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* [PATCH v13 0/4] RDMA: Add dma-buf support
@ 2020-12-07 22:15 ` Jianxin Xiong
  0 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Jianxin Xiong, Doug Ledford, Jason Gunthorpe, Leon Romanovsky,
	Sumit Semwal, Christian Koenig, Daniel Vetter

This is the thirteenth version of the patch set. Changelog:

v13:
* Rebase to the latest linux-rdma 'for-next' branch (5.10.0-rc6+)
* Check for device on-demand paging capability at the entry point of
  the new verbs command to avoid calling device's reg_user_mr_dmabuf()
  method when CONFIG_INFINIBAND_ON_DEMAND_PAGING is diabled.

v12: https://www.spinics.net/lists/linux-rdma/msg97943.html
* Move the prototype of function ib_umem_dmabuf_release() to ib_umem.h
  and remove umem_dmabuf.h
* Break a line that is too long

v11: https://www.spinics.net/lists/linux-rdma/msg97860.html
* Rework the parameter checking code inside ib_umem_dmabuf_get() 
* Fix incorrect error handling in the new verbs command handler
* Put a duplicated code sequence for checking iova and setting page size
  into a function
* In the invalidation callback, check for if the buffer has been mapped
  and thus the presence of a valid driver mr is ensured
* The patch that checks for dma_virt_ops is dropped because it is no
  longer needed
* The patch that documents that dma-buf size is fixed has landed at:
  https://cgit.freedesktop.org/drm/drm-misc/commit/?id=476b485be03c
  and thus is no longer included here
* The matching user space patch set is sent separately

v10: https://www.spinics.net/lists/linux-rdma/msg97483.html
* Don't map the pages in ib_umem_dmabuf_get(); use the size information
  of the dma-buf object to validate the umem size instead
* Use PAGE_SIZE directly instead of use ib_umem_find_best_pgsz() when
  the MR is created since the pages have not been mapped yet and dma-buf
  requires PAGE_SIZE anyway
* Always call mlx5_umem_find_best_pgsz() after mapping the pages to
  verify that the page size requirement is satisfied
* Add a patch to document that dma-buf size is fixed

v9: https://www.spinics.net/lists/linux-rdma/msg97432.html
* Clean up the code for sg list in-place modification
* Prevent dma-buf pages from being mapped multiple times
* Map the pages in ib_umem_dmabuf_get() so that inproper values of
  address/length/iova can be caught early
* Check for unsupported flags in the new uverbs command
* Add missing uverbs_finalize_uobj_create()
* Sort uverbs objects by name
* Fix formating issue -- unnecessary alignment of '='
* Unmap pages in mlx5_ib_fence_dmabuf_mr()
* Remove address range checking from pagefault_dmabuf_mr()

v8: https://www.spinics.net/lists/linux-rdma/msg97370.html
* Modify the dma-buf sg list in place to get a proper umem sg list and
  restore it before calling dma_buf_unmap_attachment()
* Validate the umem sg list with ib_umem_find_best_pgsz()
* Remove the logic for slicing the sg list at runtime

v7: https://www.spinics.net/lists/linux-rdma/msg97297.html
* Rebase on top of latest mlx5 MR patch series
* Slice dma-buf sg list at runtime instead of creating a new list
* Preload the buffer page mapping when the MR is created
* Move the 'dma_virt_ops' check into dma_buf_dynamic_attach()

v6: https://www.spinics.net/lists/linux-rdma/msg96923.html
* Move the dma-buf invalidation callback from the core to the device
  driver
* Move mapping update from work queue to pagefault handler
* Add dma-buf based MRs to the xarray of mmkeys so that the pagefault
  handler can be reached
* Update the new driver method and uverbs command signature by changing
  the paramter 'addr' to 'offset'
* Modify the sg list returned from dma_buf_map_attachment() based on
  the parameters 'offset' and 'length'
* Don't import dma-buf if 'dma_virt_ops' is used by the dma device
* The patch that clarifies dma-buf sg lists alignment has landed at
  https://cgit.freedesktop.org/drm/drm-misc/commit/?id=ac80cd17a615
  and thus is no longer included with this set

v5: https://www.spinics.net/lists/linux-rdma/msg96786.html
* Fix a few warnings reported by kernel test robot:
    - no previous prototype for function 'ib_umem_dmabuf_release' 
    - no previous prototype for function 'ib_umem_dmabuf_map_pages'
    - comparison of distinct pointer types in 'check_add_overflow'
* Add comment for the wait between getting the dma-buf sg tagle and
  updating the NIC page table

v4: https://www.spinics.net/lists/linux-rdma/msg96767.html
* Add a new ib_device method reg_user_mr_dmabuf() instead of expanding
  the existing method reg_user_mr()
* Use a separate code flow for dma-buf instead of adding special cases
  to the ODP memory region code path
* In invalidation callback, new mapping is updated as whole using work
  queue instead of being updated in page granularity in the page fault
  handler
* Use dma_resv_get_excl() and dma_fence_wait() to ensure the content of
  the pages have been moved to the new location before the new mapping
  is programmed into the NIC
* Add code to the ODP page fault handler to check the mapping status
* The new access flag added in v3 is removed.
* The checking for on-demand paging support in the new uverbs command
  is removed because it is implied by implementing the new ib_device
  method
* Clarify that dma-buf sg lists are page aligned

v3: https://www.spinics.net/lists/linux-rdma/msg96330.html
* Use dma_buf_dynamic_attach() instead of dma_buf_attach()
* Use on-demand paging mechanism to avoid pinning the GPU memory
* Instead of adding a new parameter to the device method for memory
  registration, pass all the attributes including the file descriptor
  as a structure
* Define a new access flag for dma-buf based memory region
* Check for on-demand paging support in the new uverbs command

v2: https://www.spinics.net/lists/linux-rdma/msg93643.html
* The Kconfig option is removed. There is no dependence issue since
  dma-buf driver is always enabled.
* The declaration of new data structure and functions is reorganized to
  minimize the visibility of the changes.
* The new uverbs command now goes through ioctl() instead of write().
* The rereg functionality is removed.
* Instead of adding new device method for dma-buf specific registration,
  existing method is extended to accept an extra parameter. 
* The correct function is now used for address range checking. 

v1: https://www.spinics.net/lists/linux-rdma/msg90720.html
* The initial patch set
* Implement core functions for importing and mapping dma-buf
* Use dma-buf static attach interface
* Add two ib_device methods reg_user_mr_fd() and rereg_user_mr_fd()
* Add two uverbs commands via the write() interface
* Add Kconfig option
* Add dma-buf support to mlx5 device

When enabled, an RDMA capable NIC can perform peer-to-peer transactions
over PCIe to access the local memory located on another device. This can
often lead to better performance than using a system memory buffer for
RDMA and copying data between the buffer and device memory.

Current kernel RDMA stack uses get_user_pages() to pin the physical
pages backing the user buffer and uses dma_map_sg_attrs() to get the
dma addresses for memory access. This usually doesn't work for peer
device memory due to the lack of associated page structures.

Several mechanisms exist today to facilitate device memory access.

ZONE_DEVICE is a new zone for device memory in the memory management
subsystem. It allows pages from device memory being described with
specialized page structures, but what can be done with these page
structures may be different from system memory. ZONE_DEVICE is further
specialized into multiple memory types, such as one type for PCI
p2pmem/p2pdma and one type for HMM.

PCI p2pmem/p2pdma uses ZONE_DEVICE to represent device memory residing
in a PCI BAR and provides a set of calls to publish, discover, allocate,
and map such memory for peer-to-peer transactions. One feature of the
API is that the buffer is allocated by the side that does the DMA
transfer. This works well with the storage usage case, but is awkward
with GPU-NIC communication, where typically the buffer is allocated by
the GPU driver rather than the NIC driver.

Heterogeneous Memory Management (HMM) utilizes mmu_interval_notifier
and ZONE_DEVICE to support shared virtual address space and page
migration between system memory and device memory. HMM doesn't support
pinning device memory because pages located on device must be able to
migrate to system memory when accessed by CPU. Peer-to-peer access
is currently not supported by HMM.

Dma-buf is a standard mechanism for sharing buffers among different
device drivers. The buffer to be shared is exported by the owning
driver and imported by the driver that wants to use it. The exporter
provides a set of ops that the importer can call to pin and map the
buffer. In addition, a file descriptor can be associated with a dma-
buf object as the handle that can be passed to user space.

This patch series adds dma-buf importer role to the RDMA driver in
attempt to support RDMA using device memory such as GPU VRAM. Dma-buf is
chosen for a few reasons: first, the API is relatively simple and allows
a lot of flexibility in implementing the buffer manipulation ops.
Second, it doesn't require page structure. Third, dma-buf is already
supported in many GPU drivers. However, we are aware that existing GPU
drivers don't allow pinning device memory via the dma-buf interface.
Pinning would simply cause the backing storage to migrate to system RAM.
True peer-to-peer access is only possible using dynamic attach, which
requires on-demand paging support from the NIC to work. For this reason,
this series only works with ODP capable NICs.

This series consists of four patches. The first patch adds the common
code for importing dma-buf from a file descriptor and mapping the
dma-buf pages. Patch 2 add the new driver method reg_user_mr_dmabuf().
Patch 3 adds a new uverbs command for registering dma-buf based memory
region. Patch 4 adds dma-buf support to the mlx5 driver.

Related user space RDMA library changes are provided as a separate
patch series.

Jianxin Xiong (4):
  RDMA/umem: Support importing dma-buf as user memory region
  RDMA/core: Add device method for registering dma-buf based memory
    region
  RDMA/uverbs: Add uverbs command for dma-buf based MR registration
  RDMA/mlx5: Support dma-buf based userspace memory region

 drivers/infiniband/core/Makefile              |   2 +-
 drivers/infiniband/core/device.c              |   1 +
 drivers/infiniband/core/umem.c                |   3 +
 drivers/infiniband/core/umem_dmabuf.c         | 173 ++++++++++++++++++++++++++
 drivers/infiniband/core/uverbs_std_types_mr.c | 117 ++++++++++++++++-
 drivers/infiniband/hw/mlx5/main.c             |   2 +
 drivers/infiniband/hw/mlx5/mlx5_ib.h          |  18 +++
 drivers/infiniband/hw/mlx5/mr.c               | 128 ++++++++++++++++++-
 drivers/infiniband/hw/mlx5/odp.c              |  86 ++++++++++++-
 include/rdma/ib_umem.h                        |  43 ++++++-
 include/rdma/ib_verbs.h                       |   6 +-
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 +++
 12 files changed, 579 insertions(+), 14 deletions(-)
 create mode 100644 drivers/infiniband/core/umem_dmabuf.c

-- 
1.8.3.1


^ permalink raw reply	[flat|nested] 26+ messages in thread
* [PATCH v13 0/4] RDMA: Add dma-buf support
@ 2020-12-07 22:15 ` Jianxin Xiong
  0 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Leon Romanovsky, Jason Gunthorpe, Doug Ledford, Daniel Vetter,
	Christian Koenig, Jianxin Xiong

This is the thirteenth version of the patch set. Changelog:

v13:
* Rebase to the latest linux-rdma 'for-next' branch (5.10.0-rc6+)
* Check for device on-demand paging capability at the entry point of
  the new verbs command to avoid calling device's reg_user_mr_dmabuf()
  method when CONFIG_INFINIBAND_ON_DEMAND_PAGING is diabled.

