A netdev provider, especially a PMD provider (like netdev DPDK) might
not be able to change some of its parameters (such as MTU, or number of
queues) without stopping everything and restarting.
This commit introduces a mechanism that allows a netdev provider to
request a restart (netdev_request_reconfigure()). The upper layer can
be notified via netdev_wait_reconf_required() and
netdev_is_reconf_required(). After closing all the rxqs the upper layer
can finally call netdev_reconfigure(), to make sure that the new
configuration is in place.
This will be used by next commit to reconfigure rx and tx queues in
netdev-dpdk.
Signed-off-by: Daniele Di Proietto <diproiet...@vmware.com>
---
lib/netdev-bsd.c | 1 +
lib/netdev-dpdk.c | 1 +
lib/netdev-dummy.c | 1 +
lib/netdev-linux.c | 1 +
lib/netdev-provider.h | 23 ++++++++++++++++++++++-
lib/netdev-vport.c | 1 +
lib/netdev.c | 29 +++++++++++++++++++++++++++++
lib/netdev.h | 4 ++++
8 files changed, 60 insertions(+), 1 deletion(-)
diff --git a/lib/netdev-bsd.c b/lib/netdev-bsd.c
index edf04bf..724e6d4 100644
--- a/lib/netdev-bsd.c
+++ b/lib/netdev-bsd.c
@@ -1602,6 +1602,7 @@ netdev_bsd_update_flags(struct netdev *netdev_, enum
netdev_flags off,
netdev_bsd_arp_lookup, /* arp_lookup */ \
\
netdev_bsd_update_flags, \
+ NULL, /* reconfigure */ \
\
netdev_bsd_rxq_alloc, \
netdev_bsd_rxq_construct, \
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index b3518b8..a48ca71 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -2298,6 +2298,7 @@ unlock_dpdk:
NULL, /* arp_lookup */ \
\
netdev_dpdk_update_flags, \
+ NULL, /* reconfigure */ \
\
netdev_dpdk_rxq_alloc, \
netdev_dpdk_rxq_construct, \
diff --git a/lib/netdev-dummy.c b/lib/netdev-dummy.c
index ccd4a0a..d7524eb 100644
--- a/lib/netdev-dummy.c
+++ b/lib/netdev-dummy.c
@@ -1251,6 +1251,7 @@ static const struct netdev_class dummy_class = {
NULL, /* arp_lookup */
netdev_dummy_update_flags,
+ NULL, /* reconfigure */
netdev_dummy_rxq_alloc,
netdev_dummy_rxq_construct,
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index d58c1b1..d7599c3 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -2888,6 +2888,7 @@ netdev_linux_update_flags(struct netdev *netdev_, enum
netdev_flags off,
netdev_linux_arp_lookup, \
\
netdev_linux_update_flags, \
+ NULL, /* reconfigure */ \
\
netdev_linux_rxq_alloc, \
netdev_linux_rxq_construct, \
diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
index 2aa1b5d..9646cca 100644
--- a/lib/netdev-provider.h
+++ b/lib/netdev-provider.h
@@ -52,6 +52,16 @@ struct netdev {
* 'netdev''s flags, features, ethernet address, or carrier changes. */
uint64_t change_seq;
+ /* A netdev provider might be unable to change some of the device's
+ * parameter (n_rxq, mtu) when the device is in use. In this case
+ * the provider can notify the upper layer by calling
+ * netdev_request_reconfigure(). The upper layer will react by stopping
+ * the operations on the device and calling netdev_reconfigure() to allow
+ * the configuration changes. 'last_reconfigure_seq' remembers the value
+ * of 'reconfigure_seq' when the last reconfiguration happened. */
+ struct seq *reconfigure_seq;
+ uint64_t last_reconfigure_seq;
+
/* The core netdev code initializes these at netdev construction and only
* provide read-only access to its client. Netdev implementations may
* modify them. */
@@ -64,7 +74,7 @@ struct netdev {
struct ovs_list saved_flags_list; /* Contains "struct netdev_saved_flags".
