mm: replace get_user_pages_remote() write/force parameters with gup_flags

This removes the 'write' and 'force' from get_user_pages_remote() and
replaces them with 'gup_flags' to make the use of FOLL

mm: replace get_user_pages_remote() write/force parameters with gup_flags

This removes the 'write' and 'force' from get_user_pages_remote() and
replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in
callers as use of this flag can result in surprising behaviour (and
hence bugs) within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

mm/gup: Introduce get_user_pages_remote()

For protection keys, we need to understand whether protections
should be enforced in software or not. In general, we enforce
protections when working on ou

mm/gup: Introduce get_user_pages_remote()

For protection keys, we need to understand whether protections
should be enforced in software or not. In general, we enforce
protections when working on our own task, but not when on others.
We call these "current" and "remote" operations.

This patch introduces a new get_user_pages() variant:

get_user_pages_remote()

Which is a replacement for when get_user_pages() is called on
non-current tsk/mm.

We also introduce a new gup flag: FOLL_REMOTE which can be used
for the "__" gup variants to get this new behavior.

The uprobes is_trap_at_addr() location holds mmap_sem and
calls get_user_pages(current->mm) on an instruction address. This
makes it a pretty unique gup caller. Being an instruction access
and also really originating from the kernel (vs. the app), I opted
to consider this a 'remote' access where protection keys will not
be enforced.

Without protection keys, this patch should not change any behavior.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: jack@suse.cz
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210154.3F0E51EA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

IB/core: constify mmu_notifier_ops structures

This mmu_notifier_ops structure is never modified, so declare it as
const, like the other mmu_notifier_ops structures.

Done with the help of Coccinelle

IB/core: constify mmu_notifier_ops structures

This mmu_notifier_ops structure is never modified, so declare it as
const, like the other mmu_notifier_ops structures.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

show more ...

IB/core: dma unmap optimizations

While unmapping an ODP writable page, the dirty bit of the page is set. In
order to do so, the head of the compound page is found.
Currently, the compound head is fo

IB/core: dma unmap optimizations

While unmapping an ODP writable page, the dirty bit of the page is set. In
order to do so, the head of the compound page is found.
Currently, the compound head is found even on non-writable pages, where it is
never used, leading to unnecessary cpu barrier that impacts performance.

This patch moves the search for the compound head to be done only when needed.

Signed-off-by: Guy Shapiro <guysh@mellanox.com>
Acked-by: Shachar Raindel <raindel@mellanox.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

show more ...

IB/core: dma map/unmap locking optimizations

Currently, while mapping or unmapping pages for ODP, the umem mutex is locked
and unlocked once for each page. Such lock/unlock operation take few tens t

IB/core: dma map/unmap locking optimizations

Currently, while mapping or unmapping pages for ODP, the umem mutex is locked
and unlocked once for each page. Such lock/unlock operation take few tens to
hundreds of nsecs. This makes a significant impact when mapping or unmapping few
MBs of memory.

To avoid this, the mutex should be locked only once per operation, and not per
page.

Signed-off-by: Guy Shapiro <guysh@mellanox.com>
Acked-by: Shachar Raindel <raindel@mellanox.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

show more ...

IB/core: Properly handle registration of on-demand paging MRs after dereg

When the last on-demand paging MR is released the notifier count is
left non-zero so that concurrent page faults will have t

IB/core: Properly handle registration of on-demand paging MRs after dereg

When the last on-demand paging MR is released the notifier count is
left non-zero so that concurrent page faults will have to abort. If a
new MR is then registered, the counter is reset. However, the decision
is made to put the new MR in the list waiting for the notifier count
to reach zero, before the counter is reset. An invalidation or another
MR registration can release the MR to handle page faults, but without
such an event the MR can wait forever.

The patch fixes this issue by adding a check whether the MR is the
first on-demand paging MR when deciding whether it is ready to handle
page faults. If it is the first MR, we know that there are no mmu
notifiers running in parallel to the registration.

Fixes: 882214e2b128 ("IB/core: Implement support for MMU notifiers regarding on demand paging regions")
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

show more ...

IB/core: Implement support for MMU notifiers regarding on demand paging regions

* Add an interval tree implementation for ODP umems. Create an
interval tree for each ucontext (including a count of

IB/core: Implement support for MMU notifiers regarding on demand paging regions

* Add an interval tree implementation for ODP umems. Create an
interval tree for each ucontext (including a count of the number of
ODP MRs in this context, semaphore, etc.), and register ODP umems in
the interval tree.
* Add MMU notifiers handling functions, using the interval tree to
notify only the relevant umems and underlying MRs.
* Register to receive MMU notifier events from the MM subsystem upon
ODP MR registration (and unregister accordingly).
* Add a completion object to synchronize the destruction of ODP umems.
* Add mechanism to abort page faults when there's a concurrent invalidation.

