1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316
|
From 5fe1b16f4eedda3a3bdceb2a0f65a0e7816555ab Mon Sep 17 00:00:00 2001
From: Zoltan Kiss <zoltan.kiss@citrix.com>
Date: Tue, 8 Jul 2014 19:49:14 +0100
Subject: [PATCH 01/14] xen-netback: Adding debugfs "io_ring_qX" files
Origin: https://git.kernel.org/linus/f51de24356e49e4dcb5095e87717065580912120
This patch adds debugfs capabilities to netback. There used to be a similar
patch floating around for classic kernel, but it used procfs. It is based on a
very similar blkback patch.
It creates xen-netback/[vifname]/io_ring_q[queueno] files, reading them output
various ring variables etc. Writing "kick" into it imitates an interrupt
happened, it can be useful to check whether the ring is just stalled due to a
missed interrupt.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit f51de24356e49e4dcb5095e87717065580912120)
---
drivers/net/xen-netback/common.h | 11 +++
drivers/net/xen-netback/interface.c | 2 +-
drivers/net/xen-netback/netback.c | 11 +++
drivers/net/xen-netback/xenbus.c | 178 ++++++++++++++++++++++++++++++++++-
4 files changed, 200 insertions(+), 2 deletions(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 2532ce8..28c9822 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -44,6 +44,7 @@
#include <xen/interface/grant_table.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
+#include <linux/debugfs.h>
typedef unsigned int pending_ring_idx_t;
#define INVALID_PENDING_RING_IDX (~0U)
@@ -224,6 +225,10 @@ struct xenvif {
struct xenvif_queue *queues;
unsigned int num_queues; /* active queues, resource allocated */
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *xenvif_dbg_root;
+#endif
+
/* Miscellaneous private stuff. */
struct net_device *dev;
};
@@ -297,10 +302,16 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
/* Callback from stack when TX packet can be released */
void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
+irqreturn_t xenvif_interrupt(int irq, void *dev_id);
+
extern bool separate_tx_rx_irq;
extern unsigned int rx_drain_timeout_msecs;
extern unsigned int rx_drain_timeout_jiffies;
extern unsigned int xenvif_max_queues;
+#ifdef CONFIG_DEBUG_FS
+extern struct dentry *xen_netback_dbg_root;
+#endif
+
#endif /* __XEN_NETBACK__COMMON_H__ */
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 9e97c7c..ef75b45 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -102,7 +102,7 @@ static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
+irqreturn_t xenvif_interrupt(int irq, void *dev_id)
{
xenvif_tx_interrupt(irq, dev_id);
xenvif_rx_interrupt(irq, dev_id);
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index c65b636..769e553 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -2027,6 +2027,13 @@ static int __init netback_init(void)
rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs);
+#ifdef CONFIG_DEBUG_FS
+ xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
+ if (IS_ERR_OR_NULL(xen_netback_dbg_root))
+ pr_warn("Init of debugfs returned %ld!\n",
+ PTR_ERR(xen_netback_dbg_root));
+#endif /* CONFIG_DEBUG_FS */
+
return 0;
failed_init:
@@ -2037,6 +2044,10 @@ module_init(netback_init);
static void __exit netback_fini(void)
{
+#ifdef CONFIG_DEBUG_FS
+ if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
+ debugfs_remove_recursive(xen_netback_dbg_root);
+#endif /* CONFIG_DEBUG_FS */
xenvif_xenbus_fini();
}
module_exit(netback_fini);
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 3d85acd..580517d 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -44,6 +44,175 @@ static void unregister_hotplug_status_watch(struct backend_info *be);
static void set_backend_state(struct backend_info *be,
enum xenbus_state state);
+#ifdef CONFIG_DEBUG_FS
+struct dentry *xen_netback_dbg_root = NULL;
+
+static int xenvif_read_io_ring(struct seq_file *m, void *v)
+{
+ struct xenvif_queue *queue = m->private;
+ struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
+ struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
+
+ if (tx_ring->sring) {
+ struct xen_netif_tx_sring *sring = tx_ring->sring;
+
+ seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
+ tx_ring->nr_ents);
+ seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
+ sring->req_prod,
+ sring->req_prod - sring->rsp_prod,
+ tx_ring->req_cons,
+ tx_ring->req_cons - sring->rsp_prod,
+ sring->req_event,
+ sring->req_event - sring->rsp_prod);
+ seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
