov/xen-networking-add-XDP-support-to-xen-netfront/20200622-172512
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 29a720c1042f469c8fea317cb5e7f496b116e07d
config: i386-debian-10.3 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce (this is a W=1 build):
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All error/warnings (new ones prefixed by >>):
drivers/net/xen-netfront.c: In function 'xennet_xdp_xmit_one':
drivers/net/xen-netfront.c:581:31: warning: variable 'tx' set but not used [-Wunused-but-set-variable]
581 | struct xen_netif_tx_request *tx;
| ^~
drivers/net/xen-netfront.c: In function 'xennet_run_xdp':
>> drivers/net/xen-netfront.c:871:10: error: implicit declaration of function 'convert_to_xdp_frame'; did you mean 'xdp_convert_zc_to_xdp_frame'? [-Werror=implicit-function-declaration]
871 | xdpf = convert_to_xdp_frame(xdp);
| ^~~~~~~~~~~~~~~~~~~~
| xdp_convert_zc_to_xdp_frame
>> drivers/net/xen-netfront.c:871:8: warning: assignment to 'struct xdp_frame *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
871 | xdpf = convert_to_xdp_frame(xdp);
| ^
drivers/net/xen-netfront.c: In function 'store_rxbuf':
drivers/net/xen-netfront.c:2424:16: warning: variable 'target' set but not used [-Wunused-but-set-variable]
2424 | unsigned long target;
| ^~~~~~
cc1: some warnings being treated as errors
vim +871 drivers/net/xen-netfront.c
851
852 static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
853 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
854 struct xdp_buff *xdp, bool *need_xdp_flush)
855 {
856 struct xdp_frame *xdpf;
857 u32 len = rx->status;
858 u32 act = XDP_PASS;
859 int err;
860
861 xdp->data_hard_start = page_address(pdata);
862 xdp->data = xdp->data_hard_start + XDP_PACKET_HEADROOM;
863 xdp_set_data_meta_invalid(xdp);
864 xdp->data_end = xdp->data + len;
865 xdp->rxq = &queue->xdp_rxq;
866
867 act = bpf_prog_run_xdp(prog, xdp);
868 switch (act) {
869 case XDP_TX:
870 get_page(pdata);
> 871 xdpf = convert_to_xdp_frame(xdp);
872 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
873 if (unlikely(err < 0))
874 trace_xdp_exception(queue->info->netdev, prog, act);
875 break;
876 case XDP_REDIRECT:
877 get_page(pdata);
878 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
879 *need_xdp_flush = true;
880 if (unlikely(err))
881 trace_xdp_exception(queue->info->netdev, prog, act);
882 break;
883 case XDP_PASS:
884 case XDP_DROP:
885 break;
886
887 case XDP_ABORTED:
888 trace_xdp_exception(queue->info->netdev, prog, act);
889 break;
890
891 default:
892 bpf_warn_invalid_xdp_action(act);
893 }
894
895 return act;
896 }
897
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 34808 bytes --]
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
@ 2020-06-22 12:34 ` kernel test robot
0 siblings, 0 replies; 13+ messages in thread
From: kernel test robot @ 2020-06-22 12:34 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 3564 bytes --]
Hi Denis,
I love your patch! Yet something to improve:
[auto build test ERROR on net-next/master]
url: https://github.com/0day-ci/linux/commits/Denis-Kirjanov/xen-networking-add-XDP-support-to-xen-netfront/20200622-172512
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 29a720c1042f469c8fea317cb5e7f496b116e07d
config: i386-debian-10.3 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce (this is a W=1 build):
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All error/warnings (new ones prefixed by >>):
drivers/net/xen-netfront.c: In function 'xennet_xdp_xmit_one':
drivers/net/xen-netfront.c:581:31: warning: variable 'tx' set but not used [-Wunused-but-set-variable]
581 | struct xen_netif_tx_request *tx;
| ^~
drivers/net/xen-netfront.c: In function 'xennet_run_xdp':
>> drivers/net/xen-netfront.c:871:10: error: implicit declaration of function 'convert_to_xdp_frame'; did you mean 'xdp_convert_zc_to_xdp_frame'? [-Werror=implicit-function-declaration]
