doc: add known VF issue when PF is reset

Add a known issue to warn that PF reset event/request is not
handled by any VF drivers till 2.2, and which should be fixed
in the future.

Reported-by: David Marchand <david.marchand@6wind.com>
Signed-off-by: Helin Zhang <helin.zhang@intel.com>

diff --git a/doc/guides/rel_notes/release_2_2.rst b/doc/guides/rel_notes/release_2_2.rst
index dedf503..c0f3be2 100644 (file)
--- a/doc/guides/rel_notes/release_2_2.rst
+++ b/doc/guides/rel_notes/release_2_2.rst
@@ -450,6 +450,11 @@ Known Issues
   As the l3fwd example application requires this info, the i40e vector
   driver must be disabled to benefit of the packet type with i40e.
 
+* Some (possibly all) VF drivers (e.g. i40evf) do not handle any PF reset
+  events/requests in VF driver, that means VF driver may not work after a
+  PF reset in host side. The workaround is to avoid triggering any PF reset
+  events/requests on host side.
+
 * **Mellanox PMDs (mlx4 & mlx5):**
 
   * PMDs do not support DPDK integrated shared library.