*/
};
-static void
+static inline void
netdev_change_seq_changed(const struct netdev *netdev_)
{
struct netdev *netdev = CONST_CAST(struct netdev *, netdev_);
@@ -75,6 +85,12 @@ netdev_change_seq_changed(const struct netdev *netdev_)
}
}
+static inline void
+netdev_request_reconfigure(struct netdev *netdev)
+{
+ seq_change(netdev->reconfigure_seq);
+}
+
const char *netdev_get_type(const struct netdev *);
const struct netdev_class *netdev_get_class(const struct netdev *);
const char *netdev_get_name(const struct netdev *);
@@ -699,6 +715,11 @@ struct netdev_class {
int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
enum netdev_flags on, enum netdev_flags *old_flags);
+ /* If the provider called netdev_request_reconfigure(), the upper layer
+ * will eventually call this. The provider can update the device
+ * configuration knowing that the upper layer will not call rxq_recv() or
+ * send() until this function returns. */
+ int (*reconfigure)(struct netdev *netdev);
/* ## -------------------- ## */
/* ## netdev_rxq Functions ## */
/* ## -------------------- ## */
diff --git a/lib/netdev-vport.c b/lib/netdev-vport.c
index df6d8cf..d055f10 100644
--- a/lib/netdev-vport.c
+++ b/lib/netdev-vport.c
@@ -1537,6 +1537,7 @@ netdev_vport_range(struct unixctl_conn *conn, int argc,
NULL, /* arp_lookup */ \
\
netdev_vport_update_flags, \
+ NULL, /* reconfigure */ \
\
NULL, /* rx_alloc */ \
NULL, /* rx_construct */ \
diff --git a/lib/netdev.c b/lib/netdev.c
index ee92e01..2c0918b 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -377,6 +377,8 @@ netdev_open(const char *name, const char *type, struct
netdev **netdevp)
netdev->netdev_class = rc->class;
netdev->name = xstrdup(name);
netdev->change_seq = 1;
+ netdev->reconfigure_seq = seq_create();
+ netdev->last_reconfigure_seq =
seq_read(netdev->reconfigure_seq);
netdev->node = shash_add(&netdev_shash, name, netdev);
/* By default enable one tx and rx queue per netdev. */
@@ -525,6 +527,7 @@ netdev_unref(struct netdev *dev)
shash_delete(&netdev_shash, dev->node);
}
free(dev->name);
+ seq_destroy(dev->reconfigure_seq);
dev->netdev_class->dealloc(dev);
ovs_mutex_unlock(&netdev_mutex);
@@ -1854,3 +1857,29 @@ netdev_get_change_seq(const struct netdev *netdev)
{
return netdev->change_seq;
}
+
+void
+netdev_wait_reconf_required(struct netdev *netdev)
+{
+ seq_wait(netdev->reconfigure_seq, netdev->last_reconfigure_seq);
+}
+
+bool
+netdev_is_reconf_required(struct netdev *netdev)
+{
+ return seq_read(netdev->reconfigure_seq) != netdev->last_reconfigure_seq;
+}
+
+/* When this function is called, no concurrent call to netdev_rxq_recv() or
+ * netdev_send() must be issued. */
+int
+netdev_reconfigure(struct netdev *netdev)
+{
+ const struct netdev_class *class = netdev->netdev_class;
+
+ netdev->last_reconfigure_seq = seq_read(netdev->reconfigure_seq);
+
+ return (class->reconfigure
+ ? class->reconfigure(netdev)
+ : EOPNOTSUPP);
+}
diff --git a/lib/netdev.h b/lib/netdev.h
index a81989e..c2a1d6c 100644
--- a/lib/netdev.h
+++ b/lib/netdev.h
@@ -308,6 +308,10 @@ int netdev_get_queue_stats(const struct netdev *, unsigned
int queue_id,
struct netdev_queue_stats *);
uint64_t netdev_get_change_seq(const struct netdev *);
+int netdev_reconfigure(struct netdev *netdev);
+void netdev_wait_reconf_required(struct netdev *netdev);
+bool netdev_is_reconf_required(struct netdev *netdev);
+
struct netdev_queue_dump {
struct netdev *netdev;
int error;
--
2.1.4
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