v12: https://www.spinics.net/lists/linux-rdma/msg97943.html
* Move the prototype of function ib_umem_dmabuf_release() to ib_umem.h
  and remove umem_dmabuf.h
* Break a line that is too long

v11: https://www.spinics.net/lists/linux-rdma/msg97860.html
* Rework the parameter checking code inside ib_umem_dmabuf_get() 
* Fix incorrect error handling in the new verbs command handler
* Put a duplicated code sequence for checking iova and setting page size
  into a function
* In the invalidation callback, check for if the buffer has been mapped
  and thus the presence of a valid driver mr is ensured
* The patch that checks for dma_virt_ops is dropped because it is no
  longer needed
* The patch that documents that dma-buf size is fixed has landed at:
  https://cgit.freedesktop.org/drm/drm-misc/commit/?id=476b485be03c
  and thus is no longer included here
* The matching user space patch set is sent separately

v10: https://www.spinics.net/lists/linux-rdma/msg97483.html
* Don't map the pages in ib_umem_dmabuf_get(); use the size information
  of the dma-buf object to validate the umem size instead
* Use PAGE_SIZE directly instead of use ib_umem_find_best_pgsz() when
  the MR is created since the pages have not been mapped yet and dma-buf
  requires PAGE_SIZE anyway
* Always call mlx5_umem_find_best_pgsz() after mapping the pages to
  verify that the page size requirement is satisfied
* Add a patch to document that dma-buf size is fixed

v9: https://www.spinics.net/lists/linux-rdma/msg97432.html
* Clean up the code for sg list in-place modification
* Prevent dma-buf pages from being mapped multiple times
* Map the pages in ib_umem_dmabuf_get() so that inproper values of
  address/length/iova can be caught early
* Check for unsupported flags in the new uverbs command
* Add missing uverbs_finalize_uobj_create()
* Sort uverbs objects by name
* Fix formating issue -- unnecessary alignment of '='
* Unmap pages in mlx5_ib_fence_dmabuf_mr()
* Remove address range checking from pagefault_dmabuf_mr()

v8: https://www.spinics.net/lists/linux-rdma/msg97370.html
* Modify the dma-buf sg list in place to get a proper umem sg list and
  restore it before calling dma_buf_unmap_attachment()
* Validate the umem sg list with ib_umem_find_best_pgsz()
* Remove the logic for slicing the sg list at runtime

v7: https://www.spinics.net/lists/linux-rdma/msg97297.html
* Rebase on top of latest mlx5 MR patch series
* Slice dma-buf sg list at runtime instead of creating a new list
* Preload the buffer page mapping when the MR is created
* Move the 'dma_virt_ops' check into dma_buf_dynamic_attach()

v6: https://www.spinics.net/lists/linux-rdma/msg96923.html
* Move the dma-buf invalidation callback from the core to the device
  driver
* Move mapping update from work queue to pagefault handler
* Add dma-buf based MRs to the xarray of mmkeys so that the pagefault
  handler can be reached
* Update the new driver method and uverbs command signature by changing
  the paramter 'addr' to 'offset'
* Modify the sg list returned from dma_buf_map_attachment() based on
  the parameters 'offset' and 'length'
* Don't import dma-buf if 'dma_virt_ops' is used by the dma device
* The patch that clarifies dma-buf sg lists alignment has landed at
  https://cgit.freedesktop.org/drm/drm-misc/commit/?id=ac80cd17a615
  and thus is no longer included with this set

v5: https://www.spinics.net/lists/linux-rdma/msg96786.html
* Fix a few warnings reported by kernel test robot:
    - no previous prototype for function 'ib_umem_dmabuf_release' 
    - no previous prototype for function 'ib_umem_dmabuf_map_pages'
    - comparison of distinct pointer types in 'check_add_overflow'
* Add comment for the wait between getting the dma-buf sg tagle and
  updating the NIC page table

v4: https://www.spinics.net/lists/linux-rdma/msg96767.html
* Add a new ib_device method reg_user_mr_dmabuf() instead of expanding
  the existing method reg_user_mr()
* Use a separate code flow for dma-buf instead of adding special cases
  to the ODP memory region code path
* In invalidation callback, new mapping is updated as whole using work
  queue instead of being updated in page granularity in the page fault
  handler
* Use dma_resv_get_excl() and dma_fence_wait() to ensure the content of
  the pages have been moved to the new location before the new mapping
  is programmed into the NIC
* Add code to the ODP page fault handler to check the mapping status
* The new access flag added in v3 is removed.
* The checking for on-demand paging support in the new uverbs command
  is removed because it is implied by implementing the new ib_device
  method
* Clarify that dma-buf sg lists are page aligned

v3: https://www.spinics.net/lists/linux-rdma/msg96330.html
* Use dma_buf_dynamic_attach() instead of dma_buf_attach()
* Use on-demand paging mechanism to avoid pinning the GPU memory
* Instead of adding a new parameter to the device method for memory
  registration, pass all the attributes including the file descriptor
  as a structure
* Define a new access flag for dma-buf based memory region
* Check for on-demand paging support in the new uverbs command

v2: https://www.spinics.net/lists/linux-rdma/msg93643.html
* The Kconfig option is removed. There is no dependence issue since
  dma-buf driver is always enabled.
* The declaration of new data structure and functions is reorganized to
  minimize the visibility of the changes.
* The new uverbs command now goes through ioctl() instead of write().
* The rereg functionality is removed.
* Instead of adding new device method for dma-buf specific registration,
  existing method is extended to accept an extra parameter. 
* The correct function is now used for address range checking. 

v1: https://www.spinics.net/lists/linux-rdma/msg90720.html
* The initial patch set
* Implement core functions for importing and mapping dma-buf
* Use dma-buf static attach interface
* Add two ib_device methods reg_user_mr_fd() and rereg_user_mr_fd()
* Add two uverbs commands via the write() interface
* Add Kconfig option
* Add dma-buf support to mlx5 device

When enabled, an RDMA capable NIC can perform peer-to-peer transactions
over PCIe to access the local memory located on another device. This can
often lead to better performance than using a system memory buffer for
RDMA and copying data between the buffer and device memory.

Current kernel RDMA stack uses get_user_pages() to pin the physical
pages backing the user buffer and uses dma_map_sg_attrs() to get the
dma addresses for memory access. This usually doesn't work for peer
device memory due to the lack of associated page structures.

Several mechanisms exist today to facilitate device memory access.

ZONE_DEVICE is a new zone for device memory in the memory management
subsystem. It allows pages from device memory being described with
specialized page structures, but what can be done with these page
structures may be different from system memory. ZONE_DEVICE is further
specialized into multiple memory types, such as one type for PCI
p2pmem/p2pdma and one type for HMM.

PCI p2pmem/p2pdma uses ZONE_DEVICE to represent device memory residing
in a PCI BAR and provides a set of calls to publish, discover, allocate,
and map such memory for peer-to-peer transactions. One feature of the
API is that the buffer is allocated by the side that does the DMA
transfer. This works well with the storage usage case, but is awkward
with GPU-NIC communication, where typically the buffer is allocated by
the GPU driver rather than the NIC driver.

Heterogeneous Memory Management (HMM) utilizes mmu_interval_notifier
and ZONE_DEVICE to support shared virtual address space and page
migration between system memory and device memory. HMM doesn't support
pinning device memory because pages located on device must be able to
migrate to system memory when accessed by CPU. Peer-to-peer access
is currently not supported by HMM.

Dma-buf is a standard mechanism for sharing buffers among different
device drivers. The buffer to be shared is exported by the owning
driver and imported by the driver that wants to use it. The exporter
provides a set of ops that the importer can call to pin and map the
buffer. In addition, a file descriptor can be associated with a dma-
buf object as the handle that can be passed to user space.

This patch series adds dma-buf importer role to the RDMA driver in
attempt to support RDMA using device memory such as GPU VRAM. Dma-buf is
chosen for a few reasons: first, the API is relatively simple and allows
a lot of flexibility in implementing the buffer manipulation ops.
Second, it doesn't require page structure. Third, dma-buf is already
supported in many GPU drivers. However, we are aware that existing GPU
drivers don't allow pinning device memory via the dma-buf interface.
Pinning would simply cause the backing storage to migrate to system RAM.
True peer-to-peer access is only possible using dynamic attach, which
requires on-demand paging support from the NIC to work. For this reason,
this series only works with ODP capable NICs.

This series consists of four patches. The first patch adds the common
code for importing dma-buf from a file descriptor and mapping the
dma-buf pages. Patch 2 add the new driver method reg_user_mr_dmabuf().
Patch 3 adds a new uverbs command for registering dma-buf based memory
region. Patch 4 adds dma-buf support to the mlx5 driver.

Related user space RDMA library changes are provided as a separate
patch series.

Jianxin Xiong (4):
  RDMA/umem: Support importing dma-buf as user memory region
  RDMA/core: Add device method for registering dma-buf based memory
    region
  RDMA/uverbs: Add uverbs command for dma-buf based MR registration
  RDMA/mlx5: Support dma-buf based userspace memory region

 drivers/infiniband/core/Makefile              |   2 +-
 drivers/infiniband/core/device.c              |   1 +
 drivers/infiniband/core/umem.c                |   3 +
 drivers/infiniband/core/umem_dmabuf.c         | 173 ++++++++++++++++++++++++++
 drivers/infiniband/core/uverbs_std_types_mr.c | 117 ++++++++++++++++-
 drivers/infiniband/hw/mlx5/main.c             |   2 +
 drivers/infiniband/hw/mlx5/mlx5_ib.h          |  18 +++
 drivers/infiniband/hw/mlx5/mr.c               | 128 ++++++++++++++++++-
 drivers/infiniband/hw/mlx5/odp.c              |  86 ++++++++++++-
 include/rdma/ib_umem.h                        |  43 ++++++-
 include/rdma/ib_verbs.h                       |   6 +-
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 +++
 12 files changed, 579 insertions(+), 14 deletions(-)
 create mode 100644 drivers/infiniband/core/umem_dmabuf.c

-- 
1.8.3.1

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-07 22:15 ` Jianxin Xiong
@ 2020-12-07 22:15   ` Jianxin Xiong
  -1 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Jianxin Xiong, Doug Ledford, Jason Gunthorpe, Leon Romanovsky,
	Sumit Semwal, Christian Koenig, Daniel Vetter

Dma-buf is a standard cross-driver buffer sharing mechanism that can be
used to support peer-to-peer access from RDMA devices.

Device memory exported via dma-buf is associated with a file descriptor.
This is passed to the user space as a property associated with the
buffer allocation. When the buffer is registered as a memory region,
the file descriptor is passed to the RDMA driver along with other
parameters.

Implement the common code for importing dma-buf object and mapping
dma-buf pages.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Conflicts:
	include/rdma/ib_umem.h
---
 drivers/infiniband/core/Makefile      |   2 +-
 drivers/infiniband/core/umem.c        |   3 +
 drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
 include/rdma/ib_umem.h                |  43 ++++++++-
 4 files changed, 219 insertions(+), 2 deletions(-)
 create mode 100644 drivers/infiniband/core/umem_dmabuf.c

diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
index ccf2670..8ab4eea 100644
--- a/drivers/infiniband/core/Makefile
+++ b/drivers/infiniband/core/Makefile
@@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
 				uverbs_std_types_srq.o \
 				uverbs_std_types_wq.o \
 				uverbs_std_types_qp.o
-ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
+ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
 ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 7ca4112..cc131f8 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -2,6 +2,7 @@
  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2020 Intel Corporation. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)
 {
 	if (!umem)
 		return;
+	if (umem->is_dmabuf)
+		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
 	if (umem->is_odp)
 		return ib_umem_odp_release(to_ib_umem_odp(umem));
 
diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
new file mode 100644
index 0000000..e50b955
--- /dev/null
+++ b/drivers/infiniband/core/umem_dmabuf.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * Copyright (c) 2020 Intel Corporation. All rights reserved.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
+#include <linux/dma-mapping.h>
+
+#include "uverbs.h"
+
+int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	struct sg_table *sgt;
+	struct scatterlist *sg;
+	struct dma_fence *fence;
+	unsigned long start, end, cur;
+	unsigned int nmap;
+	int i;
+
+	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
+
+	if (umem_dmabuf->sgt)
+		return 0;
+
+	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sgt))
+		return PTR_ERR(sgt);
+
+	/* modify the sg list in-place to match umem address and length */
+
+	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
+	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
+		    PAGE_SIZE);
+	cur = 0;
+	nmap = 0;
+	for_each_sgtable_dma_sg(sgt, sg, i) {
+		if (start < cur + sg_dma_len(sg) && cur < end)
+			nmap++;
+		if (cur <= start && start < cur + sg_dma_len(sg)) {
+			unsigned long offset = start - cur;
+
+			umem_dmabuf->first_sg = sg;
+			umem_dmabuf->first_sg_offset = offset;
+			sg_dma_address(sg) += offset;
+			sg_dma_len(sg) -= offset;
+			cur += offset;
+		}
+		if (cur < end && end <= cur + sg_dma_len(sg)) {
+			unsigned long trim = cur + sg_dma_len(sg) - end;
+
+			umem_dmabuf->last_sg = sg;
+			umem_dmabuf->last_sg_trim = trim;
+			sg_dma_len(sg) -= trim;
+			break;
+		}
+		cur += sg_dma_len(sg);
+	}
+
+	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
+	umem_dmabuf->umem.sg_head.nents = nmap;
+	umem_dmabuf->umem.nmap = nmap;
+	umem_dmabuf->sgt = sgt;
+
+	/*
+	 * Although the sg list is valid now, the content of the pages
+	 * may be not up-to-date. Wait for the exporter to finish
+	 * the migration.
+	 */
+	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
+	if (fence)
+		dma_fence_wait(fence, false);
+
+	return 0;
+}
+EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
+
+void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
+
+	if (!umem_dmabuf->sgt)
+		return;
+
+	/* retore the original sg list */
+	if (umem_dmabuf->first_sg) {
+		sg_dma_address(umem_dmabuf->first_sg) -=
+			umem_dmabuf->first_sg_offset;
+		sg_dma_len(umem_dmabuf->first_sg) +=
+			umem_dmabuf->first_sg_offset;
+		umem_dmabuf->first_sg = NULL;
+		umem_dmabuf->first_sg_offset = 0;
+	}
+	if (umem_dmabuf->last_sg) {
+		sg_dma_len(umem_dmabuf->last_sg) +=
+			umem_dmabuf->last_sg_trim;
+		umem_dmabuf->last_sg = NULL;
+		umem_dmabuf->last_sg_trim = 0;
+	}
+
+	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
+				 DMA_BIDIRECTIONAL);
+
+	umem_dmabuf->sgt = NULL;
+}
+EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
+
+struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
+				   unsigned long offset, size_t size,
+				   int fd, int access,
+				   const struct dma_buf_attach_ops *ops)
+{
+	struct dma_buf *dmabuf;
+	struct ib_umem_dmabuf *umem_dmabuf;
+	struct ib_umem *umem;
+	unsigned long end;
+	long ret = -EINVAL;
+
+	if (check_add_overflow(offset, (unsigned long)size, &end))
+		return ERR_PTR(-EINVAL);
+
+	if (unlikely(!ops || !ops->move_notify))
+		return ERR_PTR(-EINVAL);
+
+	dmabuf = dma_buf_get(fd);
+	if (IS_ERR(dmabuf))
+		return (void *)dmabuf;
+
+	if (dmabuf->size < end)
+		goto out_release_dmabuf;
+
+	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
+	if (!umem_dmabuf)
+		return ERR_PTR(-ENOMEM);
+
+	umem = &umem_dmabuf->umem;
+	umem->ibdev = device;
+	umem->length = size;
+	umem->address = offset;
+	umem->writable = ib_access_writable(access);
+	umem->is_dmabuf = 1;
+
+	if (unlikely(!ib_umem_num_pages(umem)))
+		goto out_free_umem;
+
+	umem_dmabuf->attach = dma_buf_dynamic_attach(
+					dmabuf,
+					device->dma_device,
+					ops,
+					umem_dmabuf);
+	if (IS_ERR(umem_dmabuf->attach)) {
+		ret = PTR_ERR(umem_dmabuf->attach);
+		goto out_free_umem;
+	}
+	return umem;
+
+out_free_umem:
+	kfree(umem_dmabuf);
+
+out_release_dmabuf:
+	dma_buf_put(dmabuf);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(ib_umem_dmabuf_get);
+
+void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
+
+	dma_buf_detach(dmabuf, umem_dmabuf->attach);
+	dma_buf_put(dmabuf);
+	kfree(umem_dmabuf);
+}
diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 7752211..b49a96d 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
 /*
  * Copyright (c) 2007 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2020 Intel Corporation.  All rights reserved.
  */
 