871 | xdpf = convert_to_xdp_frame(xdp);
| ^~~~~~~~~~~~~~~~~~~~
| xdp_convert_zc_to_xdp_frame
>> drivers/net/xen-netfront.c:871:8: warning: assignment to 'struct xdp_frame *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
871 | xdpf = convert_to_xdp_frame(xdp);
| ^
drivers/net/xen-netfront.c: In function 'store_rxbuf':
drivers/net/xen-netfront.c:2424:16: warning: variable 'target' set but not used [-Wunused-but-set-variable]
2424 | unsigned long target;
| ^~~~~~
cc1: some warnings being treated as errors
vim +871 drivers/net/xen-netfront.c
851
852 static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
853 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
854 struct xdp_buff *xdp, bool *need_xdp_flush)
855 {
856 struct xdp_frame *xdpf;
857 u32 len = rx->status;
858 u32 act = XDP_PASS;
859 int err;
860
861 xdp->data_hard_start = page_address(pdata);
862 xdp->data = xdp->data_hard_start + XDP_PACKET_HEADROOM;
863 xdp_set_data_meta_invalid(xdp);
864 xdp->data_end = xdp->data + len;
865 xdp->rxq = &queue->xdp_rxq;
866
867 act = bpf_prog_run_xdp(prog, xdp);
868 switch (act) {
869 case XDP_TX:
870 get_page(pdata);
> 871 xdpf = convert_to_xdp_frame(xdp);
872 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
873 if (unlikely(err < 0))
874 trace_xdp_exception(queue->info->netdev, prog, act);
875 break;
876 case XDP_REDIRECT:
877 get_page(pdata);
878 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
879 *need_xdp_flush = true;
880 if (unlikely(err))
881 trace_xdp_exception(queue->info->netdev, prog, act);
882 break;
883 case XDP_PASS:
884 case XDP_DROP:
885 break;
886
887 case XDP_ABORTED:
888 trace_xdp_exception(queue->info->netdev, prog, act);
889 break;
890
891 default:
892 bpf_warn_invalid_xdp_action(act);
893 }
894
895 return act;
896 }
897
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 34808 bytes --]
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
2020-06-22 9:58 ` Jesper Dangaard Brouer
@ 2020-06-22 12:45 ` Denis Kirjanov
2020-06-22 13:28 ` Jesper Dangaard Brouer
0 siblings, 1 reply; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 12:45 UTC (permalink / raw)
To: Jesper Dangaard Brouer; +Cc: netdev, jgross, wei.liu, paul, ilias.apalodimas
On 6/22/20, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
>
> On Mon, 22 Jun 2020 12:21:11 +0300 Denis Kirjanov <kda@linux-powerpc.org>
> wrote:
>
>> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
>> index 482c6c8..1b9f49e 100644
>> --- a/drivers/net/xen-netfront.c
>> +++ b/drivers/net/xen-netfront.c
> [...]
>> @@ -560,6 +572,65 @@ static u16 xennet_select_queue(struct net_device
>> *dev, struct sk_buff *skb,
>> return queue_idx;
>> }
>>
>> +static int xennet_xdp_xmit_one(struct net_device *dev, struct xdp_frame
>> *xdpf)
>> +{
>> + struct netfront_info *np = netdev_priv(dev);
>> + struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
>> + unsigned int num_queues = dev->real_num_tx_queues;
>> + struct netfront_queue *queue = NULL;
>> + struct xen_netif_tx_request *tx;
>> + unsigned long flags;
>> + int notify;
>> +
>> + queue = &np->queues[smp_processor_id() % num_queues];
>> +
>> + spin_lock_irqsave(&queue->tx_lock, flags);
>
> Why are you taking a lock per packet (xdp_frame)?
Hi Jesper,
We have to protect shared ring indices.
>
>> +
>> + tx = xennet_make_first_txreq(queue, NULL,
>> + virt_to_page(xdpf->data),
>> + offset_in_page(xdpf->data),
>> + xdpf->len);
>> +
>> + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
>> + if (notify)
>> + notify_remote_via_irq(queue->tx_irq);
>> +
>> + u64_stats_update_begin(&tx_stats->syncp);
>> + tx_stats->bytes += xdpf->len;
>> + tx_stats->packets++;
>> + u64_stats_update_end(&tx_stats->syncp);
>> +
>> + xennet_tx_buf_gc(queue);
>> +
>> + spin_unlock_irqrestore(&queue->tx_lock, flags);
>
> Is the irqsave/irqrestore variant really needed here?
netpoll also invokes the tx completion handler.
