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-rw-r--r--drivers/net/xen-netback/common.h5
-rw-r--r--drivers/net/xen-netback/interface.c62
-rw-r--r--drivers/net/xen-netback/netback.c36
-rw-r--r--drivers/net/xen-netback/xenbus.c17
4 files changed, 66 insertions, 54 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index ef3026f46a3..d4eb8d2e9cb 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -165,6 +165,7 @@ struct xenvif_queue { /* Per-queue data for xenvif */
u16 dealloc_ring[MAX_PENDING_REQS];
struct task_struct *dealloc_task;
wait_queue_head_t dealloc_wq;
+ atomic_t inflight_packets;
/* Use kthread for guest RX */
struct task_struct *task;
@@ -329,4 +330,8 @@ extern unsigned int xenvif_max_queues;
extern struct dentry *xen_netback_dbg_root;
#endif
+void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
+ struct sk_buff *skb);
+void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
+
#endif /* __XEN_NETBACK__COMMON_H__ */
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 48a55cda979..e29e15dca86 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -43,6 +43,23 @@
#define XENVIF_QUEUE_LENGTH 32
#define XENVIF_NAPI_WEIGHT 64
+/* This function is used to set SKBTX_DEV_ZEROCOPY as well as
+ * increasing the inflight counter. We need to increase the inflight
+ * counter because core driver calls into xenvif_zerocopy_callback
+ * which calls xenvif_skb_zerocopy_complete.
+ */
+void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
+ struct sk_buff *skb)
+{
+ skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ atomic_inc(&queue->inflight_packets);
+}
+
+void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
+{
+ atomic_dec(&queue->inflight_packets);
+}
+
static inline void xenvif_stop_queue(struct xenvif_queue *queue)
{
struct net_device *dev = queue->vif->dev;
@@ -78,12 +95,8 @@ int xenvif_poll(struct napi_struct *napi, int budget)
/* This vif is rogue, we pretend we've there is nothing to do
* for this vif to deschedule it from NAPI. But this interface
* will be turned off in thread context later.
- * Also, if a guest doesn't post enough slots to receive data on one of
- * its queues, the carrier goes down and NAPI is descheduled here so
- * the guest can't send more packets until it's ready to receive.
*/
- if (unlikely(queue->vif->disabled ||
- !netif_carrier_ok(queue->vif->dev))) {
+ if (unlikely(queue->vif->disabled)) {
napi_complete(napi);
return 0;
}
@@ -528,9 +541,6 @@ int xenvif_init_queue(struct xenvif_queue *queue)
init_timer(&queue->rx_stalled);
- netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
- XENVIF_NAPI_WEIGHT);
-
return 0;
}
@@ -564,6 +574,7 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
init_waitqueue_head(&queue->wq);
init_waitqueue_head(&queue->dealloc_wq);
+ atomic_set(&queue->inflight_packets, 0);
if (tx_evtchn == rx_evtchn) {
/* feature-split-event-channels == 0 */
@@ -618,6 +629,9 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
wake_up_process(queue->task);
wake_up_process(queue->dealloc_task);
+ netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
+ XENVIF_NAPI_WEIGHT);
+
return 0;
err_rx_unbind:
@@ -646,25 +660,6 @@ void xenvif_carrier_off(struct xenvif *vif)
rtnl_unlock();
}
-static void xenvif_wait_unmap_timeout(struct xenvif_queue *queue,
- unsigned int worst_case_skb_lifetime)
-{
- int i, unmap_timeout = 0;
-
- for (i = 0; i < MAX_PENDING_REQS; ++i) {
- if (queue->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) {
- unmap_timeout++;
- schedule_timeout(msecs_to_jiffies(1000));
- if (unmap_timeout > worst_case_skb_lifetime &&
- net_ratelimit())
- netdev_err(queue->vif->dev,
- "Page still granted! Index: %x\n",
- i);
- i = -1;
- }
- }
-}
-
void xenvif_disconnect(struct xenvif *vif)
{
struct xenvif_queue *queue = NULL;
@@ -676,6 +671,8 @@ void xenvif_disconnect(struct xenvif *vif)
for (queue_index = 0; queue_index < num_queues; ++queue_index) {
queue = &vif->queues[queue_index];
+ netif_napi_del(&queue->napi);
+
if (queue->task) {
del_timer_sync(&queue->rx_stalled);
kthread_stop(queue->task);
@@ -708,7 +705,6 @@ void xenvif_disconnect(struct xenvif *vif)
void xenvif_deinit_queue(struct xenvif_queue *queue)
{
free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages);
- netif_napi_del(&queue->napi);
}
void xenvif_free(struct xenvif *vif)
@@ -716,21 +712,11 @@ void xenvif_free(struct xenvif *vif)
struct xenvif_queue *queue = NULL;
unsigned int num_queues = vif->num_queues;
unsigned int queue_index;
- /* Here we want to avoid timeout messages if an skb can be legitimately
- * stuck somewhere else. Realistically this could be an another vif's
- * internal or QDisc queue. That another vif also has this
- * rx_drain_timeout_msecs timeout, so give it time to drain out.
- * Although if that other guest wakes up just before its timeout happens
- * and takes only one skb from QDisc, it can hold onto other skbs for a
- * longer period.
