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  1. Jan 31, 2020
    • Jason Gunthorpe's avatar
      RDMA/core: Make the entire API tree static · 8889f6fa
      Jason Gunthorpe authored 
      Compilation of mlx5 driver without CONFIG_INFINIBAND_USER_ACCESS generates
the following error.

on x86_64:

 ld: drivers/infiniband/hw/mlx5/main.o: in function `mlx5_ib_handler_MLX5_IB_METHOD_VAR_OBJ_ALLOC':
 main.c:(.text+0x186d): undefined reference to `ib_uverbs_get_ucontext_file'
 ld: drivers/infiniband/hw/mlx5/main.o:(.rodata+0x2480): undefined reference to `uverbs_idr_class'
 ld: drivers/infiniband/hw/mlx5/main.o:(.rodata+0x24d8): undefined reference to `uverbs_destroy_def_handler'

This is happening because some parts of the UAPI description are not
static. This is a hold over from earlier code that relied on struct
pointers to refer to object types, now object types are referenced by
number. Remove the unused globals and add statics to the remaining UAPI
description elements.

Remove the redundent #ifdefs around mlx5_ib_*defs and obsolete
mlx5_ib_get_devx_tree().

The compiler now trims alot more unused code, including the above
problematic definitions when !CONFIG_INFINIBAND_USER_ACCESS.

Fixes: 7be76bef

 ("IB/mlx5: Introduce VAR object and its alloc/destroy methods")
Reported-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Acked-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      8889f6fa
  3. Jan 30, 2020
  5. Jan 29, 2020
  7. Jan 28, 2020
    • Håkon Bugge's avatar
      IB/mlx4: Fix leak in id_map_find_del · ea660ad7
      Håkon Bugge authored 
      Using CX-3 virtual functions, either from a bare-metal machine or
pass-through from a VM, MAD packets are proxied through the PF driver.

Since the VF drivers have separate name spaces for MAD Transaction Ids
(TIDs), the PF driver has to re-map the TIDs and keep the book keeping in
a cache.

Following the RDMA Connection Manager (CM) protocol, it is clear when an
entry has to evicted from the cache. When a DREP is sent from
mlx4_ib_multiplex_cm_handler(), id_map_find_del() is called. Similar when
a REJ is received by the mlx4_ib_demux_cm_handler(), id_map_find_del() is
called.

This function wipes out the TID in use from the IDR or XArray and removes
the id_map_entry from the table.

In short, it does everything except the topping of the cake, which is to
remove the entry from the list and free it. In other words, for the REJ
case enumerated above, one id_map_entry will be leaked.

For the other case above, a DREQ has been received first. The reception of
the DREQ will trigger queuing of a delayed work to delete the
id_map_entry, for the case where the VM doesn't send back a DREP.

In the normal case, the VM _will_ send back a DREP, and id_map_find_del()
will be called.

But this scenario introduces a secondary leak. First, when the DREQ is
received, a delayed work is queued. The VM will then return a DREP, which
will call id_map_find_del(). As stated above, this will free the TID used
from the XArray or IDR. Now, there is window where that particular TID can
be re-allocated, lets say by an outgoing REQ. This TID will later be wiped
out by the delayed work, when the function id_map_ent_timeout() is
called. But the id_map_entry allocated by the outgoing REQ will not be
de-allocated, and we have a leak.

Both leaks are fixed by removing the id_map_find_del() function and only
using schedule_delayed(). Of course, a check in schedule_delayed() to see
if the work already has been queued, has been added.

Another benefit of always using the delayed version for deleting entries,
is that we do get a TimeWait effect; a TID no longer in use, will occupy
the XArray or IDR for CM_CLEANUP_CACHE_TIMEOUT time, without any ability
of being re-used for that time period.

Fixes: 3cf69cc8 ("IB/mlx4: Add CM paravirtualization")
Link: https://lore.kernel.org/r/20200123155521.1212288-1-haakon.bugge@oracle.com


Signed-off-by: default avatarHåkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: default avatarManjunath Patil <manjunath.b.patil@oracle.com>
Reviewed-by: default avatarRama Nichanamatlu <rama.nichanamatlu@oracle.com>
Reviewed-by: default avatarJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      ea660ad7
  9. Jan 26, 2020
  11. Jan 21, 2020
    • Jason Gunthorpe's avatar
      Merge tag 'rds-odp-for-5.5' into rdma.git for-next · e8b3a426
      Jason Gunthorpe authored 
      From https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma



Leon Romanovsky says:

====================
Use ODP MRs for kernel ULPs

The following series extends MR creation routines to allow creation of
user MRs through kernel ULPs as a proxy. The immediate use case is to
allow RDS to work over FS-DAX, which requires ODP (on-demand-paging)
MRs to be created and such MRs were not possible to create prior this
series.

The first part of this patchset extends RDMA to have special verb
ib_reg_user_mr(). The common use case that uses this function is a
userspace application that allocates memory for HCA access but the
responsibility to register the memory at the HCA is on an kernel ULP.
This ULP acts as an agent for the userspace application.

The second part provides advise MR functionality for ULPs. This is
integral part of ODP flows and used to trigger pagefaults in advance
to prepare memory before running working set.

The third part is actual user of those in-kernel APIs.
====================

* tag 'rds-odp-for-5.5':
  net/rds: Use prefetch for On-Demand-Paging MR
  net/rds: Handle ODP mr registration/unregistration
  net/rds: Detect need of On-Demand-Paging memory registration
  RDMA/mlx5: Fix handling of IOVA != user_va in ODP paths
  IB/mlx5: Mask out unsupported ODP capabilities for kernel QPs
  RDMA/mlx5: Don't fake udata for kernel path
  IB/mlx5: Add ODP WQE handlers for kernel QPs
  IB/core: Add interface to advise_mr for kernel users
  IB/core: Introduce ib_reg_user_mr
  IB: Allow calls to ib_umem_get from kernel ULPs

Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      e8b3a426
  13. Jan 18, 2020
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