>
>> + return 0;
>> +}
>> +
>> +static int xennet_xdp_xmit(struct net_device *dev, int n,
>> + struct xdp_frame **frames, u32 flags)
>> +{
>> + int drops = 0;
>> + int i, err;
>> +
>> + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
>> + return -EINVAL;
>> +
>> + for (i = 0; i < n; i++) {
>> + struct xdp_frame *xdpf = frames[i];
>> +
>> + if (!xdpf)
>> + continue;
>> + err = xennet_xdp_xmit_one(dev, xdpf);
>> + if (err) {
>> + xdp_return_frame_rx_napi(xdpf);
>> + drops++;
>> + }
>> + }
>> +
>> + return n - drops;
>> +}
>
>
>
> --
> Best regards,
> Jesper Dangaard Brouer
> MSc.CS, Principal Kernel Engineer at Red Hat
> LinkedIn: http://www.linkedin.com/in/brouer
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback
2020-06-22 10:10 ` Paul Durrant
@ 2020-06-22 12:50 ` Denis Kirjanov
2020-06-22 14:56 ` Paul Durrant
0 siblings, 1 reply; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 12:50 UTC (permalink / raw)
To: paul; +Cc: netdev, brouer, jgross, wei.liu, ilias.apalodimas
On 6/22/20, Paul Durrant <xadimgnik@gmail.com> wrote:
>> -----Original Message-----
>> From: Denis Kirjanov <kda@linux-powerpc.org>
>> Sent: 22 June 2020 10:21
>> To: netdev@vger.kernel.org
>> Cc: brouer@redhat.com; jgross@suse.com; wei.liu@kernel.org; paul@xen.org;
>> ilias.apalodimas@linaro.org
>> Subject: [PATCH net-next v10 3/3] xen networking: add XDP offset
>> adjustment to xen-netback
>>
>> the patch basically adds the offset adjustment and netfront
>> state reading to make XDP work on netfront side.
>>
>> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
>> ---
>> drivers/net/xen-netback/common.h | 4 ++++
>> drivers/net/xen-netback/interface.c | 2 ++
>> drivers/net/xen-netback/netback.c | 7 +++++++
>> drivers/net/xen-netback/rx.c | 15 ++++++++++++++-
>> drivers/net/xen-netback/xenbus.c | 32
>> ++++++++++++++++++++++++++++++++
>> 5 files changed, 59 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/xen-netback/common.h
>> b/drivers/net/xen-netback/common.h
>> index 05847eb..f14dc10 100644
>> --- a/drivers/net/xen-netback/common.h
>> +++ b/drivers/net/xen-netback/common.h
>> @@ -281,6 +281,9 @@ struct xenvif {
>> u8 ipv6_csum:1;
>> u8 multicast_control:1;
>>
>> + /* headroom requested by xen-netfront */
>> + u16 netfront_xdp_headroom;
>> +
>> /* Is this interface disabled? True when backend discovers
>> * frontend is rogue.
>> */
>> @@ -395,6 +398,7 @@ static inline pending_ring_idx_t
>> nr_pending_reqs(struct xenvif_queue *queue)
>> irqreturn_t xenvif_interrupt(int irq, void *dev_id);
>>
>> extern bool separate_tx_rx_irq;
>> +extern bool provides_xdp_headroom;
>>
>> extern unsigned int rx_drain_timeout_msecs;
>> extern unsigned int rx_stall_timeout_msecs;
>> diff --git a/drivers/net/xen-netback/interface.c
>> b/drivers/net/xen-netback/interface.c
>> index 0c8a02a..fc16edd 100644
>> --- a/drivers/net/xen-netback/interface.c
>> +++ b/drivers/net/xen-netback/interface.c
>> @@ -483,6 +483,8 @@ struct xenvif *xenvif_alloc(struct device *parent,
>> domid_t domid,
>> vif->queues = NULL;
>> vif->num_queues = 0;
>>
>> + vif->netfront_xdp_headroom = 0;
>> +
>
Hi Paul,
> How about just 'xdp_headroom'? It's shorter to type :-)
makes sense.