- */
- unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000);
unregister_netdev(vif->dev);
for (queue_index = 0; queue_index < num_queues; ++queue_index) {
queue = &vif->queues[queue_index];
- xenvif_wait_unmap_timeout(queue, worst_case_skb_lifetime);
xenvif_deinit_queue(queue);
}
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index aa2093325be..08f65996534 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1525,10 +1525,12 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s
/* remove traces of mapped pages and frag_list */
skb_frag_list_init(skb);
uarg = skb_shinfo(skb)->destructor_arg;
+ /* increase inflight counter to offset decrement in callback */
+ atomic_inc(&queue->inflight_packets);
uarg->callback(uarg, true);
skb_shinfo(skb)->destructor_arg = NULL;
- skb_shinfo(nskb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ xenvif_skb_zerocopy_prepare(queue, nskb);
kfree_skb(nskb);
return 0;
@@ -1589,7 +1591,7 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
if (net_ratelimit())
netdev_err(queue->vif->dev,
"Not enough memory to consolidate frag_list!\n");
- skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ xenvif_skb_zerocopy_prepare(queue, skb);
kfree_skb(skb);
continue;
}
@@ -1609,7 +1611,7 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
"Can't setup checksum in net_tx_action\n");
/* We have to set this flag to trigger the callback */
if (skb_shinfo(skb)->destructor_arg)
- skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ xenvif_skb_zerocopy_prepare(queue, skb);
kfree_skb(skb);
continue;
}
@@ -1641,7 +1643,7 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
* skb. E.g. the __pskb_pull_tail earlier can do such thing.
*/
if (skb_shinfo(skb)->destructor_arg) {
- skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ xenvif_skb_zerocopy_prepare(queue, skb);
queue->stats.tx_zerocopy_sent++;
}
@@ -1681,6 +1683,7 @@ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
queue->stats.tx_zerocopy_success++;
else
queue->stats.tx_zerocopy_fail++;
+ xenvif_skb_zerocopy_complete(queue);
}
static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
@@ -2025,9 +2028,15 @@ int xenvif_kthread_guest_rx(void *data)
* context so we defer it here, if this thread is
* associated with queue 0.
*/
- if (unlikely(queue->vif->disabled && queue->id == 0))
+ if (unlikely(queue->vif->disabled && queue->id == 0)) {
xenvif_carrier_off(queue->vif);
- else if (unlikely(test_and_clear_bit(QUEUE_STATUS_RX_PURGE_EVENT,
+ } else if (unlikely(queue->vif->disabled)) {
+ /* kthread_stop() would be called upon this thread soon,
+ * be a bit proactive
+ */
+ skb_queue_purge(&queue->rx_queue);
+ queue->rx_last_skb_slots = 0;
+ } else if (unlikely(test_and_clear_bit(QUEUE_STATUS_RX_PURGE_EVENT,
&queue->status))) {
xenvif_rx_purge_event(queue);
} else if (!netif_carrier_ok(queue->vif->dev)) {
@@ -2052,15 +2061,24 @@ int xenvif_kthread_guest_rx(void *data)
return 0;
}
+static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
+{
+ /* Dealloc thread must remain running until all inflight
+ * packets complete.
+ */
+ return kthread_should_stop() &&
+ !atomic_read(&queue->inflight_packets);
+}
+
int xenvif_dealloc_kthread(void *data)
{
struct xenvif_queue *queue = data;
- while (!kthread_should_stop()) {
+ for (;;) {
wait_event_interruptible(queue->dealloc_wq,
tx_dealloc_work_todo(queue) ||
- kthread_should_stop());
- if (kthread_should_stop())
+ xenvif_dealloc_kthread_should_stop(queue));
+ if (xenvif_dealloc_kthread_should_stop(queue))
break;
xenvif_tx_dealloc_action(queue);
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 580517d857b..9c47b897b6d 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -116,6 +116,7 @@ static int xenvif_read_io_ring(struct seq_file *m, void *v)
}
#define XENVIF_KICK_STR "kick"
+#define BUFFER_SIZE 32
static ssize_t
xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
@@ -124,22 +125,24 @@ xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
struct xenvif_queue *queue =
((struct seq_file *)filp->private_data)->private;
int len;
- char write[sizeof(XENVIF_KICK_STR)];
+ char write[BUFFER_SIZE];
/* don't allow partial writes and check the length */
if (*ppos != 0)
return 0;
- if (count < sizeof(XENVIF_KICK_STR) - 1)
+ if (count >= sizeof(write))
return -ENOSPC;
len = simple_write_to_buffer(write,
- sizeof(write),
+ sizeof(write) - 1,
ppos,
buf,
count);
if (len < 0)
return len;
+ write[len] = '\0';
+
if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
xenvif_interrupt(0, (void *)queue);
else {
@@ -171,10 +174,9 @@ static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
.write = xenvif_write_io_ring,
};
-static void xenvif_debugfs_addif(struct xenvif_queue *queue)
+static void xenvif_debugfs_addif(struct xenvif *vif)
{
struct dentry *pfile;
- struct xenvif *vif = queue->vif;
int i;
if (IS_ERR_OR_NULL(xen_netback_dbg_root))
@@ -733,10 +735,11 @@ static void connect(struct backend_info *be)
be->vif->num_queues = queue_index;
goto err;
}
+ }
+
#ifdef CONFIG_DEBUG_FS
- xenvif_debugfs_addif(queue);
+ xenvif_debugfs_addif(be->vif);
#endif /* CONFIG_DEBUG_FS */
- }
/* Initialisation completed, tell core driver the number of
* active queues.
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-28 02:30:05 +0000