[PATCH 1/2][SRU][B] i40e: Do not allow use more TC queue pairs than MSI-X vectors exist

[Nivedita Singhvi]

From: Paweł Jabłoński <pawel.jablonski at intel.com>

BugLink: https://bugs.launchpad.net/bugs/1820948

This patch suppresses the message about invalid TC mapping and wrong
selected TX queue. The root cause of this bug was setting too many
TC queue pairs on huge multiprocessor machines. When quantity of the
TC queue pairs is exceeding MSI-X vectors count then TX queue number
can be selected beyond actual TX queues amount.

Signed-off-by: Paweł Jabłoński <pawel.jablonski at intel.com>
Tested-by: Andrew Bowers <andrewx.bowers at intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher at intel.com>
(cherry-picked from commit 1563f2d2e01242f05dd523ffd56fe104bc1afd58)
Signed-off-by: Nivedita Singhvi <nivedita.singhvi at canonical.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 08f7bd9001bc..8ad1710804f6 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -1818,6 +1818,10 @@ static void i40e_vsi_setup_queue_map(struct i40e_vsi *vsi,
 	num_tc_qps = qcount / numtc;
 	num_tc_qps = min_t(int, num_tc_qps, i40e_pf_get_max_q_per_tc(pf));
 
+	/* Do not allow use more TC queue pairs than MSI-X vectors exist */
+	if (pf->flags & I40E_FLAG_MSIX_ENABLED)
+		num_tc_qps = min_t(int, num_tc_qps, pf->num_lan_msix);
+
 	/* Setup queue offset/count for all TCs for given VSI */
 	for (i = 0; i < I40E_MAX_TRAFFIC_CLASS; i++) {
 		/* See if the given TC is enabled for the given VSI */
-- 
2.17.1