>
>> spin_lock_init(&vif->lock);
>> INIT_LIST_HEAD(&vif->fe_mcast_addr);
>>
>> diff --git a/drivers/net/xen-netback/netback.c
>> b/drivers/net/xen-netback/netback.c
>> index 315dfc6..6dfca72 100644
>> --- a/drivers/net/xen-netback/netback.c
>> +++ b/drivers/net/xen-netback/netback.c
>> @@ -96,6 +96,13 @@
>> module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
>> MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
>>
>> +/* The module parameter tells that we have to put data
>> + * for xen-netfront with the XDP_PACKET_HEADROOM offset
>> + * needed for XDP processing
>> + */
>> +bool provides_xdp_headroom = true;
>> +module_param(provides_xdp_headroom, bool, 0644);
>> +
>> static void xenvif_idx_release(struct xenvif_queue *queue, u16
>> pending_idx,
>> u8 status);
>>
>> diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
>> index ef58870..c5e9e14 100644
>> --- a/drivers/net/xen-netback/rx.c
>> +++ b/drivers/net/xen-netback/rx.c
>> @@ -258,6 +258,19 @@ static void xenvif_rx_next_skb(struct xenvif_queue
>> *queue,
>> pkt->extra_count++;
>> }
>>
>> + if (queue->vif->netfront_xdp_headroom) {
>> + struct xen_netif_extra_info *extra;
>> +
>> + extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
>> +
>> + memset(extra, 0, sizeof(struct xen_netif_extra_info));
>> + extra->u.xdp.headroom = queue->vif->netfront_xdp_headroom;
>> + extra->type = XEN_NETIF_EXTRA_TYPE_XDP;
>> + extra->flags = 0;
>> +
>> + pkt->extra_count++;
>> + }
>> +
>> if (skb->sw_hash) {
>> struct xen_netif_extra_info *extra;
>>
>> @@ -356,7 +369,7 @@ static void xenvif_rx_data_slot(struct xenvif_queue
>> *queue,
>> struct xen_netif_rx_request *req,
>> struct xen_netif_rx_response *rsp)
>> {
>> - unsigned int offset = 0;
>> + unsigned int offset = queue->vif->netfront_xdp_headroom;
>> unsigned int flags;
>>
>> do {
>> diff --git a/drivers/net/xen-netback/xenbus.c
>> b/drivers/net/xen-netback/xenbus.c
>> index 286054b..c67abc5 100644
>> --- a/drivers/net/xen-netback/xenbus.c
>> +++ b/drivers/net/xen-netback/xenbus.c
>> @@ -393,6 +393,22 @@ static void set_backend_state(struct backend_info
>> *be,
>> }
>> }
>>
>> +static void read_xenbus_frontend_xdp(struct backend_info *be,
>> + struct xenbus_device *dev)
>> +{
>> + struct xenvif *vif = be->vif;
>> + u16 headroom;
>> + int err;
>> +
>> + err = xenbus_scanf(XBT_NIL, dev->otherend,
>> + "netfront-xdp-headroom", "%hu", &headroom);
>
> Isn't it just "xdp-headroom"? That's what the comments in netif.h state.
>
>> + if (err < 0) {
>> + vif->netfront_xdp_headroom = 0;
>> + return;
>> + }
>
> What is a reasonable value for maximum headroom? Do we really want to allow
> values all the way up to 65535?
Since the headroom is used for encapsulation I think we definitely
don't need more than 65535
but more that 255
>
> Paul
>
>> + vif->netfront_xdp_headroom = headroom;
>> +}
>> +
>> /**
>> * Callback received when the frontend's state changes.
>> */
>> @@ -417,6 +433,11 @@ static void frontend_changed(struct xenbus_device
>> *dev,
>> set_backend_state(be, XenbusStateConnected);
>> break;
>>
>> + case XenbusStateReconfiguring:
>> + read_xenbus_frontend_xdp(be, dev);
>> + xenbus_switch_state(dev, XenbusStateReconfigured);
>> + break;
>> +
>> case XenbusStateClosing:
>> set_backend_state(be, XenbusStateClosing);
>> break;
>> @@ -947,6 +968,8 @@ static int read_xenbus_vif_flags(struct backend_info
>> *be)
>> vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
>> "feature-ipv6-csum-offload", 0);
>>
>> + read_xenbus_frontend_xdp(be, dev);
>> +
>> return 0;
>> }
>>
>> @@ -1036,6 +1059,15 @@ static int netback_probe(struct xenbus_device
>> *dev,
>> goto abort_transaction;
>> }
>>
>> + /* we can adjust a headroom for netfront XDP processing */
>> + err = xenbus_printf(xbt, dev->nodename,
>> + "feature-xdp-headroom", "%d",
>> + provides_xdp_headroom);
>> + if (err) {
>> + message = "writing feature-xdp-headroom";
>> + goto abort_transaction;
>> + }
>> +
>> /* We don't support rx-flip path (except old guests who
>> * don't grok this feature flag).
>> */
>> --
>> 1.8.3.1
>
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
2020-06-22 12:45 ` Denis Kirjanov
@ 2020-06-22 13:28 ` Jesper Dangaard Brouer
2020-06-22 14:27 ` Denis Kirjanov
0 siblings, 1 reply; 13+ messages in thread
From: Jesper Dangaard Brouer @ 2020-06-22 13:28 UTC (permalink / raw)
To: Denis Kirjanov; +Cc: netdev, jgross, wei.liu, paul, ilias.apalodimas, brouer
On Mon, 22 Jun 2020 15:45:46 +0300
Denis Kirjanov <kda@linux-powerpc.org> wrote:
> On 6/22/20, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
> >
> > On Mon, 22 Jun 2020 12:21:11 +0300 Denis Kirjanov <kda@linux-powerpc.org>
> > wrote:
> >
> >> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
> >> index 482c6c8..1b9f49e 100644
> >> --- a/drivers/net/xen-netfront.c
> >> +++ b/drivers/net/xen-netfront.c
> > [...]
