Willem de Bruijn 497dbb2b97 gve: Add optional metadata descriptor type GVE_TXD_MTD ... Allow drivers to pass metadata along with packet data to the device. Introduce a new metadata descriptor type * GVE_TXD_MTD This descriptor is optional. If present it immediate follows the packet descriptor and precedes the segment descriptor. This descriptor may be repeated. Multiple metadata descriptors may follow. There are no immediate uses for this, this is for future proofing. At present devices allow only 1 MTD descriptor. The lower four bits of the type_flags field encode GVE_TXD_MTD. The upper four bits of the type_flags field encodes a *sub*type. Introduce one such metadata descriptor subtype * GVE_MTD_SUBTYPE_PATH This shares path information with the device for network failure discovery and robust response: Linux derives ipv6 flowlabel and ECMP multipath from sk->sk_txhash, and updates this field on error with sk_rethink_txhash. Allow the host stack to do the same. Pass the tx_hash value if set. Also communicate whether the path hash is set, or more exactly, what its type is. Define two common types GVE_MTD_PATH_HASH_NONE GVE_MTD_PATH_HASH_L4 Concrete examples of error conditions that are resolved are mentioned in the commits that add sk_rethink_txhash calls. Such as commit 7788174e87 ("tcp: change IPv6 flow-label upon receiving spurious retransmission"). Experimental results mirror what the theory suggests: where IPv6 FlowLabel is included in path selection (e.g., LAG/ECMP), flowlabel rotation on TCP timeout avoids the vast majority of TCP disconnects that would otherwise have occurred during link failures in long-haul backbones, when an alternative path is available. Rotation can be applied to various bad connection signals, such as timeouts and spurious retransmissions. In aggregate, such flow level signals can help locate network issues. Define initial common states: GVE_MTD_PATH_STATE_DEFAULT GVE_MTD_PATH_STATE_TIMEOUT GVE_MTD_PATH_STATE_CONGESTION GVE_MTD_PATH_STATE_RETRANSMIT Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David Awogbemila <awogbemila@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2021-12-16 10:41:54 +00:00
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gve.h	gve: Add optional metadata descriptor type GVE_TXD_MTD	2021-12-16 10:41:54 +00:00
gve_adminq.c	gve: Move the irq db indexes out of the ntfy block struct	2021-12-16 10:41:53 +00:00
gve_adminq.h	gve: Add a jumbo-frame device option.	2021-10-25 14:13:12 +01:00
gve_desc.h	gve: Add optional metadata descriptor type GVE_TXD_MTD	2021-12-16 10:41:54 +00:00
gve_desc_dqo.h	gve: Add dqo descriptors	2021-06-24 12:47:37 -07:00
gve_dqo.h	gve: Move the irq db indexes out of the ntfy block struct	2021-12-16 10:41:53 +00:00
gve_ethtool.c	ethtool: extend ringparam setting/getting API with rx_buf_len	2021-11-22 12:31:49 +00:00
gve_main.c	gve: Update gve_free_queue_page_list signature	2021-12-16 10:41:53 +00:00
gve_register.h	gve: Add Gvnic stats AQ command and ethtool show/set-priv-flags.	2020-09-11 14:31:54 -07:00
gve_rx.c	gve: remove memory barrier around seqno	2021-12-16 10:41:54 +00:00
gve_rx_dqo.c	gve: Implement packet continuation for RX.	2021-10-25 14:13:12 +01:00
gve_tx.c	gve: Add optional metadata descriptor type GVE_TXD_MTD	2021-12-16 10:41:54 +00:00
gve_tx_dqo.c	gve: DQO: avoid unused variable warnings	2021-09-28 15:24:36 +01:00
gve_utils.c	gve: fix for null pointer dereference.	2021-12-07 20:57:17 -08:00
gve_utils.h	gve: Implement packet continuation for RX.	2021-10-25 14:13:12 +01:00
Makefile	gve: DQO: Add core netdev features	2021-06-24 12:47:38 -07:00