[net-next,0/6] gve: Alloc before freeing when changing config

Message

Shailend Chand Jan. 22, 2024, 6:26 p.m. UTC

Functions allocating resources did so directly into priv thus far. The
assumption doing that was that priv was not already holding references
to live resources.

When ring configuration is changed in any way from userspace, thus far
we relied on calling the ndo_stop and ndo_open callbacks in succession.
This meant that we teardown existing resources and rob the OS of
networking before we have successfully allocated resources for the new
config.

Correcting this requires us to perform allocations without editing priv.
That is what the "gve: Switch to config-aware..." patch does: it modifies
all the allocation paths so that they take a new configuration as input
and return references to newly allocated resources without modifying
priv or interfering with live resources in any way.

Having corrected the allocation paths so, the ndo open and close
callbacks are refactored to make available distinct functions for
allocating queue resources and starting or stopping them. This is then
put to use in the set_channels and set_features hooks in the last two
patches.

These changes have been tested by verifying the integrity of a stream of
integers while the driver is continuously reconfigured with ethtool.

Shailend Chand (6):
  gve: Define config structs for queue allocation
  gve: Refactor napi add and remove functions
  gve: Switch to config-aware queue allocation
  gve: Refactor gve_open and gve_close
  gve: Alloc before freeing when adjusting queues
  gve: Alloc before freeing when changing features

 drivers/net/ethernet/google/gve/gve.h        | 144 +++-
 drivers/net/ethernet/google/gve/gve_dqo.h    |  18 +-
 drivers/net/ethernet/google/gve/gve_main.c   | 854 ++++++++++++-------
 drivers/net/ethernet/google/gve/gve_rx.c     | 116 ++-
 drivers/net/ethernet/google/gve/gve_rx_dqo.c |  91 +-
 drivers/net/ethernet/google/gve/gve_tx.c     | 128 ++-
 drivers/net/ethernet/google/gve/gve_tx_dqo.c | 108 ++-
 drivers/net/ethernet/google/gve/gve_utils.c  |  31 +
 drivers/net/ethernet/google/gve/gve_utils.h  |   5 +
 9 files changed, 999 insertions(+), 496 deletions(-)

Comments

[e-mail] Jan. 24, 2024, 1:50 a.m. UTC | #1

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <[e-mail]>:

On Mon, 22 Jan 2024 18:26:26 +0000 you wrote:
> Functions allocating resources did so directly into priv thus far. The
> assumption doing that was that priv was not already holding references
> to live resources.
> 
> When ring configuration is changed in any way from userspace, thus far
> we relied on calling the ndo_stop and ndo_open callbacks in succession.
> This meant that we teardown existing resources and rob the OS of
> networking before we have successfully allocated resources for the new
> config.
> 
> [...]

Here is the summary with links:
  - [net-next,1/6] gve: Define config structs for queue allocation
    https://git.kernel.org/netdev/net-next/c/7cea48b9a4b2
  - [net-next,2/6] gve: Refactor napi add and remove functions
    https://git.kernel.org/netdev/net-next/c/1dfc2e46117e
  - [net-next,3/6] gve: Switch to config-aware queue allocation
    https://git.kernel.org/netdev/net-next/c/f13697cc7a19
  - [net-next,4/6] gve: Refactor gve_open and gve_close
    https://git.kernel.org/netdev/net-next/c/92a6d7a4010c
  - [net-next,5/6] gve: Alloc before freeing when adjusting queues
    https://git.kernel.org/netdev/net-next/c/5f08cd3d6423
  - [net-next,6/6] gve: Alloc before freeing when changing features
    https://git.kernel.org/netdev/net-next/c/f3753771e7cc

You are awesome, thank you!