[dpdk-dev] [PATCH 18.05-RC3 2/2] net/virtio-user: support memory hotplug
Xiao Wang
xiao.w.wang at intel.com
Tue May 8 09:10:45 CEST 2018
From: Maxime Coquelin <maxime.coquelin at redhat.com>
When memory is hot-added or hot-removed, the virtio-user driver has to
notify the vhost-user backend with sending a VHOST_USER_SET_MEM_TABLE
request with the new memory map as payload.
This patch implements and registers a mem_event callback, it pauses the
datapath and updates memory regions to vhost in case of hot-add or
hot-remove event. This memory region update has only to be done when the
device is already started, so a new status flag is added to the device to
keep track of the status.
As the device can now be managed by different threads, a mutex is
introduced to protect against concurrent device configuration.
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Signed-off-by: Xiao Wang <xiao.w.wang at intel.com>
---
drivers/net/virtio/virtio_user/virtio_user_dev.c | 53 +++++++++++++++++++++++-
drivers/net/virtio/virtio_user/virtio_user_dev.h | 2 +
2 files changed, 54 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 38b8bc90d..6522bec3f 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -17,6 +17,8 @@
#include "virtio_user_dev.h"
#include "../virtio_ethdev.h"
+#define VIRTIO_USER_MEM_EVENT_CLB_NAME "virtio_user_mem_event_clb"
+
static int
virtio_user_create_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
{
@@ -110,8 +112,10 @@ virtio_user_start_device(struct virtio_user_dev *dev)
uint64_t features;
int ret;
+ pthread_mutex_lock(&dev->mutex);
+
if (is_vhost_user_by_type(dev->path) && dev->vhostfd < 0)
- return -1;
+ goto error;
/* Do not check return as already done in init, or reset in stop */
dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL);
@@ -146,8 +150,12 @@ virtio_user_start_device(struct virtio_user_dev *dev)
*/
dev->ops->enable_qp(dev, 0, 1);
+ dev->started = true;
+ pthread_mutex_unlock(&dev->mutex);
+
return 0;
error:
+ pthread_mutex_unlock(&dev->mutex);
/* TODO: free resource here or caller to check */
return -1;
}
@@ -156,13 +164,17 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
{
uint32_t i;
+ pthread_mutex_lock(&dev->mutex);
for (i = 0; i < dev->max_queue_pairs; ++i)
dev->ops->enable_qp(dev, i, 0);
if (dev->ops->send_request(dev, VHOST_USER_RESET_OWNER, NULL) < 0) {
PMD_DRV_LOG(INFO, "Failed to reset the device\n");
+ pthread_mutex_unlock(&dev->mutex);
return -1;
}
+ dev->started = false;
+ pthread_mutex_unlock(&dev->mutex);
return 0;
}
@@ -263,6 +275,35 @@ virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
return 0;
}
+static void
+virtio_user_mem_event_cb(enum rte_mem_event type __rte_unused,
+ const void *addr __rte_unused,
+ size_t len __rte_unused,
+ void *arg)
+{
+ struct virtio_user_dev *dev = arg;
+ uint16_t i;
+
+ pthread_mutex_lock(&dev->mutex);
+
+ if (dev->started == false)
+ goto exit;
+
+ /* Step 1: pause the active queues */
+ for (i = 0; i < dev->queue_pairs; i++)
+ dev->ops->enable_qp(dev, i, 0);
+
+ /* Step 2: update memory regions */
+ dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
+
+ /* Step 3: resume the active queues */
+ for (i = 0; i < dev->queue_pairs; i++)
+ dev->ops->enable_qp(dev, i, 1);
+
+exit:
+ pthread_mutex_unlock(&dev->mutex);
+}
+
static int
virtio_user_dev_setup(struct virtio_user_dev *dev)
{
@@ -336,7 +377,9 @@ int
virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
int cq, int queue_size, const char *mac, char **ifname)
{
+ pthread_mutex_init(&dev->mutex, NULL);
snprintf(dev->path, PATH_MAX, "%s", path);
+ dev->started = 0;
dev->max_queue_pairs = queues;
dev->queue_pairs = 1; /* mq disabled by default */
dev->queue_size = queue_size;
@@ -400,6 +443,12 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
dev->device_features &= VIRTIO_USER_SUPPORTED_FEATURES;
+ if (rte_mem_event_callback_register(VIRTIO_USER_MEM_EVENT_CLB_NAME,
+ virtio_user_mem_event_cb, dev)) {
+ PMD_INIT_LOG(ERR, "Failed to register mem event callback\n");
+ return -1;
+ }
+
return 0;
}
@@ -410,6 +459,8 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
virtio_user_stop_device(dev);
+ rte_mem_event_callback_unregister(VIRTIO_USER_MEM_EVENT_CLB_NAME, dev);
+
for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
close(dev->callfds[i]);
close(dev->kickfds[i]);
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index ade727e46..cadff0cba 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -39,6 +39,8 @@ struct virtio_user_dev {
char path[PATH_MAX];
struct vring vrings[VIRTIO_MAX_VIRTQUEUES];
struct virtio_user_backend_ops *ops;
+ pthread_mutex_t mutex;
+ bool started;
};
int is_vhost_user_by_type(const char *path);
--
2.15.1
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