Re: [PATCH rdma-rc 5/9] IB/mlx4: Handle well-known-gid in mad_demux processing

Hal Rosenstock
2016-11-05T21:03:25Z

On 11/5/2016 3:57 PM, Leon Romanovsky wrote:
> From: Jack Morgenstein <jackm-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
>
> If OpenSM runs over ConnectX-3, and there are ConnectIB VFs active
> on the network, the OpenSM will receive QP1 packets containing a GRH
> where the destination GID is the "Well-Known GID" -- which is not a GID
> in the HCA Port's GID Table.
>
> This GID must be tested-for separately -- and packets which contain
> this destination GID should be routed to slave 0 (the PF).
>
> Fixes: 37bfc7c1e83f ('IB/mlx4: SR-IOV multiplex and demultiplex MADs')
> Signed-off-by: Jack Morgenstein <jackm-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
> Signed-off-by: Daniel Jurgens <danielj-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> ---
> drivers/infiniband/hw/mlx4/mad.c | 16 ++++++++++++----
> include/rdma/ib_verbs.h | 1 +
> 2 files changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
> index b8e9013..f0b8272 100644
> --- a/drivers/infiniband/hw/mlx4/mad.c
> +++ b/drivers/infiniband/hw/mlx4/mad.c
> @@ -729,10 +729,18 @@ static int mlx4_ib_demux_mad(struct ib_device *ibdev, u8 port,
>
> /* If a grh is present, we demux according to it */
> if (wc->wc_flags & IB_WC_GRH) {
> - slave = mlx4_ib_find_real_gid(ibdev, port, grh->dgid.global.interface_id);
> - if (slave < 0) {
> - mlx4_ib_warn(ibdev, "failed matching grh\n");
> - return -ENOENT;
> + if (grh->dgid.global.interface_id ==
> + cpu_to_be64(IB_SA_WELL_KNOWN_GUID) &&
> + grh->dgid.global.subnet_prefix ==
> + cpu_to_be64(IB_SA_WELL_KNOWN_GID_PREFIX)) {
> + slave = 0;
> + } else {
> + slave = mlx4_ib_find_real_gid(ibdev, port,
> + grh->dgid.global.interface_id);
> + if (slave < 0) {
> + mlx4_ib_warn(ibdev, "failed matching grh\n");
> + return -ENOENT;
> + }
> }
> }
> /* Class-specific handling */
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index 467a4b4..da5949f 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -100,6 +100,7 @@ enum rdma_node_type {
>
> enum {
> /* set the local administered indication */
> + IB_SA_WELL_KNOWN_GID_PREFIX = 0xfe80000000000000ull,
> IB_SA_WELL_KNOWN_GUID = BIT_ULL(57) | 2,

Isn't the SA well-known GID the concatenation of the subnet prefix
(which isn't necessarily the default link local one) and the GUID
0x0200000000000002 ?

-- Hal

> };
>
>