7 Commits

Author SHA1 Message Date
Ameer Hamza
e6f60c51f0 gve: fix for null pointer dereference.
Avoid passing NULL skb to __skb_put() function call if
napi_alloc_skb() returns NULL.

Fixes: 37149e9374bf ("gve: Implement packet continuation for RX.")
Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
Link: https://lore.kernel.org/r/20211205183810.8299-1-amhamza.mgc@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-07 20:57:17 -08:00
David Awogbemila
37149e9374 gve: Implement packet continuation for RX.
This enables the driver to receive RX packets spread across multiple
buffers:

For a given multi-fragment packet the "packet continuation" bit is set
on all descriptors except the last one. These descriptors' payloads are
combined into a single SKB before the SKB is handed to the
networking stack.

This change adds a "packet buffer size" notion for RX queues. The
CreateRxQueue AdminQueue command sent to the device now includes the
packet_buffer_size.

We opt for a packet_buffer_size of PAGE_SIZE / 2 to give the
driver the opportunity to flip pages where we can instead of copying.

Signed-off-by: David Awogbemila <awogbemila@google.com>
Signed-off-by: Jeroen de Borst <jeroendb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-25 14:13:12 +01:00
Catherine Sullivan
4edf8249bc gve: Add netif_set_xps_queue call
Configure XPS when adding tx queues to the notification blocks.

Fixes: dbdaa67540512 ("gve: Move some static functions to a common file")
Signed-off-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David Awogbemila <awogbemila@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-11 23:25:36 +01:00
Bailey Forrest
9b8dd5e5ea gve: DQO: Add RX path
The RX queue has an array of `gve_rx_buf_state_dqo` objects. All
allocated pages have an associated buf_state object. When a buffer is
posted on the RX buffer queue, the buffer ID will be the buf_state's
index into the RX queue's array.

On packet reception, the RX queue will have one descriptor for each
buffer associated with a received packet. Each RX descriptor will have
a buffer_id that was posted on the buffer queue.

Notable mentions:

- We use a default buffer size of 2048 bytes. Based on page size, we
  may post separate sections of a single page as separate buffers.

- The driver holds an extra reference on pages passed up the receive
  path with an skb and keeps these pages on a list. When posting new
  buffers to the NIC, we check if any of these pages has only our
  reference, or another buffer sized segment of the page has no
  references. If so, it is free to reuse. This page recycling approach
  is a common netdev optimization that reduces page alloc/free calls.

- Pages in the free list have a page_count bias in order to avoid an
  atomic increment of pagecount every time we attempt to reuse a page.
  # references = page_count() - bias

- In order to track when a page is safe to reuse, we keep track of the
  last offset which had a single SKB reference. When this occurs, it
  implies that every single other offset is reusable. Otherwise, we
  don't know if offsets can be safely reused.

- We maintain two free lists of pages. List #1 (recycled_buf_states)
  contains pages we know can be reused right away. List #2
  (used_buf_states) contains pages which cannot be used right away. We
  only attempt to get pages from list #2 when list #1 is empty. We only
  attempt to use a small fixed number pages from list #2 before giving
  up and allocating a new page. Both lists are FIFOs in hope that by the
  time we attempt to reuse a page, the references were dropped.

Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-24 12:47:38 -07:00
Bailey Forrest
920fb45193 gve: Make gve_rx_slot_page_info.page_offset an absolute offset
Using `page_offset` like a boolean means a page may only be split into
two sections. With page sizes larger than 4k, this can be very wasteful.
Future commits in this patchset use `struct gve_rx_slot_page_info` in a
way which supports a fixed buffer size and a variable page size.

Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-24 12:47:37 -07:00
Bailey Forrest
35f9b2f43f gve: gve_rx_copy: Move padding to an argument
Future use cases will have a different padding value.

Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-24 12:47:37 -07:00
Bailey Forrest
dbdaa67540 gve: Move some static functions to a common file
These functions will be shared by the GQI and DQO variants of the GVNIC
driver as of follow-up patches in this series.

Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-24 12:47:37 -07:00