Patch "net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-mlx4_core-enable-4k-uar-if-sriov-module-parameter-is-not-enabled.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Huy Nguyen <[email protected]>
Date: Thu, 17 Aug 2017 18:29:52 +0300
Subject: net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled

From: Huy Nguyen <[email protected]>

[ Upstream commit ca3d89a3ebe79367bd41b6b8ba37664478ae2dba ]

enable_4k_uar module parameter was added in patch cited below to address the backward compatibility issue in SRIOV when the VM has system's PAGE_SIZE uar implementation and the Hypervisor has 4k uar implementation.

The above compatibility issue does not exist in the non SRIOV case. In this patch, we always enable 4k uar implementation if SRIOV is not enabled on mlx4's supported cards.

---
 drivers/net/ethernet/mellanox/mlx4/main.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -430,7 +430,7 @@ static int mlx4_dev_cap(struct mlx4_dev
 		/* Virtual PCI function needs to determine UAR page size from
 		 * firmware. Only master PCI function can set the uar page size
 		 */
-		if (enable_4k_uar)
+		if (enable_4k_uar || !dev->persist->num_vfs)
 			dev->uar_page_shift = DEFAULT_UAR_PAGE_SHIFT;
 		else
 			dev->uar_page_shift = PAGE_SHIFT;

@@ -2269,7 +2269,7 @@ static int mlx4_init_hca(struct mlx4_dev
 
 		dev->caps.max_fmr_maps = (1 << (32 - ilog2(dev->caps.num_mpts))) - 1;
 
-		if (enable_4k_uar) {
+		if (enable_4k_uar || !dev->persist->num_vfs) {
 			init_hca.log_uar_sz = ilog2(dev->caps.num_uars) +
 						    PAGE_SHIFT - DEFAULT_UAR_PAGE_SHIFT;
 			init_hca.uar_page_sz = DEFAULT_UAR_PAGE_SHIFT - 12;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/net-mlx4_core-enable-4k-uar-if-sriov-module-parameter-is-not-enabled.patch