ice: always add legacy 32byte RXDID in supported_rxdids

When the PF and VF drivers both support flexible rx descriptors and have
negotiated the VIRTCHNL_VF_OFFLOAD_RX_FLEX_DESC capability, the VF driver
queries the PF for the list of supported descriptor formats
(VIRTCHNL_OP_GET_SUPPORTED_RXDIDS). The PF driver is supposed to set the
supported_rxdids bits that correspond to the descriptor formats the
firmware implements. The legacy 32-byte rx desc format is always
supported, even though it is not expressed in GLFLXP_RXDID_FLAGS.

The ice driver does not advertise the legacy 32-byte rx desc support,
which leads to this failure to bring up the VF using the Intel
out-of-tree iavf driver:
 iavf 0000:41:01.0: PF does not list support for default Rx descriptor format
 ...
 iavf 0000:41:01.0: PF returned error -5 (VIRTCHNL_STATUS_ERR_PARAM) to our request 6

The in-tree iavf driver does not expose this bug, because it does not
yet implement VIRTCHNL_VF_OFFLOAD_RX_FLEX_DESC.

The ice driver must always set the ICE_RXDID_LEGACY_1 bit in
supported_rxdids. The Intel out-of-tree ice driver and the ice driver in
DPDK both do this.

I copied this piece of the code and the comment text from the Intel
out-of-tree driver.

Fixes: e753df8fbca5 ("ice: Add support Flex RXD")
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Link: https://lore.kernel.org/r/20230920115439.61172-1-mschmidt@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl.c b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
index b03426a..db97353 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
@@ -2617,12 +2617,14 @@ static int ice_vc_query_rxdid(struct ice_vf *vf)
                goto err;
        }
 
-       /* Read flexiflag registers to determine whether the
-        * corresponding RXDID is configured and supported or not.
-        * Since Legacy 16byte descriptor format is not supported,
-        * start from Legacy 32byte descriptor.
+       /* RXDIDs supported by DDP package can be read from the register
+        * to get the supported RXDID bitmap. But the legacy 32byte RXDID
+        * is not listed in DDP package, add it in the bitmap manually.
+        * Legacy 16byte descriptor is not supported.
         */
-       for (i = ICE_RXDID_LEGACY_1; i < ICE_FLEX_DESC_RXDID_MAX_NUM; i++) {
+       rxdid->supported_rxdids |= BIT(ICE_RXDID_LEGACY_1);
+
+       for (i = ICE_RXDID_FLEX_NIC; i < ICE_FLEX_DESC_RXDID_MAX_NUM; i++) {
                regval = rd32(hw, GLFLXP_RXDID_FLAGS(i, 0));
                if ((regval >> GLFLXP_RXDID_FLAGS_FLEXIFLAG_4N_S)
                        & GLFLXP_RXDID_FLAGS_FLEXIFLAG_4N_M)