> >> @@ -560,6 +572,65 @@ static u16 xennet_select_queue(struct net_device
> >> *dev, struct sk_buff *skb,
> >> return queue_idx;
> >> }
> >>
> >> +static int xennet_xdp_xmit_one(struct net_device *dev, struct xdp_frame
> >> *xdpf)
> >> +{
> >> + struct netfront_info *np = netdev_priv(dev);
> >> + struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
> >> + unsigned int num_queues = dev->real_num_tx_queues;
> >> + struct netfront_queue *queue = NULL;
> >> + struct xen_netif_tx_request *tx;
> >> + unsigned long flags;
> >> + int notify;
> >> +
> >> + queue = &np->queues[smp_processor_id() % num_queues];
> >> +
> >> + spin_lock_irqsave(&queue->tx_lock, flags);
> >
> > Why are you taking a lock per packet (xdp_frame)?
> Hi Jesper,
>
> We have to protect shared ring indices.
Sure, I understand we need to protect the rings.
What I'm asking is why are doing this per-packet, and not once for the
entire bulk of packets?
(notice how xennet_xdp_xmit gets a bulk of packets)
> >
> >> +
> >> + tx = xennet_make_first_txreq(queue, NULL,
> >> + virt_to_page(xdpf->data),
> >> + offset_in_page(xdpf->data),
> >> + xdpf->len);
> >> +
> >> + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
> >> + if (notify)
> >> + notify_remote_via_irq(queue->tx_irq);
> >> +
> >> + u64_stats_update_begin(&tx_stats->syncp);
> >> + tx_stats->bytes += xdpf->len;
> >> + tx_stats->packets++;
> >> + u64_stats_update_end(&tx_stats->syncp);
> >> +
> >> + xennet_tx_buf_gc(queue);
> >> +
> >> + spin_unlock_irqrestore(&queue->tx_lock, flags);
> >
> > Is the irqsave/irqrestore variant really needed here?
>
> netpoll also invokes the tx completion handler.
I forgot about netpoll.
The netpoll code cannot call this code path xennet_xdp_xmit /
xennet_xdp_xmit_one, right?
Are the per-CPU ring queue's shared with normal network stack, that can
be called from netpoll code path?
queue = &np->queues[smp_processor_id() % num_queues];
> >
> >> + return 0;
> >> +}
> >> +
> >> +static int xennet_xdp_xmit(struct net_device *dev, int n,
> >> + struct xdp_frame **frames, u32 flags)
> >> +{
> >> + int drops = 0;
> >> + int i, err;
> >> +
> >> + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
> >> + return -EINVAL;
> >> +
> >> + for (i = 0; i < n; i++) {
> >> + struct xdp_frame *xdpf = frames[i];
> >> +
> >> + if (!xdpf)
> >> + continue;
> >> + err = xennet_xdp_xmit_one(dev, xdpf);
> >> + if (err) {
> >> + xdp_return_frame_rx_napi(xdpf);
> >> + drops++;
> >> + }
> >> + }
> >> +
> >> + return n - drops;
> >> +}
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront
2020-06-22 13:28 ` Jesper Dangaard Brouer
@ 2020-06-22 14:27 ` Denis Kirjanov
0 siblings, 0 replies; 13+ messages in thread
From: Denis Kirjanov @ 2020-06-22 14:27 UTC (permalink / raw)
To: Jesper Dangaard Brouer; +Cc: netdev, jgross, wei.liu, paul, ilias.apalodimas
On 6/22/20, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
> On Mon, 22 Jun 2020 15:45:46 +0300
> Denis Kirjanov <kda@linux-powerpc.org> wrote:
>
>> On 6/22/20, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
>> >
>> > On Mon, 22 Jun 2020 12:21:11 +0300 Denis Kirjanov
>> > <kda@linux-powerpc.org>
>> > wrote:
>> >
>> >> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
>> >> index 482c6c8..1b9f49e 100644
>> >> --- a/drivers/net/xen-netfront.c
>> >> +++ b/drivers/net/xen-netfront.c
>> > [...]