The way we synchronize between concurrent invalidations and page
faults is by keeping a counter of currently running invalidations, and
a sequence number that is incremented whenever an invalidation is
caught. The page fault code checks the counter and also verifies that
the sequence number hasn't progressed before it updates the umem's
page tables. This is similar to what the kvm module does.

In order to prevent the case where we register a umem in the middle of
an ongoing notifier, we also keep a per ucontext counter of the total
number of active mmu notifiers. We only enable new umems when all the
running notifiers complete.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Yuval Dagan <yuvalda@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

show more ...

IB/core: Add support for on demand paging regions

* Extend the umem struct to keep the ODP related data.
* Allocate and initialize the ODP related information in the umem
(page_list, dma_list) and

IB/core: Add support for on demand paging regions

* Extend the umem struct to keep the ODP related data.
* Allocate and initialize the ODP related information in the umem
(page_list, dma_list) and freeing as needed in the end of the run.
* Store a reference to the process PID struct in the ucontext. Used to
safely obtain the task_struct and the mm during fault handling,
without preventing the task destruction if needed.
* Add 2 helper functions: ib_umem_odp_map_dma_pages and
ib_umem_odp_unmap_dma_pages. These functions get the DMA addresses
of specific pages of the umem (and, currently, pin them).
* Support for page faults only - IB core will keep the reference on
the pages used and call put_page when freeing an ODP umem
area. Invalidations support will be added in a later patch.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

show more ...

IB/core: Enable ODP sync without faulting

Enable ODP sync without faulting, this improves performance by reducing
the number of page faults in the system.

The gain from this opt

IB/core: Enable ODP sync without faulting

Enable ODP sync without faulting, this improves performance by reducing
the number of page faults in the system.

The gain from this option is that the device page table can be aligned
with the presented pages in the CPU page table without causing page
faults.

As of that, the overhead on data path from hardware point of view to
trigger a fault which end-up by calling the driver to bring the pages
will be dropped.

Link: https://lore.kernel.org/r/20200930163828.1336747-3-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

show more ...

IB/core: Improve ODP to use hmm_range_fault()

Move to use hmm_range_fault() instead of get_user_pags_remote() to improve
performance in a few aspects:

This includes:
- Dropp

IB/core: Improve ODP to use hmm_range_fault()

Move to use hmm_range_fault() instead of get_user_pags_remote() to improve
performance in a few aspects:

This includes:
- Dropping the need to allocate and free memory to hold its output

- No need any more to use put_page() to unpin the pages

- The logic to detect contiguous pages is done based on the returned
order, no need to run per page and evaluate.

In addition, moving to use hmm_range_fault() enables to reduce page faults
in the system with it's snapshot mode, this will be introduced in next
patches from this series.

As part of this, cleanup some flows and use the required data structures
to work with hmm_range_fault().

Link: https://lore.kernel.org/r/20200930163828.1336747-2-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

show more ...

mm/gup: remove task_struct pointer for all gup code

After the cleanup of page fault accounting, gup does not need to pass
task_struct around any more. Remove that parameter in the whole

mm/gup: remove task_struct pointer for all gup code

After the cleanup of page fault accounting, gup does not need to pass
task_struct around any more. Remove that parameter in the whole gup
stack.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

RDMA: Correct trivial kernel-doc inconsistencies

Silence documentation build warnings by correcting kernel-doc comments.

./drivers/infiniband/core/verbs.c:1004: warning: Function pa

RDMA: Correct trivial kernel-doc inconsistencies

Silence documentation build warnings by correcting kernel-doc comments.