 #ifndef IB_UMEM_H
@@ -13,6 +14,7 @@
 
 struct ib_ucontext;
 struct ib_umem_odp;
+struct dma_buf_attach_ops;
 
 struct ib_umem {
 	struct ib_device       *ibdev;
@@ -22,12 +24,29 @@ struct ib_umem {
 	unsigned long		address;
 	u32 writable : 1;
 	u32 is_odp : 1;
+	u32 is_dmabuf : 1;
 	struct work_struct	work;
 	struct sg_table sg_head;
 	int             nmap;
 	unsigned int    sg_nents;
 };
 
+struct ib_umem_dmabuf {
+	struct ib_umem umem;
+	struct dma_buf_attachment *attach;
+	struct sg_table *sgt;
+	struct scatterlist *first_sg;
+	struct scatterlist *last_sg;
+	unsigned long first_sg_offset;
+	unsigned long last_sg_trim;
+	void *private;
+};
+
+static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
+{
+	return container_of(umem, struct ib_umem_dmabuf, umem);
+}
+
 /* Returns the offset of the umem start relative to the first page. */
 static inline int ib_umem_offset(struct ib_umem *umem)
 {
@@ -86,6 +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
 				     unsigned long pgsz_bitmap,
 				     unsigned long virt);
+
 /**
  * ib_umem_find_best_pgoff - Find best HW page size
  *
@@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 				      dma_addr & pgoff_bitmask);
 }
 
+struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
+				   unsigned long offset, size_t size,
+				   int fd, int access,
+				   const struct dma_buf_attach_ops *ops);
+int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
+void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
+void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
+
 #else /* CONFIG_INFINIBAND_USER_MEM */
 
 #include <linux/err.h>
@@ -143,7 +171,20 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 {
 	return 0;
 }
+static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
+						 unsigned long offset,
+						 size_t size, int fd,
+						 int access,
+						 struct dma_buf_attach_ops *ops)
+{
+	return ERR_PTR(-EINVAL);
+}
+static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	return -EINVAL;
+}
+static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
+static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
 
 #endif /* CONFIG_INFINIBAND_USER_MEM */
-
 #endif /* IB_UMEM_H */
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-07 22:15   ` Jianxin Xiong
  0 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Leon Romanovsky, Jason Gunthorpe, Doug Ledford, Daniel Vetter,
	Christian Koenig, Jianxin Xiong

Dma-buf is a standard cross-driver buffer sharing mechanism that can be
used to support peer-to-peer access from RDMA devices.

Device memory exported via dma-buf is associated with a file descriptor.
This is passed to the user space as a property associated with the
buffer allocation. When the buffer is registered as a memory region,
the file descriptor is passed to the RDMA driver along with other
parameters.

Implement the common code for importing dma-buf object and mapping
dma-buf pages.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Conflicts:
	include/rdma/ib_umem.h
---
 drivers/infiniband/core/Makefile      |   2 +-
 drivers/infiniband/core/umem.c        |   3 +
 drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
 include/rdma/ib_umem.h                |  43 ++++++++-
 4 files changed, 219 insertions(+), 2 deletions(-)
 create mode 100644 drivers/infiniband/core/umem_dmabuf.c

diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
index ccf2670..8ab4eea 100644
--- a/drivers/infiniband/core/Makefile
+++ b/drivers/infiniband/core/Makefile
@@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
 				uverbs_std_types_srq.o \
 				uverbs_std_types_wq.o \
 				uverbs_std_types_qp.o
-ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
+ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
 ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 7ca4112..cc131f8 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -2,6 +2,7 @@
  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2020 Intel Corporation. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)
 {
 	if (!umem)
 		return;
+	if (umem->is_dmabuf)
+		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
 	if (umem->is_odp)
 		return ib_umem_odp_release(to_ib_umem_odp(umem));
 
diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
new file mode 100644
index 0000000..e50b955
--- /dev/null
+++ b/drivers/infiniband/core/umem_dmabuf.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * Copyright (c) 2020 Intel Corporation. All rights reserved.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
+#include <linux/dma-mapping.h>
+
+#include "uverbs.h"
+
+int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	struct sg_table *sgt;
+	struct scatterlist *sg;
+	struct dma_fence *fence;
+	unsigned long start, end, cur;
+	unsigned int nmap;
+	int i;
+
+	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
+
+	if (umem_dmabuf->sgt)
+		return 0;
+
+	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sgt))
+		return PTR_ERR(sgt);
+
+	/* modify the sg list in-place to match umem address and length */
+
+	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
+	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
+		    PAGE_SIZE);
+	cur = 0;
+	nmap = 0;
+	for_each_sgtable_dma_sg(sgt, sg, i) {
+		if (start < cur + sg_dma_len(sg) && cur < end)
+			nmap++;
+		if (cur <= start && start < cur + sg_dma_len(sg)) {
+			unsigned long offset = start - cur;
+
+			umem_dmabuf->first_sg = sg;
+			umem_dmabuf->first_sg_offset = offset;
+			sg_dma_address(sg) += offset;
+			sg_dma_len(sg) -= offset;
+			cur += offset;
+		}
+		if (cur < end && end <= cur + sg_dma_len(sg)) {
+			unsigned long trim = cur + sg_dma_len(sg) - end;
+
+			umem_dmabuf->last_sg = sg;
+			umem_dmabuf->last_sg_trim = trim;
+			sg_dma_len(sg) -= trim;
+			break;
+		}
+		cur += sg_dma_len(sg);
+	}
+
+	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
+	umem_dmabuf->umem.sg_head.nents = nmap;
+	umem_dmabuf->umem.nmap = nmap;
+	umem_dmabuf->sgt = sgt;
+
+	/*
+	 * Although the sg list is valid now, the content of the pages
+	 * may be not up-to-date. Wait for the exporter to finish
+	 * the migration.
+	 */
+	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
+	if (fence)
+		dma_fence_wait(fence, false);
+
+	return 0;
+}
+EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
+
+void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
+
+	if (!umem_dmabuf->sgt)
+		return;
+
+	/* retore the original sg list */
+	if (umem_dmabuf->first_sg) {
+		sg_dma_address(umem_dmabuf->first_sg) -=
+			umem_dmabuf->first_sg_offset;
+		sg_dma_len(umem_dmabuf->first_sg) +=
+			umem_dmabuf->first_sg_offset;
+		umem_dmabuf->first_sg = NULL;
+		umem_dmabuf->first_sg_offset = 0;
+	}
+	if (umem_dmabuf->last_sg) {
+		sg_dma_len(umem_dmabuf->last_sg) +=
+			umem_dmabuf->last_sg_trim;
+		umem_dmabuf->last_sg = NULL;
+		umem_dmabuf->last_sg_trim = 0;
+	}
+
+	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
+				 DMA_BIDIRECTIONAL);
+
+	umem_dmabuf->sgt = NULL;
+}
+EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
+
+struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
+				   unsigned long offset, size_t size,
+				   int fd, int access,
+				   const struct dma_buf_attach_ops *ops)
+{
+	struct dma_buf *dmabuf;
+	struct ib_umem_dmabuf *umem_dmabuf;
+	struct ib_umem *umem;
+	unsigned long end;
+	long ret = -EINVAL;
+
+	if (check_add_overflow(offset, (unsigned long)size, &end))
+		return ERR_PTR(-EINVAL);
+
+	if (unlikely(!ops || !ops->move_notify))
+		return ERR_PTR(-EINVAL);
+
+	dmabuf = dma_buf_get(fd);
+	if (IS_ERR(dmabuf))
+		return (void *)dmabuf;
+
+	if (dmabuf->size < end)
+		goto out_release_dmabuf;
+
+	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
+	if (!umem_dmabuf)
+		return ERR_PTR(-ENOMEM);
+
+	umem = &umem_dmabuf->umem;
+	umem->ibdev = device;
+	umem->length = size;
+	umem->address = offset;
+	umem->writable = ib_access_writable(access);
+	umem->is_dmabuf = 1;
+
+	if (unlikely(!ib_umem_num_pages(umem)))
+		goto out_free_umem;
+
+	umem_dmabuf->attach = dma_buf_dynamic_attach(
+					dmabuf,
+					device->dma_device,
+					ops,
+					umem_dmabuf);
+	if (IS_ERR(umem_dmabuf->attach)) {
+		ret = PTR_ERR(umem_dmabuf->attach);
+		goto out_free_umem;
+	}
+	return umem;
+
+out_free_umem:
+	kfree(umem_dmabuf);
+
+out_release_dmabuf:
+	dma_buf_put(dmabuf);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(ib_umem_dmabuf_get);
+
+void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
+
+	dma_buf_detach(dmabuf, umem_dmabuf->attach);
+	dma_buf_put(dmabuf);
+	kfree(umem_dmabuf);
+}
diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 7752211..b49a96d 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
 /*
  * Copyright (c) 2007 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2020 Intel Corporation.  All rights reserved.
  */
 
 #ifndef IB_UMEM_H
@@ -13,6 +14,7 @@
 
 struct ib_ucontext;
 struct ib_umem_odp;
+struct dma_buf_attach_ops;
 
 struct ib_umem {
 	struct ib_device       *ibdev;
@@ -22,12 +24,29 @@ struct ib_umem {
 	unsigned long		address;
 	u32 writable : 1;
 	u32 is_odp : 1;
+	u32 is_dmabuf : 1;
 	struct work_struct	work;
 	struct sg_table sg_head;
 	int             nmap;
 	unsigned int    sg_nents;
 };
 
+struct ib_umem_dmabuf {
+	struct ib_umem umem;
+	struct dma_buf_attachment *attach;
+	struct sg_table *sgt;
+	struct scatterlist *first_sg;
+	struct scatterlist *last_sg;
+	unsigned long first_sg_offset;
+	unsigned long last_sg_trim;
+	void *private;
+};
+
+static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
+{
+	return container_of(umem, struct ib_umem_dmabuf, umem);
+}
+
 /* Returns the offset of the umem start relative to the first page. */
 static inline int ib_umem_offset(struct ib_umem *umem)
 {
@@ -86,6 +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
 				     unsigned long pgsz_bitmap,
 				     unsigned long virt);
+
 /**
  * ib_umem_find_best_pgoff - Find best HW page size
  *
@@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 				      dma_addr & pgoff_bitmask);
 }
 
+struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
+				   unsigned long offset, size_t size,
+				   int fd, int access,
+				   const struct dma_buf_attach_ops *ops);
+int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
+void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
+void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
+
 #else /* CONFIG_INFINIBAND_USER_MEM */
 
 #include <linux/err.h>
@@ -143,7 +171,20 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 {
 	return 0;
 }
+static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
+						 unsigned long offset,
+						 size_t size, int fd,
+						 int access,
+						 struct dma_buf_attach_ops *ops)
+{
+	return ERR_PTR(-EINVAL);
+}
+static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
+{
+	return -EINVAL;
+}
+static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
+static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
 
