i40e: Fix removing driver while bare-metal VFs pass traffic

stable inclusion
from linux-4.19.162
commit 71d97c0f61e198022e599520cf3896504e74d7cc

--------------------------------

[ Upstream commit 2980cbd4 ]

Prevent VFs from resetting when PF driver is being unloaded:
- introduce new pf state: __I40E_VF_RESETS_DISABLED;
- check if pf state has __I40E_VF_RESETS_DISABLED state set,
  if so, disable any further VFLR event notifications;
- when i40e_remove (rmmod i40e) is called, disable any resets on
  the VFs;

Previously if there were bare-metal VFs passing traffic and PF
driver was removed, there was a possibility of VFs triggering a Tx
timeout right before iavf_remove. This was causing iavf_close to
not be called because there is a check in the beginning of  iavf_remove
that bails out early if adapter->state < IAVF_DOWN_PENDING. This
makes it so some resources do not get cleaned up.

Fixes: 6a9ddb36 ("i40e: disable IOV before freeing resources")
Signed-off-by: Slawomir Laba <slawomirx.laba@intel.com>
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20201120180640.3654474-1-anthony.l.nguyen@intel.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Conflicts:
  drivers/net/ethernet/intel/i40e/i40e.h
[yyl: adjust context]
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

Signed-off-by: Aichun Li <liaichun@huawei.com>
reviewed-by: wangxiaopeng <wangxiaopeng7@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>