[dpdk-dev] [PATCH] vhost: reset device properly
Yuanhan Liu
yuanhan.liu at linux.intel.com
Thu Nov 12 05:10:41 CET 2015
Currently, we reset all fields of a device to zero when reset
happens, which is wrong, since for some fields like device_fh,
ifname, and virt_qp_nb, they should be same and be kept after
reset until the device is removed. And this is what's the new
helper function reset_device() for.
And use rte_zmalloc() instead of rte_malloc, so that we could
avoid init_device(), which basically dose zero reset only so far.
Hence, init_device() is dropped in this patch.
This patch also removes a hack of using the offset a specific
field (which is virtqueue now) inside of `virtio_net' structure
to do reset, which could be broken easily if someone changed the
field order without caution.
Cc: Tetsuya Mukawa <mukawa at igel.co.jp>
Cc: Xie Huawei <huawei.xie at intel.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
This patch is based on:
http://dpdk.org/dev/patchwork/patch/8818/
---
lib/librte_vhost/virtio-net.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 39a6a5e..cc917da 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -204,6 +204,7 @@ cleanup_device(struct virtio_net *dev)
munmap((void *)(uintptr_t)dev->mem->mapped_address,
(size_t)dev->mem->mapped_size);
free(dev->mem);
+ dev->mem = NULL;
}
for (i = 0; i < dev->virt_qp_nb; i++) {
@@ -306,20 +307,18 @@ alloc_vring_queue_pair(struct virtio_net *dev, uint32_t qp_idx)
}
/*
- * Initialise all variables in device structure.
+ * Reset some variables in device structure, while keeping few
+ * others untouched, such as device_fh, ifname, virt_qp_nb: they
+ * should be same unless the device is removed.
*/
static void
-init_device(struct virtio_net *dev)
+reset_device(struct virtio_net *dev)
{
- int vq_offset;
uint32_t i;
- /*
- * Virtqueues have already been malloced so
- * we don't want to set them to NULL.
- */
- vq_offset = offsetof(struct virtio_net, virtqueue);
- memset(dev, 0, vq_offset);
+ dev->features = 0;
+ dev->protocol_features = 0;
+ dev->flags = 0;
for (i = 0; i < dev->virt_qp_nb; i++)
init_vring_queue_pair(dev, i);
@@ -336,7 +335,7 @@ new_device(struct vhost_device_ctx ctx)
struct virtio_net_config_ll *new_ll_dev;
/* Setup device and virtqueues. */
- new_ll_dev = rte_malloc(NULL, sizeof(struct virtio_net_config_ll), 0);
+ new_ll_dev = rte_zmalloc(NULL, sizeof(struct virtio_net_config_ll), 0);
if (new_ll_dev == NULL) {
RTE_LOG(ERR, VHOST_CONFIG,
"(%"PRIu64") Failed to allocate memory for dev.\n",
@@ -344,9 +343,6 @@ new_device(struct vhost_device_ctx ctx)
return -1;
}
- /* Initialise device and virtqueues. */
- init_device(&new_ll_dev->dev);
-
new_ll_dev->next = NULL;
/* Add entry to device configuration linked list. */
@@ -430,7 +426,6 @@ static int
reset_owner(struct vhost_device_ctx ctx)
{
struct virtio_net *dev;
- uint64_t device_fh;
dev = get_device(ctx);
if (dev == NULL)
@@ -439,10 +434,8 @@ reset_owner(struct vhost_device_ctx ctx)
if (dev->flags & VIRTIO_DEV_RUNNING)
notify_ops->destroy_device(dev);
- device_fh = dev->device_fh;
cleanup_device(dev);
- init_device(dev);
- dev->device_fh = device_fh;
+ reset_device(dev);
return 0;
}
--
1.9.0
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