>> >> @@ -560,6 +572,65 @@ static u16 xennet_select_queue(struct net_device
>> >> *dev, struct sk_buff *skb,
>> >> return queue_idx;
>> >> }
>> >>
>> >> +static int xennet_xdp_xmit_one(struct net_device *dev, struct
>> >> xdp_frame
>> >> *xdpf)
>> >> +{
>> >> + struct netfront_info *np = netdev_priv(dev);
>> >> + struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
>> >> + unsigned int num_queues = dev->real_num_tx_queues;
>> >> + struct netfront_queue *queue = NULL;
>> >> + struct xen_netif_tx_request *tx;
>> >> + unsigned long flags;
>> >> + int notify;
>> >> +
>> >> + queue = &np->queues[smp_processor_id() % num_queues];
>> >> +
>> >> + spin_lock_irqsave(&queue->tx_lock, flags);
>> >
>> > Why are you taking a lock per packet (xdp_frame)?
>> Hi Jesper,
>>
>> We have to protect shared ring indices.
>
> Sure, I understand we need to protect the rings.
>
> What I'm asking is why are doing this per-packet, and not once for the
> entire bulk of packets?
Now I see. I believe we can. Do you think it will give performance
from the cache perspective?
>
> (notice how xennet_xdp_xmit gets a bulk of packets)
>
>> >
>> >> +
>> >> + tx = xennet_make_first_txreq(queue, NULL,
>> >> + virt_to_page(xdpf->data),
>> >> + offset_in_page(xdpf->data),
>> >> + xdpf->len);
>> >> +
>> >> + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
>> >> + if (notify)
>> >> + notify_remote_via_irq(queue->tx_irq);
>> >> +
>> >> + u64_stats_update_begin(&tx_stats->syncp);
>> >> + tx_stats->bytes += xdpf->len;
>> >> + tx_stats->packets++;
>> >> + u64_stats_update_end(&tx_stats->syncp);
>> >> +
>> >> + xennet_tx_buf_gc(queue);
>> >> +
>> >> + spin_unlock_irqrestore(&queue->tx_lock, flags);
>> >
>> > Is the irqsave/irqrestore variant really needed here?
>>
>> netpoll also invokes the tx completion handler.
>
> I forgot about netpoll.
>
> The netpoll code cannot call this code path xennet_xdp_xmit /
> xennet_xdp_xmit_one, right?
>
> Are the per-CPU ring queue's shared with normal network stack, that can
> be called from netpoll code path?
I meant that both xennet_start_xmit and xennet_poll_controller call
xennet_tx_buf_gc
>
> queue = &np->queues[smp_processor_id() % num_queues];
>
>
>> >
>> >> + return 0;
>> >> +}
>> >> +
>> >> +static int xennet_xdp_xmit(struct net_device *dev, int n,
>> >> + struct xdp_frame **frames, u32 flags)
>> >> +{
>> >> + int drops = 0;
>> >> + int i, err;
>> >> +
>> >> + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
>> >> + return -EINVAL;
>> >> +
>> >> + for (i = 0; i < n; i++) {
>> >> + struct xdp_frame *xdpf = frames[i];
>> >> +
>> >> + if (!xdpf)
>> >> + continue;
>> >> + err = xennet_xdp_xmit_one(dev, xdpf);
>> >> + if (err) {
>> >> + xdp_return_frame_rx_napi(xdpf);
>> >> + drops++;
>> >> + }
>> >> + }
>> >> +
>> >> + return n - drops;
>> >> +}
>
> --
> Best regards,
> Jesper Dangaard Brouer
> MSc.CS, Principal Kernel Engineer at Red Hat
> LinkedIn: http://www.linkedin.com/in/brouer
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* RE: [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback
2020-06-22 12:50 ` Denis Kirjanov
@ 2020-06-22 14:56 ` Paul Durrant
0 siblings, 0 replies; 13+ messages in thread
From: Paul Durrant @ 2020-06-22 14:56 UTC (permalink / raw)
To: 'Denis Kirjanov'
Cc: netdev, brouer, jgross, wei.liu, ilias.apalodimas
> -----Original Message-----
> From: Denis Kirjanov <kda@linux-powerpc.org>
> Sent: 22 June 2020 13:51
> To: paul@xen.org
> Cc: netdev@vger.kernel.org; brouer@redhat.com; jgross@suse.com; wei.liu@kernel.org;
> ilias.apalodimas@linaro.org
> Subject: Re: [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback
>
> On 6/22/20, Paul Durrant <xadimgnik@gmail.com> wrote:
> >> -----Original Message-----
> >> From: Denis Kirjanov <kda@linux-powerpc.org>
> >> Sent: 22 June 2020 10:21
> >> To: netdev@vger.kernel.org
> >> Cc: brouer@redhat.com; jgross@suse.com; wei.liu@kernel.org; paul@xen.org;
> >> ilias.apalodimas@linaro.org
> >> Subject: [PATCH net-next v10 3/3] xen networking: add XDP offset
> >> adjustment to xen-netback
> >>
> >> the patch basically adds the offset adjustment and netfront
> >> state reading to make XDP work on netfront side.