./drivers/infiniband/core/verbs.c:1004: warning: Function parameter or member 'uobject' not described in 'ib_create_srq_user'
./drivers/infiniband/core/verbs.c:1004: warning: Function parameter or member 'udata' not described in 'ib_create_srq_user'
./drivers/infiniband/core/umem_odp.c:161: warning: Function parameter or member 'ops' not described in 'ib_umem_odp_alloc_child'
./drivers/infiniband/core/umem_odp.c:225: warning: Function parameter or member 'ops' not described in 'ib_umem_odp_get'
./drivers/infiniband/sw/rdmavt/ah.c:104: warning: Excess function parameter 'ah_attr' description in 'rvt_create_ah'
./drivers/infiniband/sw/rdmavt/ah.c:104: warning: Excess function parameter 'create_flags' description in 'rvt_create_ah'
./drivers/infiniband/ulp/iser/iscsi_iser.h:363: warning: Function parameter or member 'all_list' not described in 'iser_fr_desc'
./drivers/infiniband/ulp/iser/iscsi_iser.h:377: warning: Function parameter or member 'all_list' not described in 'iser_fr_pool'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:148: warning: Function parameter or member 'rsvd0' not described in 'opa_vesw_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:148: warning: Function parameter or member 'rsvd1' not described in 'opa_vesw_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:148: warning: Function parameter or member 'rsvd2' not described in 'opa_vesw_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:148: warning: Function parameter or member 'rsvd3' not described in 'opa_vesw_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:148: warning: Function parameter or member 'rsvd4' not described in 'opa_vesw_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:205: warning: Function parameter or member 'rsvd0' not described in 'opa_per_veswport_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:205: warning: Function parameter or member 'rsvd1' not described in 'opa_per_veswport_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:205: warning: Function parameter or member 'rsvd2' not described in 'opa_per_veswport_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:205: warning: Function parameter or member 'rsvd3' not described in 'opa_per_veswport_info'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:342: warning: Function parameter or member 'reserved' not described in 'opa_veswport_summary_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd0' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd1' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd2' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd3' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd4' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd5' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd6' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd7' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd8' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:394: warning: Function parameter or member 'rsvd9' not described in 'opa_veswport_error_counters'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:460: warning: Function parameter or member 'reserved' not described in 'opa_vnic_vema_mad'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:485: warning: Function parameter or member 'reserved' not described in 'opa_vnic_notice_attr'
./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:500: warning: Function parameter or member 'reserved' not described in 'opa_vnic_vema_mad_trap'

Link: https://lore.kernel.org/r/5373936.DvuYhMxLoT@laptop.coltonlewis.name
Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

RDMA/odp: Fix leaking the tgid for implicit ODP

The tgid used to be part of ib_umem_free_notifier(), when it was reworked
it got moved to release, but it should have been unconditional a

RDMA/odp: Fix leaking the tgid for implicit ODP

The tgid used to be part of ib_umem_free_notifier(), when it was reworked
it got moved to release, but it should have been unconditional as all umem
alloc paths get the tgid.

As is, creating an implicit ODP will leak the tgid reference.

Link: https://lore.kernel.org/r/20200304181607.GA22412@ziepe.ca
Cc: stable@kernel.org
Fixes: f25a546e6529 ("RDMA/odp: Use mmu_interval_notifier_insert()")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

RDMA/odp: Ensure the mm is still alive before creating an implicit child

Registration of a mmu_notifier requires the caller to hold a mmget() on
the mm as registration is not permitted t

RDMA/odp: Ensure the mm is still alive before creating an implicit child

Registration of a mmu_notifier requires the caller to hold a mmget() on
the mm as registration is not permitted to race with exit_mmap(). There is
a BUG_ON inside the mmu_notifier to guard against this.

Normally creating a umem is done against current which implicitly holds
the mmget(), however an implicit ODP child is created from a pagefault
work queue and is not guaranteed to have a mmget().

Call mmget() around this registration and abort faulting if the MM has
gone to exit_mmap().

Before the patch below the notifier was registered when the implicit ODP
parent was created, so there was no chance to register a notifier outside
of current.

Fixes: c571feca2dc9 ("RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'")
Link: https://lore.kernel.org/r/20200227114118.94736-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull rdma updates from Jason Gunthorpe:
"A very quiet cycle with few notable changes. Mostly the usual l

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull rdma updates from Jason Gunthorpe:
"A very quiet cycle with few notable changes. Mostly the usual list of
one or two patches to drivers changing something that isn't quite rc
worthy. The subsystem seems to be seeing a larger number of rework and
cleanup style patches right now, I feel that several vendors are
prepping their drivers for new silicon.

Summary:

- Driver updates and cleanup for qedr, bnxt_re, hns, siw, mlx5, mlx4,
rxe, i40iw

- Larger series doing cleanup and rework for hns and hfi1.