 #endif /* CONFIG_INFINIBAND_USER_MEM */
-
 #endif /* IB_UMEM_H */
-- 
1.8.3.1

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 2/4] RDMA/core: Add device method for registering dma-buf based memory region
  2020-12-07 22:15 ` Jianxin Xiong
@ 2020-12-07 22:15   ` Jianxin Xiong
  -1 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Jianxin Xiong, Doug Ledford, Jason Gunthorpe, Leon Romanovsky,
	Sumit Semwal, Christian Koenig, Daniel Vetter

Dma-buf based memory region requires one extra parameter and is processed
quite differently. Adding a separate method allows clean separation from
regular memory regions.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/infiniband/core/device.c | 1 +
 include/rdma/ib_verbs.h          | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 3ab1ede..23f7440 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2677,6 +2677,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
 	SET_DEVICE_OP(dev_ops, read_counters);
 	SET_DEVICE_OP(dev_ops, reg_dm_mr);
 	SET_DEVICE_OP(dev_ops, reg_user_mr);
+	SET_DEVICE_OP(dev_ops, reg_user_mr_dmabuf);
 	SET_DEVICE_OP(dev_ops, req_ncomp_notif);
 	SET_DEVICE_OP(dev_ops, req_notify_cq);
 	SET_DEVICE_OP(dev_ops, rereg_user_mr);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 7bee8ab..fa3882b 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2,7 +2,7 @@
 /*
  * Copyright (c) 2004 Mellanox Technologies Ltd.  All rights reserved.
  * Copyright (c) 2004 Infinicon Corporation.  All rights reserved.
- * Copyright (c) 2004 Intel Corporation.  All rights reserved.
+ * Copyright (c) 2004, 2020 Intel Corporation.  All rights reserved.
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004 Voltaire Corporation.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@@ -2433,6 +2433,10 @@ struct ib_device_ops {
 	struct ib_mr *(*reg_user_mr)(struct ib_pd *pd, u64 start, u64 length,
 				     u64 virt_addr, int mr_access_flags,
 				     struct ib_udata *udata);
+	struct ib_mr *(*reg_user_mr_dmabuf)(struct ib_pd *pd, u64 offset,
+				     u64 length, u64 virt_addr, int fd,
+				     int mr_access_flags,
+				     struct ib_udata *udata);
 	int (*rereg_user_mr)(struct ib_mr *mr, int flags, u64 start, u64 length,
 			     u64 virt_addr, int mr_access_flags,
 			     struct ib_pd *pd, struct ib_udata *udata);
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 2/4] RDMA/core: Add device method for registering dma-buf based memory region
@ 2020-12-07 22:15   ` Jianxin Xiong
  0 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Leon Romanovsky, Jason Gunthorpe, Doug Ledford, Daniel Vetter,
	Christian Koenig, Jianxin Xiong

Dma-buf based memory region requires one extra parameter and is processed
quite differently. Adding a separate method allows clean separation from
regular memory regions.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/infiniband/core/device.c | 1 +
 include/rdma/ib_verbs.h          | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 3ab1ede..23f7440 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2677,6 +2677,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
 	SET_DEVICE_OP(dev_ops, read_counters);
 	SET_DEVICE_OP(dev_ops, reg_dm_mr);
 	SET_DEVICE_OP(dev_ops, reg_user_mr);
+	SET_DEVICE_OP(dev_ops, reg_user_mr_dmabuf);
 	SET_DEVICE_OP(dev_ops, req_ncomp_notif);
 	SET_DEVICE_OP(dev_ops, req_notify_cq);
 	SET_DEVICE_OP(dev_ops, rereg_user_mr);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 7bee8ab..fa3882b 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2,7 +2,7 @@
 /*
  * Copyright (c) 2004 Mellanox Technologies Ltd.  All rights reserved.
  * Copyright (c) 2004 Infinicon Corporation.  All rights reserved.
- * Copyright (c) 2004 Intel Corporation.  All rights reserved.
+ * Copyright (c) 2004, 2020 Intel Corporation.  All rights reserved.
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004 Voltaire Corporation.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@@ -2433,6 +2433,10 @@ struct ib_device_ops {
 	struct ib_mr *(*reg_user_mr)(struct ib_pd *pd, u64 start, u64 length,
 				     u64 virt_addr, int mr_access_flags,
 				     struct ib_udata *udata);
+	struct ib_mr *(*reg_user_mr_dmabuf)(struct ib_pd *pd, u64 offset,
+				     u64 length, u64 virt_addr, int fd,
+				     int mr_access_flags,
+				     struct ib_udata *udata);
 	int (*rereg_user_mr)(struct ib_mr *mr, int flags, u64 start, u64 length,
 			     u64 virt_addr, int mr_access_flags,
 			     struct ib_pd *pd, struct ib_udata *udata);
-- 
1.8.3.1

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 3/4] RDMA/uverbs: Add uverbs command for dma-buf based MR registration
  2020-12-07 22:15 ` Jianxin Xiong
@ 2020-12-07 22:15   ` Jianxin Xiong
  -1 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Jianxin Xiong, Doug Ledford, Jason Gunthorpe, Leon Romanovsky,
	Sumit Semwal, Christian Koenig, Daniel Vetter

Implement a new uverbs ioctl method for memory registration with file
descriptor as an extra parameter.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/infiniband/core/uverbs_std_types_mr.c | 117 +++++++++++++++++++++++++-
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 +++
 2 files changed, 129 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_std_types_mr.c b/drivers/infiniband/core/uverbs_std_types_mr.c
index dc58564..4660c76 100644
--- a/drivers/infiniband/core/uverbs_std_types_mr.c
+++ b/drivers/infiniband/core/uverbs_std_types_mr.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ * Copyright (c) 2020, Intel Corporation.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -182,6 +183,86 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_MR)(
 	return IS_UVERBS_COPY_ERR(ret) ? ret : 0;
 }
 
+static int UVERBS_HANDLER(UVERBS_METHOD_REG_DMABUF_MR)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct ib_uobject *uobj =
+		uverbs_attr_get_uobject(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE);
+	struct ib_pd *pd =
+		uverbs_attr_get_obj(attrs, UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE);
+	struct ib_device *ib_dev = pd->device;
+
+	u64 offset, length, virt_addr;
+	u32 fd, access_flags;
+	struct ib_mr *mr;
+	int ret;
+
+	if (!ib_dev->ops.reg_user_mr_dmabuf)
+		return -EOPNOTSUPP;
+
+	if (!(pd->device->attrs.device_cap_flags & IB_DEVICE_ON_DEMAND_PAGING))
+		return -EOPNOTSUPP;
+
+	ret = uverbs_copy_from(&offset, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_OFFSET);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&length, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_LENGTH);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&virt_addr, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_IOVA);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&fd, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_FD);
+	if (ret)
+		return ret;
+
+	ret = uverbs_get_flags32(&access_flags, attrs,
+				 UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
+				 IB_ACCESS_LOCAL_WRITE |
+				 IB_ACCESS_REMOTE_READ |
+				 IB_ACCESS_REMOTE_WRITE |
+				 IB_ACCESS_REMOTE_ATOMIC |
+				 IB_ACCESS_RELAXED_ORDERING);
+	if (ret)
+		return ret;
+
+	ret = ib_check_mr_access(access_flags);
+	if (ret)
+		return ret;
+
+	mr = pd->device->ops.reg_user_mr_dmabuf(pd, offset, length, virt_addr,
+						fd, access_flags,
+						&attrs->driver_udata);
+	if (IS_ERR(mr))
+		return PTR_ERR(mr);
+
+	mr->device = pd->device;
+	mr->pd = pd;
+	mr->type = IB_MR_TYPE_USER;
+	mr->uobject = uobj;
+	atomic_inc(&pd->usecnt);
+
+	uobj->object = mr;
+
+	uverbs_finalize_uobj_create(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE);
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
+			     &mr->lkey, sizeof(mr->lkey));
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
+			     &mr->rkey, sizeof(mr->rkey));
+	return ret;
+}
+
 DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_METHOD_ADVISE_MR,
 	UVERBS_ATTR_IDR(UVERBS_ATTR_ADVISE_MR_PD_HANDLE,
@@ -247,6 +328,37 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_MR)(
 			    UVERBS_ATTR_TYPE(u32),
 			    UA_MANDATORY));
 
+DECLARE_UVERBS_NAMED_METHOD(
+	UVERBS_METHOD_REG_DMABUF_MR,
+	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DMABUF_MR_HANDLE,
+			UVERBS_OBJECT_MR,
+			UVERBS_ACCESS_NEW,
+			UA_MANDATORY),
+	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE,
+			UVERBS_OBJECT_PD,
+			UVERBS_ACCESS_READ,
+			UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_OFFSET,
+			   UVERBS_ATTR_TYPE(u64),
+			   UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_LENGTH,
+			   UVERBS_ATTR_TYPE(u64),
+			   UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_IOVA,
+			   UVERBS_ATTR_TYPE(u64),
+			   UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_FD,
+			   UVERBS_ATTR_TYPE(u32),
+			   UA_MANDATORY),
+	UVERBS_ATTR_FLAGS_IN(UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
+			     enum ib_access_flags),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
+			    UVERBS_ATTR_TYPE(u32),
+			    UA_MANDATORY),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
+			    UVERBS_ATTR_TYPE(u32),
+			    UA_MANDATORY));
+
 DECLARE_UVERBS_NAMED_METHOD_DESTROY(
 	UVERBS_METHOD_MR_DESTROY,
 	UVERBS_ATTR_IDR(UVERBS_ATTR_DESTROY_MR_HANDLE,
@@ -257,10 +369,11 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_MR)(
 DECLARE_UVERBS_NAMED_OBJECT(
 	UVERBS_OBJECT_MR,
 	UVERBS_TYPE_ALLOC_IDR(uverbs_free_mr),
+	&UVERBS_METHOD(UVERBS_METHOD_ADVISE_MR),
 	&UVERBS_METHOD(UVERBS_METHOD_DM_MR_REG),
 	&UVERBS_METHOD(UVERBS_METHOD_MR_DESTROY),
-	&UVERBS_METHOD(UVERBS_METHOD_ADVISE_MR),
-	&UVERBS_METHOD(UVERBS_METHOD_QUERY_MR));
+	&UVERBS_METHOD(UVERBS_METHOD_QUERY_MR),
+	&UVERBS_METHOD(UVERBS_METHOD_REG_DMABUF_MR));
 
 const struct uapi_definition uverbs_def_obj_mr[] = {
 	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(UVERBS_OBJECT_MR,
diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h
index 7968a18..dafc7eb 100644
--- a/include/uapi/rdma/ib_user_ioctl_cmds.h
+++ b/include/uapi/rdma/ib_user_ioctl_cmds.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -251,6 +252,7 @@ enum uverbs_methods_mr {
 	UVERBS_METHOD_MR_DESTROY,
 	UVERBS_METHOD_ADVISE_MR,
 	UVERBS_METHOD_QUERY_MR,
+	UVERBS_METHOD_REG_DMABUF_MR,
 };
 
 enum uverbs_attrs_mr_destroy_ids {
@@ -272,6 +274,18 @@ enum uverbs_attrs_query_mr_cmd_attr_ids {
 	UVERBS_ATTR_QUERY_MR_RESP_IOVA,
 };
 
+enum uverbs_attrs_reg_dmabuf_mr_cmd_attr_ids {
+	UVERBS_ATTR_REG_DMABUF_MR_HANDLE,
+	UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE,
+	UVERBS_ATTR_REG_DMABUF_MR_OFFSET,
+	UVERBS_ATTR_REG_DMABUF_MR_LENGTH,
+	UVERBS_ATTR_REG_DMABUF_MR_IOVA,
+	UVERBS_ATTR_REG_DMABUF_MR_FD,
+	UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
+	UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
+	UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
+};
+
 enum uverbs_attrs_create_counters_cmd_attr_ids {
 	UVERBS_ATTR_CREATE_COUNTERS_HANDLE,
 };
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 3/4] RDMA/uverbs: Add uverbs command for dma-buf based MR registration
@ 2020-12-07 22:15   ` Jianxin Xiong
  0 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Leon Romanovsky, Jason Gunthorpe, Doug Ledford, Daniel Vetter,
	Christian Koenig, Jianxin Xiong

Implement a new uverbs ioctl method for memory registration with file
descriptor as an extra parameter.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/infiniband/core/uverbs_std_types_mr.c | 117 +++++++++++++++++++++++++-
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 +++
 2 files changed, 129 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_std_types_mr.c b/drivers/infiniband/core/uverbs_std_types_mr.c
index dc58564..4660c76 100644
--- a/drivers/infiniband/core/uverbs_std_types_mr.c
+++ b/drivers/infiniband/core/uverbs_std_types_mr.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ * Copyright (c) 2020, Intel Corporation.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -182,6 +183,86 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_MR)(
 	return IS_UVERBS_COPY_ERR(ret) ? ret : 0;
 }
 
