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path: root/drivers/net/xen-netback/xenbus.c
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Diffstat (limited to 'drivers/net/xen-netback/xenbus.c')
-rw-r--r--drivers/net/xen-netback/xenbus.c182
1 files changed, 153 insertions, 29 deletions
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 7a206cffb062..96c63dc2509e 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -19,6 +19,8 @@
*/
#include "common.h"
+#include <linux/vmalloc.h>
+#include <linux/rtnetlink.h>
struct backend_info {
struct xenbus_device *dev;
@@ -34,8 +36,9 @@ struct backend_info {
u8 have_hotplug_status_watch:1;
};
-static int connect_rings(struct backend_info *);
-static void connect(struct backend_info *);
+static int connect_rings(struct backend_info *be, struct xenvif_queue *queue);
+static void connect(struct backend_info *be);
+static int read_xenbus_vif_flags(struct backend_info *be);
static void backend_create_xenvif(struct backend_info *be);
static void unregister_hotplug_status_watch(struct backend_info *be);
static void set_backend_state(struct backend_info *be,
@@ -157,6 +160,12 @@ static int netback_probe(struct xenbus_device *dev,
if (err)
pr_debug("Error writing feature-split-event-channels\n");
+ /* Multi-queue support: This is an optional feature. */
+ err = xenbus_printf(XBT_NIL, dev->nodename,
+ "multi-queue-max-queues", "%u", xenvif_max_queues);
+ if (err)
+ pr_debug("Error writing multi-queue-max-queues\n");
+
err = xenbus_switch_state(dev, XenbusStateInitWait);
if (err)
goto fail;
@@ -485,10 +494,26 @@ static void connect(struct backend_info *be)
{
int err;
struct xenbus_device *dev = be->dev;
+ unsigned long credit_bytes, credit_usec;
+ unsigned int queue_index;
+ unsigned int requested_num_queues;
+ struct xenvif_queue *queue;
- err = connect_rings(be);
- if (err)
+ /* Check whether the frontend requested multiple queues
+ * and read the number requested.
+ */
+ err = xenbus_scanf(XBT_NIL, dev->otherend,
+ "multi-queue-num-queues",
+ "%u", &requested_num_queues);
+ if (err < 0) {
+ requested_num_queues = 1; /* Fall back to single queue */
+ } else if (requested_num_queues > xenvif_max_queues) {
+ /* buggy or malicious guest */
+ xenbus_dev_fatal(dev, err,
+ "guest requested %u queues, exceeding the maximum of %u.",
+ requested_num_queues, xenvif_max_queues);
return;
+ }
err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
if (err) {
@@ -496,9 +521,54 @@ static void connect(struct backend_info *be)
return;
}
- xen_net_read_rate(dev, &be->vif->credit_bytes,
- &be->vif->credit_usec);
- be->vif->remaining_credit = be->vif->credit_bytes;
+ xen_net_read_rate(dev, &credit_bytes, &credit_usec);
+ read_xenbus_vif_flags(be);
+
+ /* Use the number of queues requested by the frontend */
+ be->vif->queues = vzalloc(requested_num_queues *
+ sizeof(struct xenvif_queue));
+ rtnl_lock();
+ netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
+ rtnl_unlock();
+
+ for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
+ queue = &be->vif->queues[queue_index];
+ queue->vif = be->vif;
+ queue->id = queue_index;
+ snprintf(queue->name, sizeof(queue->name), "%s-q%u",
+ be->vif->dev->name, queue->id);
+
+ err = xenvif_init_queue(queue);
+ if (err) {
+ /* xenvif_init_queue() cleans up after itself on
+ * failure, but we need to clean up any previously
+ * initialised queues. Set num_queues to i so that
+ * earlier queues can be destroyed using the regular
+ * disconnect logic.
+ */
+ rtnl_lock();
+ netif_set_real_num_tx_queues(be->vif->dev, queue_index);
+ rtnl_unlock();
+ goto err;
+ }
+
+ queue->remaining_credit = credit_bytes;
+
+ err = connect_rings(be, queue);
+ if (err) {
+ /* connect_rings() cleans up after itself on failure,
+ * but we need to clean up after xenvif_init_queue() here,
+ * and also clean up any previously initialised queues.