- Some general reworking of the CM code to make it a little more
understandable

- Unify the different code paths connected to the uverbs FD scheme

- New UAPI ioctls conversions for get context and get async fd

- Trace points for CQ and CM portions of the RDMA stack

- mlx5 driver support for virtio-net formatted rings as RDMA raw
ethernet QPs

- verbs support for setting the PCI-E relaxed ordering bit on DMA
traffic connected to a MR

- A couple of bug fixes that came too late to make rc7"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (108 commits)
RDMA/core: Make the entire API tree static
RDMA/efa: Mask access flags with the correct optional range
RDMA/cma: Fix unbalanced cm_id reference count during address resolve
RDMA/umem: Fix ib_umem_find_best_pgsz()
IB/mlx4: Fix leak in id_map_find_del
IB/opa_vnic: Spelling correction of 'erorr' to 'error'
IB/hfi1: Fix logical condition in msix_request_irq
RDMA/cm: Remove CM message structs
RDMA/cm: Use IBA functions for complex structure members
RDMA/cm: Use IBA functions for simple structure members
RDMA/cm: Use IBA functions for swapping get/set acessors
RDMA/cm: Use IBA functions for simple get/set acessors
RDMA/cm: Add SET/GET implementations to hide IBA wire format
RDMA/cm: Add accessors for CM_REQ transport_type
IB/mlx5: Return the administrative GUID if exists
RDMA/core: Ensure that rdma_user_mmap_entry_remove() is a fence
IB/mlx4: Fix memory leak in add_gid error flow
IB/mlx5: Expose RoCE accelerator counters
RDMA/mlx5: Set relaxed ordering when requested
RDMA/core: Add the core support field to METHOD_GET_CONTEXT
...

show more ...

IB/{core,hw,umem}: set FOLL_PIN via pin_user_pages*(), fix up ODP

Convert infiniband to use the new pin_user_pages*() calls.

Also, revert earlier changes to Infiniband ODP that had

IB/{core,hw,umem}: set FOLL_PIN via pin_user_pages*(), fix up ODP

Convert infiniband to use the new pin_user_pages*() calls.

Also, revert earlier changes to Infiniband ODP that had it using
put_user_page(). ODP is "Case 3" in
Documentation/core-api/pin_user_pages.rst, which is to say, normal
get_user_pages() and put_page() is the API to use there.

The new pin_user_pages*() calls replace corresponding get_user_pages*()
calls, and set the FOLL_PIN flag. The FOLL_PIN flag requires that the
caller must return the pages via put_user_page*() calls, but infiniband
was already doing that as part of an earlier commit.

Link: http://lkml.kernel.org/r/20200107224558.2362728-14-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Merge tag 'rds-odp-for-5.5' into rdma.git for-next

From https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma

Leon Romanovsky says:

====================
Use O

Merge tag 'rds-odp-for-5.5' into rdma.git for-next

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: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB: Allow calls to ib_umem_get from kernel ULPs

So far the assumption was that ib_umem_get() and ib_umem_odp_get()
are called from flows that start in UVERBS and therefore has a user

IB: Allow calls to ib_umem_get from kernel ULPs

So far the assumption was that ib_umem_get() and ib_umem_odp_get()
are called from flows that start in UVERBS and therefore has a user
context. This assumption restricts flows that are initiated by ULPs
and need the service that ib_umem_get() provides.

This patch changes ib_umem_get() and ib_umem_odp_get() to get IB device
directly by relying on the fact that both UVERBS and ULPs sets that
field correctly.

Reviewed-by: Guy Levi <guyle@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

show more ...

IB/core: Fix build failure without hugepages

HPAGE_SHIFT is only defined on architectures that support hugepages:

drivers/infiniband/core/umem_odp.c: In function 'ib_umem_odp_get':

IB/core: Fix build failure without hugepages

HPAGE_SHIFT is only defined on architectures that support hugepages:

drivers/infiniband/core/umem_odp.c: In function 'ib_umem_odp_get':
drivers/infiniband/core/umem_odp.c:245:26: error: 'HPAGE_SHIFT' undeclared (first use in this function); did you mean 'PAGE_SHIFT'?

Enclose this in an #ifdef.

Fixes: 9ff1b6466a29 ("IB/core: Fix ODP with IB_ACCESS_HUGETLB handling")
Link: https://lore.kernel.org/r/20200109084740.2872079-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/core: Fix ODP with IB_ACCESS_HUGETLB handling

As VMAs for a given range might not be available as part of the
registration phase in ODP.

ib_init_umem_odp() considered the exp

IB/core: Fix ODP with IB_ACCESS_HUGETLB handling

As VMAs for a given range might not be available as part of the
registration phase in ODP.

ib_init_umem_odp() considered the expected page shift value that was
previously set and initializes its internals accordingly.