> >>
> >> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
> >> ---
> >> drivers/net/xen-netback/common.h | 4 ++++
> >> drivers/net/xen-netback/interface.c | 2 ++
> >> drivers/net/xen-netback/netback.c | 7 +++++++
> >> drivers/net/xen-netback/rx.c | 15 ++++++++++++++-
> >> drivers/net/xen-netback/xenbus.c | 32
> >> ++++++++++++++++++++++++++++++++
> >> 5 files changed, 59 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/xen-netback/common.h
> >> b/drivers/net/xen-netback/common.h
> >> index 05847eb..f14dc10 100644
> >> --- a/drivers/net/xen-netback/common.h
> >> +++ b/drivers/net/xen-netback/common.h
> >> @@ -281,6 +281,9 @@ struct xenvif {
> >> u8 ipv6_csum:1;
> >> u8 multicast_control:1;
> >>
> >> + /* headroom requested by xen-netfront */
> >> + u16 netfront_xdp_headroom;
> >> +
> >> /* Is this interface disabled? True when backend discovers
> >> * frontend is rogue.
> >> */
> >> @@ -395,6 +398,7 @@ static inline pending_ring_idx_t
> >> nr_pending_reqs(struct xenvif_queue *queue)
> >> irqreturn_t xenvif_interrupt(int irq, void *dev_id);
> >>
> >> extern bool separate_tx_rx_irq;
> >> +extern bool provides_xdp_headroom;
> >>
> >> extern unsigned int rx_drain_timeout_msecs;
> >> extern unsigned int rx_stall_timeout_msecs;
> >> diff --git a/drivers/net/xen-netback/interface.c
> >> b/drivers/net/xen-netback/interface.c
> >> index 0c8a02a..fc16edd 100644
> >> --- a/drivers/net/xen-netback/interface.c
> >> +++ b/drivers/net/xen-netback/interface.c
> >> @@ -483,6 +483,8 @@ struct xenvif *xenvif_alloc(struct device *parent,
> >> domid_t domid,
> >> vif->queues = NULL;
> >> vif->num_queues = 0;
> >>
> >> + vif->netfront_xdp_headroom = 0;
> >> +
> >
> Hi Paul,
>
> > How about just 'xdp_headroom'? It's shorter to type :-)
>
> makes sense.
>
> >
> >> spin_lock_init(&vif->lock);
> >> INIT_LIST_HEAD(&vif->fe_mcast_addr);
> >>
> >> diff --git a/drivers/net/xen-netback/netback.c
> >> b/drivers/net/xen-netback/netback.c
> >> index 315dfc6..6dfca72 100644
> >> --- a/drivers/net/xen-netback/netback.c
> >> +++ b/drivers/net/xen-netback/netback.c
> >> @@ -96,6 +96,13 @@
> >> module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
> >> MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
> >>
> >> +/* The module parameter tells that we have to put data
> >> + * for xen-netfront with the XDP_PACKET_HEADROOM offset
> >> + * needed for XDP processing
> >> + */
> >> +bool provides_xdp_headroom = true;
> >> +module_param(provides_xdp_headroom, bool, 0644);
> >> +
> >> static void xenvif_idx_release(struct xenvif_queue *queue, u16
> >> pending_idx,
> >> u8 status);
> >>
> >> diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
> >> index ef58870..c5e9e14 100644
> >> --- a/drivers/net/xen-netback/rx.c
> >> +++ b/drivers/net/xen-netback/rx.c
> >> @@ -258,6 +258,19 @@ static void xenvif_rx_next_skb(struct xenvif_queue
> >> *queue,
> >> pkt->extra_count++;
> >> }
> >>
> >> + if (queue->vif->netfront_xdp_headroom) {
> >> + struct xen_netif_extra_info *extra;
> >> +
> >> + extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
> >> +
> >> + memset(extra, 0, sizeof(struct xen_netif_extra_info));
> >> + extra->u.xdp.headroom = queue->vif->netfront_xdp_headroom;
> >> + extra->type = XEN_NETIF_EXTRA_TYPE_XDP;
> >> + extra->flags = 0;
> >> +
> >> + pkt->extra_count++;
> >> + }
> >> +
> >> if (skb->sw_hash) {
> >> struct xen_netif_extra_info *extra;
> >>
> >> @@ -356,7 +369,7 @@ static void xenvif_rx_data_slot(struct xenvif_queue
> >> *queue,
> >> struct xen_netif_rx_request *req,
> >> struct xen_netif_rx_response *rsp)
> >> {
> >> - unsigned int offset = 0;
> >> + unsigned int offset = queue->vif->netfront_xdp_headroom;
> >> unsigned int flags;
> >>
> >> do {
> >> diff --git a/drivers/net/xen-netback/xenbus.c
> >> b/drivers/net/xen-netback/xenbus.c
> >> index 286054b..c67abc5 100644
> >> --- a/drivers/net/xen-netback/xenbus.c
> >> +++ b/drivers/net/xen-netback/xenbus.c
> >> @@ -393,6 +393,22 @@ static void set_backend_state(struct backend_info
> >> *be,
> >> }
> >> }
> >>
> >> +static void read_xenbus_frontend_xdp(struct backend_info *be,
> >> + struct xenbus_device *dev)
> >> +{
> >> + struct xenvif *vif = be->vif;
> >> + u16 headroom;
> >> + int err;
> >> +
> >> + err = xenbus_scanf(XBT_NIL, dev->otherend,
> >> + "netfront-xdp-headroom", "%hu", &headroom);
> >
> > Isn't it just "xdp-headroom"? That's what the comments in netif.h state.
