diff mbox series

[net-next,v2,05/10] gve: Make gve_turnup work for nonempty queues

Message ID 20240501232549.1327174-6-shailend@google.com (mailing list archive)
State Accepted
Commit 864616d97a4505a719d5f67c29d31776038d39ef
Delegated to: Netdev Maintainers
Headers show
Series gve: Implement queue api | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 926 this patch: 926
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 937 this patch: 937
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 937 this patch: 937
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 26 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-05-05--03-00 (tests: 1003)

Commit Message

Shailend Chand May 1, 2024, 11:25 p.m. UTC 
gVNIC has a requirement that all queues have to be quiesced before any
queue is operated on (created or destroyed). To enable the
implementation of future ndo hooks that work on a single queue, we need
to evolve gve_turnup to account for queues already having some
unprocessed descriptors in the ring.

Say rxq 4 is being stopped and started via the queue api. Due to gve's
requirement of quiescence, queues 0 through 3 are not processing their
rings while queue 4 is being toggled. Once they are made live, these
queues need to be poked to cause them to check their rings for
descriptors that were written during their brief period of quiescence.

Tested-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Signed-off-by: Shailend Chand <shailend@google.com>
---
 drivers/net/ethernet/google/gve/gve_main.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index 469a914c71d6..ef902b72b9a9 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -1979,6 +1979,13 @@  static void gve_turnup(struct gve_priv *priv)
 			gve_set_itr_coalesce_usecs_dqo(priv, block,
 						       priv->tx_coalesce_usecs);
 		}
+
+		/* Any descs written by the NIC before this barrier will be
+		 * handled by the one-off napi schedule below. Whereas any
+		 * descs after the barrier will generate interrupts.
+		 */
+		mb();
+		napi_schedule(&block->napi);
 	}
 	for (idx = 0; idx < priv->rx_cfg.num_queues; idx++) {
 		int ntfy_idx = gve_rx_idx_to_ntfy(priv, idx);
@@ -1994,6 +2001,13 @@  static void gve_turnup(struct gve_priv *priv)
 			gve_set_itr_coalesce_usecs_dqo(priv, block,
 						       priv->rx_coalesce_usecs);
 		}
+
+		/* Any descs written by the NIC before this barrier will be
+		 * handled by the one-off napi schedule below. Whereas any
+		 * descs after the barrier will generate interrupts.
+		 */
+		mb();
+		napi_schedule(&block->napi);
 	}
 
 	gve_set_napi_enabled(priv);