+static int UVERBS_HANDLER(UVERBS_METHOD_REG_DMABUF_MR)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct ib_uobject *uobj =
+		uverbs_attr_get_uobject(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE);
+	struct ib_pd *pd =
+		uverbs_attr_get_obj(attrs, UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE);
+	struct ib_device *ib_dev = pd->device;
+
+	u64 offset, length, virt_addr;
+	u32 fd, access_flags;
+	struct ib_mr *mr;
+	int ret;
+
+	if (!ib_dev->ops.reg_user_mr_dmabuf)
+		return -EOPNOTSUPP;
+
+	if (!(pd->device->attrs.device_cap_flags & IB_DEVICE_ON_DEMAND_PAGING))
+		return -EOPNOTSUPP;
+
+	ret = uverbs_copy_from(&offset, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_OFFSET);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&length, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_LENGTH);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&virt_addr, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_IOVA);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&fd, attrs,
+			       UVERBS_ATTR_REG_DMABUF_MR_FD);
+	if (ret)
+		return ret;
+
+	ret = uverbs_get_flags32(&access_flags, attrs,
+				 UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
+				 IB_ACCESS_LOCAL_WRITE |
+				 IB_ACCESS_REMOTE_READ |
+				 IB_ACCESS_REMOTE_WRITE |
+				 IB_ACCESS_REMOTE_ATOMIC |
+				 IB_ACCESS_RELAXED_ORDERING);
+	if (ret)
+		return ret;
+
+	ret = ib_check_mr_access(access_flags);
+	if (ret)
+		return ret;
+
+	mr = pd->device->ops.reg_user_mr_dmabuf(pd, offset, length, virt_addr,
+						fd, access_flags,
+						&attrs->driver_udata);
+	if (IS_ERR(mr))
+		return PTR_ERR(mr);
+
+	mr->device = pd->device;
+	mr->pd = pd;
+	mr->type = IB_MR_TYPE_USER;
+	mr->uobject = uobj;
+	atomic_inc(&pd->usecnt);
+
+	uobj->object = mr;
+
+	uverbs_finalize_uobj_create(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE);
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
+			     &mr->lkey, sizeof(mr->lkey));
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
+			     &mr->rkey, sizeof(mr->rkey));
+	return ret;
+}
+
 DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_METHOD_ADVISE_MR,
 	UVERBS_ATTR_IDR(UVERBS_ATTR_ADVISE_MR_PD_HANDLE,
@@ -247,6 +328,37 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_MR)(
 			    UVERBS_ATTR_TYPE(u32),
 			    UA_MANDATORY));
 
+DECLARE_UVERBS_NAMED_METHOD(
+	UVERBS_METHOD_REG_DMABUF_MR,
+	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DMABUF_MR_HANDLE,
+			UVERBS_OBJECT_MR,
+			UVERBS_ACCESS_NEW,
+			UA_MANDATORY),
+	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE,
+			UVERBS_OBJECT_PD,
+			UVERBS_ACCESS_READ,
+			UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_OFFSET,
+			   UVERBS_ATTR_TYPE(u64),
+			   UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_LENGTH,
+			   UVERBS_ATTR_TYPE(u64),
+			   UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_IOVA,
+			   UVERBS_ATTR_TYPE(u64),
+			   UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_FD,
+			   UVERBS_ATTR_TYPE(u32),
+			   UA_MANDATORY),
+	UVERBS_ATTR_FLAGS_IN(UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
+			     enum ib_access_flags),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
+			    UVERBS_ATTR_TYPE(u32),
+			    UA_MANDATORY),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
+			    UVERBS_ATTR_TYPE(u32),
+			    UA_MANDATORY));
+
 DECLARE_UVERBS_NAMED_METHOD_DESTROY(
 	UVERBS_METHOD_MR_DESTROY,
 	UVERBS_ATTR_IDR(UVERBS_ATTR_DESTROY_MR_HANDLE,
@@ -257,10 +369,11 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_MR)(
 DECLARE_UVERBS_NAMED_OBJECT(
 	UVERBS_OBJECT_MR,
 	UVERBS_TYPE_ALLOC_IDR(uverbs_free_mr),
+	&UVERBS_METHOD(UVERBS_METHOD_ADVISE_MR),
 	&UVERBS_METHOD(UVERBS_METHOD_DM_MR_REG),
 	&UVERBS_METHOD(UVERBS_METHOD_MR_DESTROY),
-	&UVERBS_METHOD(UVERBS_METHOD_ADVISE_MR),
-	&UVERBS_METHOD(UVERBS_METHOD_QUERY_MR));
+	&UVERBS_METHOD(UVERBS_METHOD_QUERY_MR),
+	&UVERBS_METHOD(UVERBS_METHOD_REG_DMABUF_MR));
 
 const struct uapi_definition uverbs_def_obj_mr[] = {
 	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(UVERBS_OBJECT_MR,
diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h
index 7968a18..dafc7eb 100644
--- a/include/uapi/rdma/ib_user_ioctl_cmds.h
+++ b/include/uapi/rdma/ib_user_ioctl_cmds.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -251,6 +252,7 @@ enum uverbs_methods_mr {
 	UVERBS_METHOD_MR_DESTROY,
 	UVERBS_METHOD_ADVISE_MR,
 	UVERBS_METHOD_QUERY_MR,
+	UVERBS_METHOD_REG_DMABUF_MR,
 };
 
 enum uverbs_attrs_mr_destroy_ids {
@@ -272,6 +274,18 @@ enum uverbs_attrs_query_mr_cmd_attr_ids {
 	UVERBS_ATTR_QUERY_MR_RESP_IOVA,
 };
 
+enum uverbs_attrs_reg_dmabuf_mr_cmd_attr_ids {
+	UVERBS_ATTR_REG_DMABUF_MR_HANDLE,
+	UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE,
+	UVERBS_ATTR_REG_DMABUF_MR_OFFSET,
+	UVERBS_ATTR_REG_DMABUF_MR_LENGTH,
+	UVERBS_ATTR_REG_DMABUF_MR_IOVA,
+	UVERBS_ATTR_REG_DMABUF_MR_FD,
+	UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
+	UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
+	UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
+};
+
 enum uverbs_attrs_create_counters_cmd_attr_ids {
 	UVERBS_ATTR_CREATE_COUNTERS_HANDLE,
 };
-- 
1.8.3.1

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 4/4] RDMA/mlx5: Support dma-buf based userspace memory region
  2020-12-07 22:15 ` Jianxin Xiong
@ 2020-12-07 22:15   ` Jianxin Xiong
  -1 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Jianxin Xiong, Doug Ledford, Jason Gunthorpe, Leon Romanovsky,
	Sumit Semwal, Christian Koenig, Daniel Vetter

Implement the new driver method 'reg_user_mr_dmabuf'.  Utilize the core
functions to import dma-buf based memory region and update the mappings.

Add code to handle dma-buf related page fault.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/infiniband/hw/mlx5/main.c    |   2 +
 drivers/infiniband/hw/mlx5/mlx5_ib.h |  18 +++++
 drivers/infiniband/hw/mlx5/mr.c      | 128 +++++++++++++++++++++++++++++++++--
 drivers/infiniband/hw/mlx5/odp.c     |  86 +++++++++++++++++++++--
 4 files changed, 225 insertions(+), 9 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 4a054eb..c025746 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
 /*
  * Copyright (c) 2013-2020, Mellanox Technologies inc. All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  */
 
 #include <linux/debugfs.h>
@@ -4069,6 +4070,7 @@ static int mlx5_ib_enable_driver(struct ib_device *dev)
 	.query_srq = mlx5_ib_query_srq,
 	.query_ucontext = mlx5_ib_query_ucontext,
 	.reg_user_mr = mlx5_ib_reg_user_mr,
+	.reg_user_mr_dmabuf = mlx5_ib_reg_user_mr_dmabuf,
 	.req_notify_cq = mlx5_ib_arm_cq,
 	.rereg_user_mr = mlx5_ib_rereg_user_mr,
 	.resize_cq = mlx5_ib_resize_cq,
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 718e59f..6f4d1b4 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
 /*
  * Copyright (c) 2013-2020, Mellanox Technologies inc. All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  */
 
 #ifndef MLX5_IB_H
@@ -704,6 +705,12 @@ static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
 	       mr->umem->is_odp;
 }
 
+static inline bool is_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem &&
+	       mr->umem->is_dmabuf;
+}
+
 struct mlx5_ib_mw {
 	struct ib_mw		ibmw;
 	struct mlx5_core_mkey	mmkey;
@@ -1239,6 +1246,10 @@ int mlx5_ib_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
 struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 				  u64 virt_addr, int access_flags,
 				  struct ib_udata *udata);
+struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 start,
+					 u64 length, u64 virt_addr,
+					 int fd, int access_flags,
+					 struct ib_udata *udata);
 int mlx5_ib_advise_mr(struct ib_pd *pd,
 		      enum ib_uverbs_advise_mr_advice advice,
 		      u32 flags,
@@ -1249,11 +1260,13 @@ int mlx5_ib_advise_mr(struct ib_pd *pd,
 int mlx5_ib_dealloc_mw(struct ib_mw *mw);
 int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
 		       int page_shift, int flags);
+int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags);
 struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
 					     struct ib_udata *udata,
 					     int access_flags);
 void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *mr);
 void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr);
+void mlx5_ib_fence_dmabuf_mr(struct mlx5_ib_mr *mr);
 int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 			  u64 length, u64 virt_addr, int access_flags,
 			  struct ib_pd *pd, struct ib_udata *udata);
@@ -1341,6 +1354,7 @@ int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
 			       enum ib_uverbs_advise_mr_advice advice,
 			       u32 flags, struct ib_sge *sg_list, u32 num_sge);
 int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable);
+int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr);
 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
 static inline void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
 {
@@ -1366,6 +1380,10 @@ static inline int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable)
 {
 	return -EOPNOTSUPP;
 }
+static inline int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
 
 extern const struct mmu_interval_notifier_ops mlx5_mn_ops;
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index b6116f6..e3be1f5 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -36,6 +37,8 @@
 #include <linux/debugfs.h>
 #include <linux/export.h>
 #include <linux/delay.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
 #include <rdma/ib_umem.h>
 #include <rdma/ib_umem_odp.h>
 #include <rdma/ib_verbs.h>
@@ -957,6 +960,16 @@ static struct mlx5_cache_ent *mr_cache_ent_from_order(struct mlx5_ib_dev *dev,
 	return &cache->ent[order];
 }
 
+static unsigned int mlx5_umem_dmabuf_default_pgsz(struct ib_umem *umem,
+						  u64 iova)
+{
+	if ((iova ^ umem->address) & (PAGE_SIZE - 1))
+		return 0;
+
+	umem->iova = iova;
+	return PAGE_SIZE;
+}
+
 static struct mlx5_ib_mr *alloc_mr_from_cache(struct ib_pd *pd,
 					      struct ib_umem *umem, u64 iova,
 					      int access_flags)
@@ -966,7 +979,11 @@ static struct mlx5_ib_mr *alloc_mr_from_cache(struct ib_pd *pd,
 	struct mlx5_ib_mr *mr;
 	unsigned int page_size;
 
-	page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, 0, iova);
+	if (umem->is_dmabuf)
+		page_size = mlx5_umem_dmabuf_default_pgsz(umem, iova);
+	else
+		page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size,
+						     0, iova);
 	if (WARN_ON(!page_size))
 		return ERR_PTR(-EINVAL);
 	ent = mr_cache_ent_from_order(
@@ -1212,8 +1229,10 @@ int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
 
 /*
  * Send the DMA list to the HW for a normal MR using UMR.
+ * Dmabuf MR is handled in a similar way, except that the MLX5_IB_UPD_XLT_ZAP
+ * flag may be used.
  */
-static int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags)
+int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags)
 {
 	struct mlx5_ib_dev *dev = mr->dev;
 	struct device *ddev = &dev->mdev->pdev->dev;
@@ -1255,6 +1274,10 @@ static int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags)
 		cur_mtt->ptag =
 			cpu_to_be64(rdma_block_iter_dma_address(&biter) |
 				    MLX5_IB_MTT_PRESENT);
+
+		if (mr->umem->is_dmabuf && (flags & MLX5_IB_UPD_XLT_ZAP))
+			cur_mtt->ptag = 0;
+
 		cur_mtt++;
 	}
 
@@ -1291,8 +1314,11 @@ static struct mlx5_ib_mr *reg_create(struct ib_mr *ibmr, struct ib_pd *pd,
 	int err;
 	bool pg_cap = !!(MLX5_CAP_GEN(dev->mdev, pg));
 
-	page_size =
-		mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, 0, iova);
+	if (umem->is_dmabuf)
+		page_size = mlx5_umem_dmabuf_default_pgsz(umem, iova);
+	else
+		page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size,
+						     0, iova);
 	if (WARN_ON(!page_size))
 		return ERR_PTR(-EINVAL);
 
@@ -1572,6 +1598,96 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 	return ERR_PTR(err);
 }
 
