vdpa/mlx5: Fix oversized null mkey longer than 32bit

commit a6097e0a54a5c24f8d577ffecbc35289ae281c2e upstream.

create_user_mr() has correct code to count the number of null keys
used to fill in a hole for the memory map. However, fill_indir()
does not follow the same to cap the range up to the 1GB limit
correspondingly. Fill in more null keys for the gaps in between,
so that null keys are correctly populated.

Fixes: 94abbccdf291 ("vdpa/mlx5: Add shared memory registration code")
Cc: stable@vger.kernel.org
Reported-by: Cong Meng <cong.meng@oracle.com>
Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20250220193732.521462-2-dtatulea@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index aa4ab4c847fdcc7996cbf10e23f9dd40cc2bd5f5..165730656934528df6e824e5f69a223d558bf7c4 100644 (file)
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -166,9 +166,12 @@ again:
                        klm->bcount = cpu_to_be32(klm_bcount(dmr->end - dmr->start));
                        preve = dmr->end;
                } else {
+                       u64 bcount = min_t(u64, dmr->start - preve, MAX_KLM_SIZE);
+
                        klm->key = cpu_to_be32(mvdev->res.null_mkey);
-                       klm->bcount = cpu_to_be32(klm_bcount(dmr->start - preve));
-                       preve = dmr->start;
+                       klm->bcount = cpu_to_be32(klm_bcount(bcount));
+                       preve += bcount;
+
                        goto again;
                }
        }