If memory isn't backed by physical contiguous pages aligned to a hugepage
boundary an error will be set as part of the page fault flow and come back
to the user as some failed RDMA operation.

Fixes: 0008b84ea9af ("IB/umem: Add support to huge ODP")
Link: https://lore.kernel.org/r/20191222124649.52300-4-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/core: Fix ODP get user pages flow

The nr_pages argument of get_user_pages_remote() should always be in terms
of the system page size, not the MR page size. Use PAGE_SIZE instead of

IB/core: Fix ODP get user pages flow

The nr_pages argument of get_user_pages_remote() should always be in terms
of the system page size, not the MR page size. Use PAGE_SIZE instead of
umem_odp->page_shift.

Fixes: 403cd12e2cf7 ("IB/umem: Add contiguous ODP support")
Link: https://lore.kernel.org/r/20191222124649.52300-3-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

RDMA/odp: Use mmu_interval_notifier_insert()

Replace the internal interval tree based mmu notifier with the new common
mmu_interval_notifier_insert() API. This removes a lot of code and

RDMA/odp: Use mmu_interval_notifier_insert()

Replace the internal interval tree based mmu notifier with the new common
mmu_interval_notifier_insert() API. This removes a lot of code and fixes a
deadlock that can be triggered in ODP:

zap_page_range()
mmu_notifier_invalidate_range_start()
[..]
ib_umem_notifier_invalidate_range_start()
down_read(&per_mm->umem_rwsem)
unmap_single_vma()
[..]
__split_huge_page_pmd()
mmu_notifier_invalidate_range_start()
[..]
ib_umem_notifier_invalidate_range_start()
down_read(&per_mm->umem_rwsem) // DEADLOCK

mmu_notifier_invalidate_range_end()
up_read(&per_mm->umem_rwsem)
mmu_notifier_invalidate_range_end()
up_read(&per_mm->umem_rwsem)

The umem_rwsem is held across the range_start/end as the ODP algorithm for
invalidate_range_end cannot tolerate changes to the interval
tree. However, due to the nested invalidation regions the second
down_read() can deadlock if there are competing writers. The new core code
provides an alternative scheme to solve this problem.

Fixes: ca748c39ea3f ("RDMA/umem: Get rid of per_mm->notifier_count")
Link: https://lore.kernel.org/r/20191112202231.3856-6-jgg@ziepe.ca
Tested-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

RDMA/odp: Remove broken debugging call to invalidate_range

invalidate_range() also obtains the umem_mutex which is being held at this
point, so if this path were was ever called it would

RDMA/odp: Remove broken debugging call to invalidate_range

invalidate_range() also obtains the umem_mutex which is being held at this
point, so if this path were was ever called it would deadlock. Thus
conclude the debugging never triggers and rework it into a simple WARN_ON
and leave things as they are.

While here add a note to explain how we could possibly get inconsistent
page pointers.

Link: https://lore.kernel.org/r/20191009160934.3143-16-jgg@ziepe.ca
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

RDMA/odp: Lift umem_mutex out of ib_umem_odp_unmap_dma_pages()

This fixes a race of the form:
CPU0 CPU1
mlx5_ib_invalidate_range() mlx5_ib_inval

RDMA/odp: Lift umem_mutex out of ib_umem_odp_unmap_dma_pages()

This fixes a race of the form:
CPU0 CPU1
mlx5_ib_invalidate_range() mlx5_ib_invalidate_range()
// This one actually makes npages == 0
ib_umem_odp_unmap_dma_pages()
if (npages == 0 && !dying)
// This one does nothing
ib_umem_odp_unmap_dma_pages()
if (npages == 0 && !dying)
dying = 1;
dying = 1;
schedule_work(&umem_odp->work);
// Double schedule of the same work
schedule_work(&umem_odp->work); // BOOM

npages and dying must be read and written under the umem_mutex lock.

Since whenever ib_umem_odp_unmap_dma_pages() is called mlx5 must also call
mlx5_ib_update_xlt, and both need to be done in the same locking region,
hoist the lock out of unmap.

This avoids an expensive double critical section in
mlx5_ib_invalidate_range().

Fixes: 81713d3788d2 ("IB/mlx5: Add implicit MR support")
Link: https://lore.kernel.org/r/20191001153821.23621-4-jgg@ziepe.ca
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...