+static void mlx5_ib_dmabuf_invalidate_cb(struct dma_buf_attachment *attach)
+{
+	struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv;
+	struct mlx5_ib_mr *mr = umem_dmabuf->private;
+
+	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
+
+	if (!umem_dmabuf->sgt)
+		return;
+
+	mlx5_ib_update_mr_pas(mr, MLX5_IB_UPD_XLT_ZAP);
+	ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+}
+
+static struct dma_buf_attach_ops mlx5_ib_dmabuf_attach_ops = {
+	.allow_peer2peer = 1,
+	.move_notify = mlx5_ib_dmabuf_invalidate_cb,
+};
+
+struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 offset,
+					 u64 length, u64 virt_addr,
+					 int fd, int access_flags,
+					 struct ib_udata *udata)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
+	struct mlx5_ib_mr *mr = NULL;
+	struct ib_umem *umem;
+	int err;
+
+	if (!IS_ENABLED(CONFIG_INFINIBAND_USER_MEM))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	mlx5_ib_dbg(dev,
+		    "offset 0x%llx, virt_addr 0x%llx, length 0x%llx, fd %d, access_flags 0x%x\n",
+		    offset, virt_addr, length, fd, access_flags);
+
+	if (!mlx5_ib_can_load_pas_with_umr(dev, length))
+		return ERR_PTR(-EINVAL);
+
+	umem = ib_umem_dmabuf_get(&dev->ib_dev, offset, length, fd, access_flags,
+				  &mlx5_ib_dmabuf_attach_ops);
+	if (IS_ERR(umem)) {
+		mlx5_ib_dbg(dev, "umem get failed (%ld)\n", PTR_ERR(umem));
+		return ERR_PTR(PTR_ERR(umem));
+	}
+
+	mr = alloc_mr_from_cache(pd, umem, virt_addr, access_flags);
+	if (IS_ERR(mr))
+		mr = NULL;
+
+	if (!mr) {
+		mutex_lock(&dev->slow_path_mutex);
+		mr = reg_create(NULL, pd, umem, virt_addr, access_flags,
+				false);
+		mutex_unlock(&dev->slow_path_mutex);
+	}
+
+	if (IS_ERR(mr)) {
+		err = PTR_ERR(mr);
+		goto error;
+	}
+
+	mlx5_ib_dbg(dev, "mkey 0x%x\n", mr->mmkey.key);
+
+	mr->umem = umem;
+	atomic_add(ib_umem_num_pages(mr->umem), &dev->mdev->priv.reg_pages);
+	set_mr_fields(dev, mr, length, access_flags);
+
+	to_ib_umem_dmabuf(umem)->private = mr;
+	init_waitqueue_head(&mr->q_deferred_work);
+	atomic_set(&mr->num_deferred_work, 0);
+	err = xa_err(xa_store(&dev->odp_mkeys,
+			      mlx5_base_mkey(mr->mmkey.key), &mr->mmkey,
+			      GFP_KERNEL));
+	if (err) {
+		dereg_mr(dev, mr);
+		return ERR_PTR(err);
+	}
+
+	err = mlx5_ib_init_dmabuf_mr(mr);
+	if (err) {
+		dereg_mr(dev, mr);
+		return ERR_PTR(err);
+	}
+	return &mr->ibmr;
+error:
+	ib_umem_release(umem);
+	return ERR_PTR(err);
+}
+
 /**
  * mlx5_mr_cache_invalidate - Fence all DMA on the MR
  * @mr: The MR to fence
@@ -1640,7 +1756,7 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 	if (!mr->umem)
 		return -EINVAL;
 
-	if (is_odp_mr(mr))
+	if (is_odp_mr(mr) || is_dmabuf_mr(mr))
 		return -EOPNOTSUPP;
 
 	if (flags & IB_MR_REREG_TRANS) {
@@ -1804,6 +1920,8 @@ static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 	/* Stop all DMA */
 	if (is_odp_mr(mr))
 		mlx5_ib_fence_odp_mr(mr);
+	else if (is_dmabuf_mr(mr))
+		mlx5_ib_fence_dmabuf_mr(mr);
 	else
 		clean_mr(dev, mr);
 
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index 5c853ec..35d6770 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -33,6 +33,8 @@
 #include <rdma/ib_umem.h>
 #include <rdma/ib_umem_odp.h>
 #include <linux/kernel.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
 
 #include "mlx5_ib.h"
 #include "cmd.h"
@@ -664,6 +666,37 @@ void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr)
 	dma_fence_odp_mr(mr);
 }
 
+/**
+ * mlx5_ib_fence_dmabuf_mr - Stop all access to the dmabuf MR
+ * @mr: to fence
+ *
+ * On return no parallel threads will be touching this MR and no DMA will be
+ * active.
+ */
+void mlx5_ib_fence_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem);
+
+	/* Prevent new page faults and prefetch requests from succeeding */
+	xa_erase(&mr->dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key));
+
+	/* Wait for all running page-fault handlers to finish. */
+	synchronize_srcu(&mr->dev->odp_srcu);
+
+	wait_event(mr->q_deferred_work, !atomic_read(&mr->num_deferred_work));
+
+	dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+	mlx5_mr_cache_invalidate(mr);
+	umem_dmabuf->private = NULL;
+	ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+
+	if (!mr->cache_ent) {
+		mlx5_core_destroy_mkey(mr->dev->mdev, &mr->mmkey);
+		WARN_ON(mr->descs);
+	}
+}
+
 #define MLX5_PF_FLAGS_DOWNGRADE BIT(1)
 #define MLX5_PF_FLAGS_SNAPSHOT BIT(2)
 #define MLX5_PF_FLAGS_ENABLE BIT(3)
@@ -797,6 +830,41 @@ static int pagefault_implicit_mr(struct mlx5_ib_mr *imr,
 	return ret;
 }
 
+static int pagefault_dmabuf_mr(struct mlx5_ib_mr *mr, size_t bcnt,
+			       u32 *bytes_mapped, u32 flags)
+{
+	struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem);
+	u32 xlt_flags = 0;
+	int err;
+	unsigned int page_size;
+
+	if (flags & MLX5_PF_FLAGS_ENABLE)
+		xlt_flags |= MLX5_IB_UPD_XLT_ENABLE;
+
+	dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+	err = ib_umem_dmabuf_map_pages(umem_dmabuf);
+	if (!err) {
+		page_size = mlx5_umem_find_best_pgsz(&umem_dmabuf->umem, mkc,
+						     log_page_size, 0,
+						     umem_dmabuf->umem.iova);
+		if (unlikely(page_size < PAGE_SIZE)) {
+			ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+			err = -EINVAL;
+		} else {
+			err = mlx5_ib_update_mr_pas(mr, xlt_flags);
+		}
+	}
+	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+
+	if (err)
+		return err;
+
+	if (bytes_mapped)
+		*bytes_mapped += bcnt;
+
+	return ib_umem_num_pages(mr->umem);
+}
+
 /*
  * Returns:
  *  -EFAULT: The io_virt->bcnt is not within the MR, it covers pages that are
@@ -815,6 +883,9 @@ static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt,
 	if (unlikely(io_virt < mr->mmkey.iova))
 		return -EFAULT;
 
+	if (mr->umem->is_dmabuf)
+		return pagefault_dmabuf_mr(mr, bcnt, bytes_mapped, flags);
+
 	if (!odp->is_implicit_odp) {
 		u64 user_va;
 
@@ -845,6 +916,16 @@ int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable)
 	return ret >= 0 ? 0 : ret;
 }
 
+int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	int ret;
+
+	ret = pagefault_dmabuf_mr(mr, mr->umem->length, NULL,
+				  MLX5_PF_FLAGS_ENABLE);
+
+	return ret >= 0 ? 0 : ret;
+}
+
 struct pf_frame {
 	struct pf_frame *next;
 	u32 key;
@@ -1747,7 +1828,6 @@ static void destroy_prefetch_work(struct prefetch_mr_work *work)
 {
 	struct mlx5_ib_dev *dev = to_mdev(pd->device);
 	struct mlx5_core_mkey *mmkey;
-	struct ib_umem_odp *odp;
 	struct mlx5_ib_mr *mr;
 
 	lockdep_assert_held(&dev->odp_srcu);
@@ -1761,11 +1841,9 @@ static void destroy_prefetch_work(struct prefetch_mr_work *work)
 	if (mr->ibmr.pd != pd)
 		return NULL;
 
-	odp = to_ib_umem_odp(mr->umem);
-
 	/* prefetch with write-access must be supported by the MR */
 	if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE &&
-	    !odp->umem.writable)
+	    !mr->umem->writable)
 		return NULL;
 
 	return mr;
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v13 4/4] RDMA/mlx5: Support dma-buf based userspace memory region
@ 2020-12-07 22:15   ` Jianxin Xiong
  0 siblings, 0 replies; 26+ messages in thread
From: Jianxin Xiong @ 2020-12-07 22:15 UTC (permalink / raw)
  To: linux-rdma, dri-devel
  Cc: Leon Romanovsky, Jason Gunthorpe, Doug Ledford, Daniel Vetter,
	Christian Koenig, Jianxin Xiong

Implement the new driver method 'reg_user_mr_dmabuf'.  Utilize the core
functions to import dma-buf based memory region and update the mappings.

Add code to handle dma-buf related page fault.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/infiniband/hw/mlx5/main.c    |   2 +
 drivers/infiniband/hw/mlx5/mlx5_ib.h |  18 +++++
 drivers/infiniband/hw/mlx5/mr.c      | 128 +++++++++++++++++++++++++++++++++--
 drivers/infiniband/hw/mlx5/odp.c     |  86 +++++++++++++++++++++--
 4 files changed, 225 insertions(+), 9 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 4a054eb..c025746 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
 /*
  * Copyright (c) 2013-2020, Mellanox Technologies inc. All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  */
 
 #include <linux/debugfs.h>
@@ -4069,6 +4070,7 @@ static int mlx5_ib_enable_driver(struct ib_device *dev)
 	.query_srq = mlx5_ib_query_srq,
 	.query_ucontext = mlx5_ib_query_ucontext,
 	.reg_user_mr = mlx5_ib_reg_user_mr,
+	.reg_user_mr_dmabuf = mlx5_ib_reg_user_mr_dmabuf,
 	.req_notify_cq = mlx5_ib_arm_cq,
 	.rereg_user_mr = mlx5_ib_rereg_user_mr,
 	.resize_cq = mlx5_ib_resize_cq,
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 718e59f..6f4d1b4 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
 /*
  * Copyright (c) 2013-2020, Mellanox Technologies inc. All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  */
 
 #ifndef MLX5_IB_H
@@ -704,6 +705,12 @@ static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
 	       mr->umem->is_odp;
 }
 
+static inline bool is_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem &&
+	       mr->umem->is_dmabuf;
+}
+
 struct mlx5_ib_mw {
 	struct ib_mw		ibmw;
 	struct mlx5_core_mkey	mmkey;
@@ -1239,6 +1246,10 @@ int mlx5_ib_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
 struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 				  u64 virt_addr, int access_flags,
 				  struct ib_udata *udata);
+struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 start,
+					 u64 length, u64 virt_addr,
+					 int fd, int access_flags,
+					 struct ib_udata *udata);
 int mlx5_ib_advise_mr(struct ib_pd *pd,
 		      enum ib_uverbs_advise_mr_advice advice,
 		      u32 flags,
@@ -1249,11 +1260,13 @@ int mlx5_ib_advise_mr(struct ib_pd *pd,
 int mlx5_ib_dealloc_mw(struct ib_mw *mw);
 int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
 		       int page_shift, int flags);
+int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags);
 struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
 					     struct ib_udata *udata,
 					     int access_flags);
 void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *mr);
 void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr);
+void mlx5_ib_fence_dmabuf_mr(struct mlx5_ib_mr *mr);
 int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 			  u64 length, u64 virt_addr, int access_flags,
 			  struct ib_pd *pd, struct ib_udata *udata);
@@ -1341,6 +1354,7 @@ int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
 			       enum ib_uverbs_advise_mr_advice advice,
 			       u32 flags, struct ib_sge *sg_list, u32 num_sge);
 int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable);
+int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr);
 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
 static inline void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
 {
@@ -1366,6 +1380,10 @@ static inline int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable)
 {
 	return -EOPNOTSUPP;
 }
+static inline int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
 
 extern const struct mmu_interval_notifier_ops mlx5_mn_ops;
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index b6116f6..e3be1f5 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2020, Intel Corporation. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -36,6 +37,8 @@
 #include <linux/debugfs.h>
 #include <linux/export.h>
 #include <linux/delay.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
 #include <rdma/ib_umem.h>
 #include <rdma/ib_umem_odp.h>
 #include <rdma/ib_verbs.h>
@@ -957,6 +960,16 @@ static struct mlx5_cache_ent *mr_cache_ent_from_order(struct mlx5_ib_dev *dev,
 	return &cache->ent[order];
 }
 
+static unsigned int mlx5_umem_dmabuf_default_pgsz(struct ib_umem *umem,
+						  u64 iova)
+{
+	if ((iova ^ umem->address) & (PAGE_SIZE - 1))
+		return 0;
+
+	umem->iova = iova;
+	return PAGE_SIZE;
+}
+
 static struct mlx5_ib_mr *alloc_mr_from_cache(struct ib_pd *pd,
 					      struct ib_umem *umem, u64 iova,
 					      int access_flags)
@@ -966,7 +979,11 @@ static struct mlx5_ib_mr *alloc_mr_from_cache(struct ib_pd *pd,
 	struct mlx5_ib_mr *mr;
 	unsigned int page_size;
 
