[PATCH] doc: update mlxreg command arguments for recent versions

[Ali Alnubani]

Recent versions of the command require vhca_id and all_vhca
to be set with the --indexes arg.

Signed-off-by: Ali Alnubani <alialnu at nvidia.com>
---
 doc/guides/nics/mlx5.rst | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 7a137d5f6a..68ecdbec15 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -1887,9 +1887,15 @@ The procedure below is an example of using a ConnectX-5 adapter card (pf0) with
         $ ip link set p0 vf 0 trust on
         $ ip link set p0 vf 1 trust on
 
-#. Configure all VFs using mlxreg::
+#. Configure all VFs using mlxreg:
 
-   $ mlxreg -d /dev/mst/mt4121_pciconf0 --reg_name VHCA_TRUST_LEVEL --yes --set "all_vhca=0x1,trust_level=0x1"
+      - For MFT >= 4.21::
+
+        $ mlxreg -d /dev/mst/mt4121_pciconf0 --reg_name VHCA_TRUST_LEVEL --yes --indexes 'all_vhca=0x1,vhca_id=0x0' --set 'trust_level=0x1'
+
+      - For MFT < 4.21::
+
+        $ mlxreg -d /dev/mst/mt4121_pciconf0 --reg_name VHCA_TRUST_LEVEL --yes --set "all_vhca=0x1,trust_level=0x1"
 
    .. note::
 
-- 
2.25.1