[PATCH net-next] ice: fix broken Rx on VFs

[Alexander Lobakin <aleksander.lobakin@intel.com>]

Since the tagged commit, ice stopped respecting Rx buffer length
passed from VFs.
At that point, the buffer length was hardcoded in ice, so VFs still
worked up to some point (until, for example, a VF wanted an MTU
larger than its PF).
The next commit 93f53db9f9dc ("ice: switch to Page Pool"), broke
Rx on VFs completely since ice started accounting per-queue buffer
lengths again, but now VF queues always had their length zeroed, as
ice was already ignoring what iavf was passing to it.

Restore the line that initializes the buffer length on VF queues
basing on the virtchnl messages.

Fixes: 3a4f419f7509 ("ice: drop page splitting and recycling")
Reported-by: Jakub Slepecki <jakub.slepecki@intel.com>
Reviewed-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
I'd like this to go directly to net-next to quickly unbreak VFs
(the related commits are not in the mainline yet).
---
 drivers/net/ethernet/intel/ice/virt/queues.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/virt/queues.c b/drivers/net/ethernet/intel/ice/virt/queues.c
index 7928f4e8e788..f73d5a3e83d4 100644
--- a/drivers/net/ethernet/intel/ice/virt/queues.c
+++ b/drivers/net/ethernet/intel/ice/virt/queues.c
@@ -842,6 +842,9 @@ int ice_vc_cfg_qs_msg(struct ice_vf *vf, u8 *msg)
 			    (qpi->rxq.databuffer_size > ((16 * 1024) - 128) ||
 			     qpi->rxq.databuffer_size < 1024))
 				goto error_param;
+
+			ring->rx_buf_len = qpi->rxq.databuffer_size;
+
 			if (qpi->rxq.max_pkt_size > max_frame_size ||
 			    qpi->rxq.max_pkt_size < 64)
 				goto error_param;
-- 
2.51.1