-	page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, 0, iova);
+	if (umem->is_dmabuf)
+		page_size = mlx5_umem_dmabuf_default_pgsz(umem, iova);
+	else
+		page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size,
+						     0, iova);
 	if (WARN_ON(!page_size))
 		return ERR_PTR(-EINVAL);
 	ent = mr_cache_ent_from_order(
@@ -1212,8 +1229,10 @@ int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
 
 /*
  * Send the DMA list to the HW for a normal MR using UMR.
+ * Dmabuf MR is handled in a similar way, except that the MLX5_IB_UPD_XLT_ZAP
+ * flag may be used.
  */
-static int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags)
+int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags)
 {
 	struct mlx5_ib_dev *dev = mr->dev;
 	struct device *ddev = &dev->mdev->pdev->dev;
@@ -1255,6 +1274,10 @@ static int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags)
 		cur_mtt->ptag =
 			cpu_to_be64(rdma_block_iter_dma_address(&biter) |
 				    MLX5_IB_MTT_PRESENT);
+
+		if (mr->umem->is_dmabuf && (flags & MLX5_IB_UPD_XLT_ZAP))
+			cur_mtt->ptag = 0;
+
 		cur_mtt++;
 	}
 
@@ -1291,8 +1314,11 @@ static struct mlx5_ib_mr *reg_create(struct ib_mr *ibmr, struct ib_pd *pd,
 	int err;
 	bool pg_cap = !!(MLX5_CAP_GEN(dev->mdev, pg));
 
-	page_size =
-		mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, 0, iova);
+	if (umem->is_dmabuf)
+		page_size = mlx5_umem_dmabuf_default_pgsz(umem, iova);
+	else
+		page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size,
+						     0, iova);
 	if (WARN_ON(!page_size))
 		return ERR_PTR(-EINVAL);
 
@@ -1572,6 +1598,96 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 	return ERR_PTR(err);
 }
 
+static void mlx5_ib_dmabuf_invalidate_cb(struct dma_buf_attachment *attach)
+{
+	struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv;
+	struct mlx5_ib_mr *mr = umem_dmabuf->private;
+
+	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
+
+	if (!umem_dmabuf->sgt)
+		return;
+
+	mlx5_ib_update_mr_pas(mr, MLX5_IB_UPD_XLT_ZAP);
+	ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+}
+
+static struct dma_buf_attach_ops mlx5_ib_dmabuf_attach_ops = {
+	.allow_peer2peer = 1,
+	.move_notify = mlx5_ib_dmabuf_invalidate_cb,
+};
+
+struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 offset,
+					 u64 length, u64 virt_addr,
+					 int fd, int access_flags,
+					 struct ib_udata *udata)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
+	struct mlx5_ib_mr *mr = NULL;
+	struct ib_umem *umem;
+	int err;
+
+	if (!IS_ENABLED(CONFIG_INFINIBAND_USER_MEM))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	mlx5_ib_dbg(dev,
+		    "offset 0x%llx, virt_addr 0x%llx, length 0x%llx, fd %d, access_flags 0x%x\n",
+		    offset, virt_addr, length, fd, access_flags);
+
+	if (!mlx5_ib_can_load_pas_with_umr(dev, length))
+		return ERR_PTR(-EINVAL);
+
+	umem = ib_umem_dmabuf_get(&dev->ib_dev, offset, length, fd, access_flags,
+				  &mlx5_ib_dmabuf_attach_ops);
+	if (IS_ERR(umem)) {
+		mlx5_ib_dbg(dev, "umem get failed (%ld)\n", PTR_ERR(umem));
+		return ERR_PTR(PTR_ERR(umem));
+	}
+
+	mr = alloc_mr_from_cache(pd, umem, virt_addr, access_flags);
+	if (IS_ERR(mr))
+		mr = NULL;
+
+	if (!mr) {
+		mutex_lock(&dev->slow_path_mutex);
+		mr = reg_create(NULL, pd, umem, virt_addr, access_flags,
+				false);
+		mutex_unlock(&dev->slow_path_mutex);
+	}
+
+	if (IS_ERR(mr)) {
+		err = PTR_ERR(mr);
+		goto error;
+	}
+
+	mlx5_ib_dbg(dev, "mkey 0x%x\n", mr->mmkey.key);
+
+	mr->umem = umem;
+	atomic_add(ib_umem_num_pages(mr->umem), &dev->mdev->priv.reg_pages);
+	set_mr_fields(dev, mr, length, access_flags);
+
+	to_ib_umem_dmabuf(umem)->private = mr;
+	init_waitqueue_head(&mr->q_deferred_work);
+	atomic_set(&mr->num_deferred_work, 0);
+	err = xa_err(xa_store(&dev->odp_mkeys,
+			      mlx5_base_mkey(mr->mmkey.key), &mr->mmkey,
+			      GFP_KERNEL));
+	if (err) {
+		dereg_mr(dev, mr);
+		return ERR_PTR(err);
+	}
+
+	err = mlx5_ib_init_dmabuf_mr(mr);
+	if (err) {
+		dereg_mr(dev, mr);
+		return ERR_PTR(err);
+	}
+	return &mr->ibmr;
+error:
+	ib_umem_release(umem);
+	return ERR_PTR(err);
+}
+
 /**
  * mlx5_mr_cache_invalidate - Fence all DMA on the MR
  * @mr: The MR to fence
@@ -1640,7 +1756,7 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 	if (!mr->umem)
 		return -EINVAL;
 
-	if (is_odp_mr(mr))
+	if (is_odp_mr(mr) || is_dmabuf_mr(mr))
 		return -EOPNOTSUPP;
 
 	if (flags & IB_MR_REREG_TRANS) {
@@ -1804,6 +1920,8 @@ static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 	/* Stop all DMA */
 	if (is_odp_mr(mr))
 		mlx5_ib_fence_odp_mr(mr);
+	else if (is_dmabuf_mr(mr))
+		mlx5_ib_fence_dmabuf_mr(mr);
 	else
 		clean_mr(dev, mr);
 
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index 5c853ec..35d6770 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -33,6 +33,8 @@
 #include <rdma/ib_umem.h>
 #include <rdma/ib_umem_odp.h>
 #include <linux/kernel.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
 
 #include "mlx5_ib.h"
 #include "cmd.h"
@@ -664,6 +666,37 @@ void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr)
 	dma_fence_odp_mr(mr);
 }
 
+/**
+ * mlx5_ib_fence_dmabuf_mr - Stop all access to the dmabuf MR
+ * @mr: to fence
+ *
+ * On return no parallel threads will be touching this MR and no DMA will be
+ * active.
+ */
+void mlx5_ib_fence_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem);
+
+	/* Prevent new page faults and prefetch requests from succeeding */
+	xa_erase(&mr->dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key));
+
+	/* Wait for all running page-fault handlers to finish. */
+	synchronize_srcu(&mr->dev->odp_srcu);
+
+	wait_event(mr->q_deferred_work, !atomic_read(&mr->num_deferred_work));
+
+	dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+	mlx5_mr_cache_invalidate(mr);
+	umem_dmabuf->private = NULL;
+	ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+
+	if (!mr->cache_ent) {
+		mlx5_core_destroy_mkey(mr->dev->mdev, &mr->mmkey);
+		WARN_ON(mr->descs);
+	}
+}
+
 #define MLX5_PF_FLAGS_DOWNGRADE BIT(1)
 #define MLX5_PF_FLAGS_SNAPSHOT BIT(2)
 #define MLX5_PF_FLAGS_ENABLE BIT(3)
@@ -797,6 +830,41 @@ static int pagefault_implicit_mr(struct mlx5_ib_mr *imr,
 	return ret;
 }
 
+static int pagefault_dmabuf_mr(struct mlx5_ib_mr *mr, size_t bcnt,
+			       u32 *bytes_mapped, u32 flags)
+{
+	struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem);
+	u32 xlt_flags = 0;
+	int err;
+	unsigned int page_size;
+
+	if (flags & MLX5_PF_FLAGS_ENABLE)
+		xlt_flags |= MLX5_IB_UPD_XLT_ENABLE;
+
+	dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+	err = ib_umem_dmabuf_map_pages(umem_dmabuf);
+	if (!err) {
+		page_size = mlx5_umem_find_best_pgsz(&umem_dmabuf->umem, mkc,
+						     log_page_size, 0,
+						     umem_dmabuf->umem.iova);
+		if (unlikely(page_size < PAGE_SIZE)) {
+			ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+			err = -EINVAL;
+		} else {
+			err = mlx5_ib_update_mr_pas(mr, xlt_flags);
+		}
+	}
+	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+
+	if (err)
+		return err;
+
+	if (bytes_mapped)
+		*bytes_mapped += bcnt;
+
+	return ib_umem_num_pages(mr->umem);
+}
+
 /*
  * Returns:
  *  -EFAULT: The io_virt->bcnt is not within the MR, it covers pages that are
@@ -815,6 +883,9 @@ static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt,
 	if (unlikely(io_virt < mr->mmkey.iova))
 		return -EFAULT;
 
+	if (mr->umem->is_dmabuf)
+		return pagefault_dmabuf_mr(mr, bcnt, bytes_mapped, flags);
+
 	if (!odp->is_implicit_odp) {
 		u64 user_va;
 
@@ -845,6 +916,16 @@ int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable)
 	return ret >= 0 ? 0 : ret;
 }
 
+int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr)
+{
+	int ret;
+
+	ret = pagefault_dmabuf_mr(mr, mr->umem->length, NULL,
+				  MLX5_PF_FLAGS_ENABLE);
+
+	return ret >= 0 ? 0 : ret;
+}
+
 struct pf_frame {
 	struct pf_frame *next;
 	u32 key;
@@ -1747,7 +1828,6 @@ static void destroy_prefetch_work(struct prefetch_mr_work *work)
 {
 	struct mlx5_ib_dev *dev = to_mdev(pd->device);
 	struct mlx5_core_mkey *mmkey;
-	struct ib_umem_odp *odp;
 	struct mlx5_ib_mr *mr;
 
 	lockdep_assert_held(&dev->odp_srcu);
@@ -1761,11 +1841,9 @@ static void destroy_prefetch_work(struct prefetch_mr_work *work)
 	if (mr->ibmr.pd != pd)
 		return NULL;
 
-	odp = to_ib_umem_odp(mr->umem);
-
 	/* prefetch with write-access must be supported by the MR */
 	if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE &&
-	    !odp->umem.writable)
+	    !mr->umem->writable)
 		return NULL;
 
 	return mr;
-- 
1.8.3.1

_______________________________________________
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dri-devel@lists.freedesktop.org
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^ permalink raw reply related	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-07 22:15   ` Jianxin Xiong
@ 2020-12-08  7:05     ` Leon Romanovsky
  -1 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08  7:05 UTC (permalink / raw)
  To: Jianxin Xiong
  Cc: linux-rdma, dri-devel, Doug Ledford, Jason Gunthorpe,
	Sumit Semwal, Christian Koenig, Daniel Vetter

On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> Dma-buf is a standard cross-driver buffer sharing mechanism that can be
> used to support peer-to-peer access from RDMA devices.
>
> Device memory exported via dma-buf is associated with a file descriptor.
> This is passed to the user space as a property associated with the
> buffer allocation. When the buffer is registered as a memory region,
> the file descriptor is passed to the RDMA driver along with other
> parameters.
>
> Implement the common code for importing dma-buf object and mapping
> dma-buf pages.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Acked-by: Christian Koenig <christian.koenig@amd.com>
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
> Conflicts:
> 	include/rdma/ib_umem.h

This probably leftover from rebase, am I right?

> ---
>  drivers/infiniband/core/Makefile      |   2 +-
>  drivers/infiniband/core/umem.c        |   3 +
>  drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
>  include/rdma/ib_umem.h                |  43 ++++++++-
>  4 files changed, 219 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/infiniband/core/umem_dmabuf.c
>
> diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
> index ccf2670..8ab4eea 100644
> --- a/drivers/infiniband/core/Makefile
> +++ b/drivers/infiniband/core/Makefile
> @@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
>  				uverbs_std_types_srq.o \
>  				uverbs_std_types_wq.o \
>  				uverbs_std_types_qp.o
> -ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
> +ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
>  ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o
> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> index 7ca4112..cc131f8 100644
> --- a/drivers/infiniband/core/umem.c
> +++ b/drivers/infiniband/core/umem.c
> @@ -2,6 +2,7 @@
>   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
>   * Copyright (c) 2005 Cisco Systems.  All rights reserved.
>   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2020 Intel Corporation. All rights reserved.
>   *
>   * This software is available to you under a choice of one of two
>   * licenses.  You may choose to be licensed under the terms of the GNU
> @@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)
>  {
>  	if (!umem)
>  		return;
> +	if (umem->is_dmabuf)
> +		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
>  	if (umem->is_odp)
>  		return ib_umem_odp_release(to_ib_umem_odp(umem));
>
> diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
> new file mode 100644
> index 0000000..e50b955
> --- /dev/null
> +++ b/drivers/infiniband/core/umem_dmabuf.c
> @@ -0,0 +1,173 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> +/*
> + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> + */
> +
> +#include <linux/dma-buf.h>
> +#include <linux/dma-resv.h>
> +#include <linux/dma-mapping.h>
> +
> +#include "uverbs.h"
> +
> +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	struct sg_table *sgt;
> +	struct scatterlist *sg;
> +	struct dma_fence *fence;
> +	unsigned long start, end, cur;
> +	unsigned int nmap;
> +	int i;
> +
> +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> +
> +	if (umem_dmabuf->sgt)
> +		return 0;
> +
> +	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
> +	if (IS_ERR(sgt))
> +		return PTR_ERR(sgt);
> +
> +	/* modify the sg list in-place to match umem address and length */
> +
> +	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
> +	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
> +		    PAGE_SIZE);
> +	cur = 0;
> +	nmap = 0;

Better to put as part of variable initialization.

