Merge branch 'gve-alloc-before-freeing-when-changing-config'

Shailend Chand says:

====================
gve: Alloc before freeing when changing config

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.
====================

Link: https://lore.kernel.org/r/20240122182632.1102721-1-shailend@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>