+ */
+ xenvif_deinit_queue(queue);
+ rtnl_lock();
+ netif_set_real_num_tx_queues(be->vif->dev, queue_index);
+ rtnl_unlock();
+ goto err;
+ }
+ }
+
+ xenvif_carrier_on(be->vif);
unregister_hotplug_status_watch(be);
err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
@@ -507,45 +577,109 @@ static void connect(struct backend_info *be)
if (!err)
be->have_hotplug_status_watch = 1;
- netif_wake_queue(be->vif->dev);
+ netif_tx_wake_all_queues(be->vif->dev);
+
+ return;
+
+err:
+ if (be->vif->dev->real_num_tx_queues > 0)
+ xenvif_disconnect(be->vif); /* Clean up existing queues */
+ vfree(be->vif->queues);
+ be->vif->queues = NULL;
+ rtnl_lock();
+ netif_set_real_num_tx_queues(be->vif->dev, 0);
+ rtnl_unlock();
+ return;
}
-static int connect_rings(struct backend_info *be)
+static int connect_rings(struct backend_info *be, struct xenvif_queue *queue)
{
- struct xenvif *vif = be->vif;
struct xenbus_device *dev = be->dev;
+ unsigned int num_queues = queue->vif->dev->real_num_tx_queues;
unsigned long tx_ring_ref, rx_ring_ref;
- unsigned int tx_evtchn, rx_evtchn, rx_copy;
+ unsigned int tx_evtchn, rx_evtchn;
int err;
- int val;
+ char *xspath;
+ size_t xspathsize;
+ const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
+
+ /* If the frontend requested 1 queue, or we have fallen back
+ * to single queue due to lack of frontend support for multi-
+ * queue, expect the remaining XenStore keys in the toplevel
+ * directory. Otherwise, expect them in a subdirectory called
+ * queue-N.
+ */
+ if (num_queues == 1) {
+ xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
+ if (!xspath) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "reading ring references");
+ return -ENOMEM;
+ }
+ strcpy(xspath, dev->otherend);
+ } else {
+ xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
+ xspath = kzalloc(xspathsize, GFP_KERNEL);
+ if (!xspath) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "reading ring references");
+ return -ENOMEM;
+ }
+ snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
+ queue->id);
+ }
- err = xenbus_gather(XBT_NIL, dev->otherend,
+ err = xenbus_gather(XBT_NIL, xspath,
"tx-ring-ref", "%lu", &tx_ring_ref,
"rx-ring-ref", "%lu", &rx_ring_ref, NULL);
if (err) {
xenbus_dev_fatal(dev, err,
"reading %s/ring-ref",
- dev->otherend);
- return err;
+ xspath);
+ goto err;
}
/* Try split event channels first, then single event channel. */
- err = xenbus_gather(XBT_NIL, dev->otherend,
+ err = xenbus_gather(XBT_NIL, xspath,
"event-channel-tx", "%u", &tx_evtchn,
"event-channel-rx", "%u", &rx_evtchn, NULL);
if (err < 0) {
- err = xenbus_scanf(XBT_NIL, dev->otherend,
+ err = xenbus_scanf(XBT_NIL, xspath,
"event-channel", "%u", &tx_evtchn);
if (err < 0) {
xenbus_dev_fatal(dev, err,
"reading %s/event-channel(-tx/rx)",
- dev->otherend);
- return err;
+ xspath);
+ goto err;
}
rx_evtchn = tx_evtchn;
}
+ /* Map the shared frame, irq etc. */
+ err = xenvif_connect(queue, tx_ring_ref, rx_ring_ref,
+ tx_evtchn, rx_evtchn);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "mapping shared-frames %lu/%lu port tx %u rx %u",
+ tx_ring_ref, rx_ring_ref,
+ tx_evtchn, rx_evtchn);
+ goto err;
+ }
+
+ err = 0;
+err: /* Regular return falls through with err == 0 */
+ kfree(xspath);
+ return err;
+}
+
+static int read_xenbus_vif_flags(struct backend_info *be)
+{
+ struct xenvif *vif = be->vif;
+ struct xenbus_device *dev = be->dev;
+ unsigned int rx_copy;
+ int err, val;
+
err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
&rx_copy);
if (err == -ENOENT) {
@@ -621,16 +755,6 @@ static int connect_rings(struct backend_info *be)
val = 0;
vif->ipv6_csum = !!val;
- /* Map the shared frame, irq etc. */
- err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref,
- tx_evtchn, rx_evtchn);
- if (err) {
- xenbus_dev_fatal(dev, err,
- "mapping shared-frames %lu/%lu port tx %u rx %u",
- tx_ring_ref, rx_ring_ref,
- tx_evtchn, rx_evtchn);
- return err;
- }
return 0;
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-05 19:31:46 +0000