> >
> >> + if (err < 0) {
> >> + vif->netfront_xdp_headroom = 0;
> >> + return;
> >> + }
> >
> > What is a reasonable value for maximum headroom? Do we really want to allow
> > values all the way up to 65535?
>
> Since the headroom is used for encapsulation I think we definitely
> don't need more than 65535
> but more that 255
Ok, I suggest documenting (and defining) the max in netif.h then and then sanity checking it here. Also I just noticed that your check on xenbus_scanf's return value is not correct since its return semantics are the same as for normal scanf(3).
Paul
>
>
> >
> > Paul
> >
> >> + vif->netfront_xdp_headroom = headroom;
> >> +}
> >> +
> >> /**
> >> * Callback received when the frontend's state changes.
> >> */
> >> @@ -417,6 +433,11 @@ static void frontend_changed(struct xenbus_device
> >> *dev,
> >> set_backend_state(be, XenbusStateConnected);
> >> break;
> >>
> >> + case XenbusStateReconfiguring:
> >> + read_xenbus_frontend_xdp(be, dev);
> >> + xenbus_switch_state(dev, XenbusStateReconfigured);
> >> + break;
> >> +
> >> case XenbusStateClosing:
> >> set_backend_state(be, XenbusStateClosing);
> >> break;
> >> @@ -947,6 +968,8 @@ static int read_xenbus_vif_flags(struct backend_info
> >> *be)
> >> vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
> >> "feature-ipv6-csum-offload", 0);
> >>
> >> + read_xenbus_frontend_xdp(be, dev);
> >> +
> >> return 0;
> >> }
> >>
> >> @@ -1036,6 +1059,15 @@ static int netback_probe(struct xenbus_device
> >> *dev,
> >> goto abort_transaction;
> >> }
> >>
> >> + /* we can adjust a headroom for netfront XDP processing */
> >> + err = xenbus_printf(xbt, dev->nodename,
> >> + "feature-xdp-headroom", "%d",
> >> + provides_xdp_headroom);
> >> + if (err) {
> >> + message = "writing feature-xdp-headroom";
> >> + goto abort_transaction;
> >> + }
> >> +
> >> /* We don't support rx-flip path (except old guests who
> >> * don't grok this feature flag).
> >> */
> >> --
> >> 1.8.3.1
> >
> >
> >
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2020-06-22 14:56 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-22 9:21 [PATCH net-next v10 0/3] xen networking: add XDP support to xen-netfront Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 1/3] xen: netif.h: add a new extra type for XDP Denis Kirjanov
2020-06-22 9:21 ` [PATCH net-next v10 2/3] xen networking: add basic XDP support for xen-netfront Denis Kirjanov
2020-06-22 9:58 ` Jesper Dangaard Brouer
2020-06-22 12:45 ` Denis Kirjanov
2020-06-22 13:28 ` Jesper Dangaard Brouer
2020-06-22 14:27 ` Denis Kirjanov
2020-06-22 12:34 ` kernel test robot
2020-06-22 12:34 ` kernel test robot
2020-06-22 9:21 ` [PATCH net-next v10 3/3] xen networking: add XDP offset adjustment to xen-netback Denis Kirjanov
2020-06-22 10:10 ` Paul Durrant
2020-06-22 12:50 ` Denis Kirjanov
2020-06-22 14:56 ` Paul Durrant
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