+ sring->rsp_prod,
+ tx_ring->rsp_prod_pvt,
+ tx_ring->rsp_prod_pvt - sring->rsp_prod,
+ sring->rsp_event,
+ sring->rsp_event - sring->rsp_prod);
+ seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
+ queue->pending_prod,
+ queue->pending_cons,
+ nr_pending_reqs(queue));
+ seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
+ queue->dealloc_prod,
+ queue->dealloc_cons,
+ queue->dealloc_prod - queue->dealloc_cons);
+ }
+
+ if (rx_ring->sring) {
+ struct xen_netif_rx_sring *sring = rx_ring->sring;
+
+ seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
+ seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
+ sring->req_prod,
+ sring->req_prod - sring->rsp_prod,
+ rx_ring->req_cons,
+ rx_ring->req_cons - sring->rsp_prod,
+ sring->req_event,
+ sring->req_event - sring->rsp_prod);
+ seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
+ sring->rsp_prod,
+ rx_ring->rsp_prod_pvt,
+ rx_ring->rsp_prod_pvt - sring->rsp_prod,
+ sring->rsp_event,
+ sring->rsp_event - sring->rsp_prod);
+ }
+
+ seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
+ "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
+ "remaining: %lu, expires: %lu, now: %lu\n",
+ queue->napi.state, queue->napi.weight,
+ skb_queue_len(&queue->tx_queue),
+ timer_pending(&queue->credit_timeout),
+ queue->credit_bytes,
+ queue->credit_usec,
+ queue->remaining_credit,
+ queue->credit_timeout.expires,
+ jiffies);
+
+ return 0;
+}
+
+#define XENVIF_KICK_STR "kick"
+
+static ssize_t
+xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct xenvif_queue *queue =
+ ((struct seq_file *)filp->private_data)->private;
+ int len;
+ char write[sizeof(XENVIF_KICK_STR)];
+
+ /* don't allow partial writes and check the length */
+ if (*ppos != 0)
+ return 0;
+ if (count < sizeof(XENVIF_KICK_STR) - 1)
+ return -ENOSPC;
+
+ len = simple_write_to_buffer(write,
+ sizeof(write),
+ ppos,
+ buf,
+ count);
+ if (len < 0)
+ return len;
+
+ if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
+ xenvif_interrupt(0, (void *)queue);
+ else {
+ pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
+ queue->id);
+ count = -EINVAL;
+ }
+ return count;
+}
+
+static int xenvif_dump_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+ void *queue = NULL;
+
+ if (inode->i_private)
+ queue = inode->i_private;
+ ret = single_open(filp, xenvif_read_io_ring, queue);
+ filp->f_mode |= FMODE_PWRITE;
+ return ret;
+}
+
+static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
+ .owner = THIS_MODULE,
+ .open = xenvif_dump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .write = xenvif_write_io_ring,
+};
+
+static void xenvif_debugfs_addif(struct xenvif_queue *queue)
+{
+ struct dentry *pfile;
+ struct xenvif *vif = queue->vif;
+ int i;
+
+ if (IS_ERR_OR_NULL(xen_netback_dbg_root))
+ return;
+
+ vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
+ xen_netback_dbg_root);
+ if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
+ for (i = 0; i < vif->num_queues; ++i) {
+ char filename[sizeof("io_ring_q") + 4];
+
+ snprintf(filename, sizeof(filename), "io_ring_q%d", i);
+ pfile = debugfs_create_file(filename,
+ S_IRUSR | S_IWUSR,
+ vif->xenvif_dbg_root,
+ &vif->queues[i],
+ &xenvif_dbg_io_ring_ops_fops);
+ if (IS_ERR_OR_NULL(pfile))
+ pr_warn("Creation of io_ring file returned %ld!\n",
+ PTR_ERR(pfile));
+ }
+ } else
+ netdev_warn(vif->dev,
+ "Creation of vif debugfs dir returned %ld!\n",
+ PTR_ERR(vif->xenvif_dbg_root));
+}
+
+static void xenvif_debugfs_delif(struct xenvif *vif)
+{
+ if (IS_ERR_OR_NULL(xen_netback_dbg_root))
+ return;
+
+ if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
+ debugfs_remove_recursive(vif->xenvif_dbg_root);
+ vif->xenvif_dbg_root = NULL;
+}
+#endif /* CONFIG_DEBUG_FS */
+
static int netback_remove(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
@@ -246,8 +415,12 @@ static void backend_create_xenvif(struct backend_info *be)
static void backend_disconnect(struct backend_info *be)
{
- if (be->vif)
+ if (be->vif) {
+#ifdef CONFIG_DEBUG_FS
+ xenvif_debugfs_delif(be->vif);
+#endif /* CONFIG_DEBUG_FS */
xenvif_disconnect(be->vif);
+ }
}
static void backend_connect(struct backend_info *be)
@@ -560,6 +733,9 @@ static void connect(struct backend_info *be)
be->vif->num_queues = queue_index;
goto err;
}
+#ifdef CONFIG_DEBUG_FS
+ xenvif_debugfs_addif(queue);
+#endif /* CONFIG_DEBUG_FS */
}
/* Initialisation completed, tell core driver the number of
--
1.7.10.4
|