[dpdk-stable] [PATCH v2 2/2] vdpa/mlx5: fix large VM memory region registration

Xueming Li xuemingl at nvidia.com
Thu Sep 23 10:11:22 CEST 2021


When VM size larger than 4G(u32) and memory region larger than 4G, the
32 bits GCD function overflow and returned wrong value that resulted
memory registration failed.

This patch calls 64 bits GCD function to avoid overflow.

Fixes: cc07a42da250 ("vdpa/mlx5: prepare memory regions")
Cc: matan at mellanox.com
Cc: stable at dpdk.org
Reviewed-by: Matan Azrad <matan at nvidia.com>

Signed-off-by: Xueming Li <xuemingl at nvidia.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa_mem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_mem.c b/drivers/vdpa/mlx5/mlx5_vdpa_mem.c
index 59ce4e891c..a06681b494 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_mem.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_mem.c
@@ -103,15 +103,15 @@ mlx5_vdpa_vhost_mem_regions_prepare(int vid, uint8_t *mode, uint64_t *mem_size,
 			size = mem->regions[i].guest_phys_addr -
 				(mem->regions[i - 1].guest_phys_addr +
 				 mem->regions[i - 1].size);
-			*gcd = rte_get_gcd(*gcd, size);
+			*gcd = rte_get_gcd64(*gcd, size);
 			klm_entries_num += KLM_NUM_MAX_ALIGN(size);
 		}
 		size = mem->regions[i].size;
-		*gcd = rte_get_gcd(*gcd, size);
+		*gcd = rte_get_gcd64(*gcd, size);
 		klm_entries_num += KLM_NUM_MAX_ALIGN(size);
 	}
 	if (*gcd > MLX5_MAX_KLM_BYTE_COUNT)
-		*gcd = rte_get_gcd(*gcd, MLX5_MAX_KLM_BYTE_COUNT);
+		*gcd = rte_get_gcd64(*gcd, MLX5_MAX_KLM_BYTE_COUNT);
 	if (!RTE_IS_POWER_OF_2(*gcd)) {
 		uint64_t candidate_gcd = rte_align64prevpow2(*gcd);
 
-- 
2.33.0



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