> +	for_each_sgtable_dma_sg(sgt, sg, i) {
> +		if (start < cur + sg_dma_len(sg) && cur < end)
> +			nmap++;
> +		if (cur <= start && start < cur + sg_dma_len(sg)) {
> +			unsigned long offset = start - cur;
> +
> +			umem_dmabuf->first_sg = sg;
> +			umem_dmabuf->first_sg_offset = offset;
> +			sg_dma_address(sg) += offset;
> +			sg_dma_len(sg) -= offset;
> +			cur += offset;
> +		}
> +		if (cur < end && end <= cur + sg_dma_len(sg)) {
> +			unsigned long trim = cur + sg_dma_len(sg) - end;
> +
> +			umem_dmabuf->last_sg = sg;
> +			umem_dmabuf->last_sg_trim = trim;
> +			sg_dma_len(sg) -= trim;
> +			break;
> +		}
> +		cur += sg_dma_len(sg);
> +	}
> +
> +	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
> +	umem_dmabuf->umem.sg_head.nents = nmap;
> +	umem_dmabuf->umem.nmap = nmap;
> +	umem_dmabuf->sgt = sgt;
> +
> +	/*
> +	 * Although the sg list is valid now, the content of the pages
> +	 * may be not up-to-date. Wait for the exporter to finish
> +	 * the migration.
> +	 */
> +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> +	if (fence)
> +		dma_fence_wait(fence, false);

Any reason do not check return result from dma_fence_wait()?

> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
> +
> +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> +
> +	if (!umem_dmabuf->sgt)
> +		return;
> +
> +	/* retore the original sg list */
> +	if (umem_dmabuf->first_sg) {
> +		sg_dma_address(umem_dmabuf->first_sg) -=
> +			umem_dmabuf->first_sg_offset;
> +		sg_dma_len(umem_dmabuf->first_sg) +=
> +			umem_dmabuf->first_sg_offset;
> +		umem_dmabuf->first_sg = NULL;
> +		umem_dmabuf->first_sg_offset = 0;
> +	}
> +	if (umem_dmabuf->last_sg) {
> +		sg_dma_len(umem_dmabuf->last_sg) +=
> +			umem_dmabuf->last_sg_trim;
> +		umem_dmabuf->last_sg = NULL;
> +		umem_dmabuf->last_sg_trim = 0;
> +	}
> +
> +	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
> +				 DMA_BIDIRECTIONAL);
> +
> +	umem_dmabuf->sgt = NULL;
> +}
> +EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
> +
> +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> +				   unsigned long offset, size_t size,
> +				   int fd, int access,
> +				   const struct dma_buf_attach_ops *ops)
> +{
> +	struct dma_buf *dmabuf;
> +	struct ib_umem_dmabuf *umem_dmabuf;
> +	struct ib_umem *umem;
> +	unsigned long end;
> +	long ret = -EINVAL;

It is wrong type for the returned value. One of the possible options
is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
ret = ERR_CAST(dmabuf);

> +
> +	if (check_add_overflow(offset, (unsigned long)size, &end))
> +		return ERR_PTR(-EINVAL);
> +
> +	if (unlikely(!ops || !ops->move_notify))

Let's not put likely/unlikely in control paths.

> +		return ERR_PTR(-EINVAL);
> +
> +	dmabuf = dma_buf_get(fd);
> +	if (IS_ERR(dmabuf))
> +		return (void *)dmabuf;

return ERR_CAST(dmabuf);

> +
> +	if (dmabuf->size < end)
> +		goto out_release_dmabuf;
> +
> +	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
> +	if (!umem_dmabuf)
> +		return ERR_PTR(-ENOMEM);

You are leaking dmabuf here, forgot to call to dma_buf_put();

> +
> +	umem = &umem_dmabuf->umem;
> +	umem->ibdev = device;
> +	umem->length = size;
> +	umem->address = offset;
> +	umem->writable = ib_access_writable(access);
> +	umem->is_dmabuf = 1;
> +
> +	if (unlikely(!ib_umem_num_pages(umem)))

There is no advantage in "unlikely" here.

> +		goto out_free_umem;
> +
> +	umem_dmabuf->attach = dma_buf_dynamic_attach(
> +					dmabuf,
> +					device->dma_device,
> +					ops,
> +					umem_dmabuf);
> +	if (IS_ERR(umem_dmabuf->attach)) {
> +		ret = PTR_ERR(umem_dmabuf->attach);
> +		goto out_free_umem;
> +	}
> +	return umem;
> +
> +out_free_umem:
> +	kfree(umem_dmabuf);
> +
> +out_release_dmabuf:
> +	dma_buf_put(dmabuf);
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL(ib_umem_dmabuf_get);
> +
> +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
> +
> +	dma_buf_detach(dmabuf, umem_dmabuf->attach);
> +	dma_buf_put(dmabuf);
> +	kfree(umem_dmabuf);
> +}
> diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
> index 7752211..b49a96d 100644
> --- a/include/rdma/ib_umem.h
> +++ b/include/rdma/ib_umem.h
> @@ -1,6 +1,7 @@
>  /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
>  /*
>   * Copyright (c) 2007 Cisco Systems.  All rights reserved.
> + * Copyright (c) 2020 Intel Corporation.  All rights reserved.
>   */
>
>  #ifndef IB_UMEM_H
> @@ -13,6 +14,7 @@
>
>  struct ib_ucontext;
>  struct ib_umem_odp;
> +struct dma_buf_attach_ops;
>
>  struct ib_umem {
>  	struct ib_device       *ibdev;
> @@ -22,12 +24,29 @@ struct ib_umem {
>  	unsigned long		address;
>  	u32 writable : 1;
>  	u32 is_odp : 1;
> +	u32 is_dmabuf : 1;
>  	struct work_struct	work;
>  	struct sg_table sg_head;
>  	int             nmap;
>  	unsigned int    sg_nents;
>  };
>
> +struct ib_umem_dmabuf {
> +	struct ib_umem umem;
> +	struct dma_buf_attachment *attach;
> +	struct sg_table *sgt;
> +	struct scatterlist *first_sg;
> +	struct scatterlist *last_sg;
> +	unsigned long first_sg_offset;
> +	unsigned long last_sg_trim;
> +	void *private;
> +};
> +
> +static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
> +{
> +	return container_of(umem, struct ib_umem_dmabuf, umem);
> +}
> +
>  /* Returns the offset of the umem start relative to the first page. */
>  static inline int ib_umem_offset(struct ib_umem *umem)
>  {
> @@ -86,6 +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
>  unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
>  				     unsigned long pgsz_bitmap,
>  				     unsigned long virt);
> +
>  /**
>   * ib_umem_find_best_pgoff - Find best HW page size
>   *
> @@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
>  				      dma_addr & pgoff_bitmask);
>  }
>
> +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> +				   unsigned long offset, size_t size,
> +				   int fd, int access,
> +				   const struct dma_buf_attach_ops *ops);
> +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
> +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
> +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
> +
>  #else /* CONFIG_INFINIBAND_USER_MEM */
>
>  #include <linux/err.h>
> @@ -143,7 +171,20 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
>  {
>  	return 0;
>  }
> +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> +						 unsigned long offset,
> +						 size_t size, int fd,
> +						 int access,
> +						 struct dma_buf_attach_ops *ops)
> +{
> +	return ERR_PTR(-EINVAL);

Probably, It should be EOPNOTSUPP and not EINVAL.

> +}
> +static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	return -EINVAL;
> +}
> +static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
> +static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
>
>  #endif /* CONFIG_INFINIBAND_USER_MEM */
> -
>  #endif /* IB_UMEM_H */
> --
> 1.8.3.1
>

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-08  7:05     ` Leon Romanovsky
  0 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08  7:05 UTC (permalink / raw)
  To: Jianxin Xiong
  Cc: linux-rdma, dri-devel, Christian Koenig, Jason Gunthorpe,
	Doug Ledford, Daniel Vetter

On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> Dma-buf is a standard cross-driver buffer sharing mechanism that can be
> used to support peer-to-peer access from RDMA devices.
>
> Device memory exported via dma-buf is associated with a file descriptor.
> This is passed to the user space as a property associated with the
> buffer allocation. When the buffer is registered as a memory region,
> the file descriptor is passed to the RDMA driver along with other
> parameters.
>
> Implement the common code for importing dma-buf object and mapping
> dma-buf pages.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Acked-by: Christian Koenig <christian.koenig@amd.com>
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
> Conflicts:
> 	include/rdma/ib_umem.h

This probably leftover from rebase, am I right?

> ---
>  drivers/infiniband/core/Makefile      |   2 +-
>  drivers/infiniband/core/umem.c        |   3 +
>  drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
>  include/rdma/ib_umem.h                |  43 ++++++++-
>  4 files changed, 219 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/infiniband/core/umem_dmabuf.c
>
> diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
> index ccf2670..8ab4eea 100644
> --- a/drivers/infiniband/core/Makefile
> +++ b/drivers/infiniband/core/Makefile
> @@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
>  				uverbs_std_types_srq.o \
>  				uverbs_std_types_wq.o \
>  				uverbs_std_types_qp.o
> -ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
> +ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
>  ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o
> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> index 7ca4112..cc131f8 100644
> --- a/drivers/infiniband/core/umem.c
> +++ b/drivers/infiniband/core/umem.c
> @@ -2,6 +2,7 @@
>   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
>   * Copyright (c) 2005 Cisco Systems.  All rights reserved.
>   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2020 Intel Corporation. All rights reserved.
>   *
>   * This software is available to you under a choice of one of two
>   * licenses.  You may choose to be licensed under the terms of the GNU
> @@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)
>  {
>  	if (!umem)
>  		return;
> +	if (umem->is_dmabuf)
> +		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
>  	if (umem->is_odp)
>  		return ib_umem_odp_release(to_ib_umem_odp(umem));
>
> diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
> new file mode 100644
> index 0000000..e50b955
> --- /dev/null
> +++ b/drivers/infiniband/core/umem_dmabuf.c
> @@ -0,0 +1,173 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> +/*
> + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> + */
> +
> +#include <linux/dma-buf.h>
> +#include <linux/dma-resv.h>
> +#include <linux/dma-mapping.h>
> +
> +#include "uverbs.h"
> +
> +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	struct sg_table *sgt;
> +	struct scatterlist *sg;
> +	struct dma_fence *fence;
> +	unsigned long start, end, cur;
> +	unsigned int nmap;
> +	int i;
> +
> +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> +
> +	if (umem_dmabuf->sgt)
> +		return 0;
> +
> +	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
> +	if (IS_ERR(sgt))
> +		return PTR_ERR(sgt);
> +
> +	/* modify the sg list in-place to match umem address and length */
> +
> +	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
> +	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
> +		    PAGE_SIZE);
> +	cur = 0;
> +	nmap = 0;

Better to put as part of variable initialization.

> +	for_each_sgtable_dma_sg(sgt, sg, i) {
> +		if (start < cur + sg_dma_len(sg) && cur < end)
> +			nmap++;
> +		if (cur <= start && start < cur + sg_dma_len(sg)) {
> +			unsigned long offset = start - cur;
> +
> +			umem_dmabuf->first_sg = sg;
> +			umem_dmabuf->first_sg_offset = offset;
> +			sg_dma_address(sg) += offset;
> +			sg_dma_len(sg) -= offset;
> +			cur += offset;
> +		}
> +		if (cur < end && end <= cur + sg_dma_len(sg)) {
> +			unsigned long trim = cur + sg_dma_len(sg) - end;
> +
> +			umem_dmabuf->last_sg = sg;
> +			umem_dmabuf->last_sg_trim = trim;
> +			sg_dma_len(sg) -= trim;
> +			break;
> +		}
> +		cur += sg_dma_len(sg);
> +	}
> +
> +	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
> +	umem_dmabuf->umem.sg_head.nents = nmap;
> +	umem_dmabuf->umem.nmap = nmap;
> +	umem_dmabuf->sgt = sgt;
> +
> +	/*
> +	 * Although the sg list is valid now, the content of the pages
> +	 * may be not up-to-date. Wait for the exporter to finish
> +	 * the migration.
> +	 */
> +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> +	if (fence)
> +		dma_fence_wait(fence, false);

Any reason do not check return result from dma_fence_wait()?

> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
> +
> +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> +
> +	if (!umem_dmabuf->sgt)
> +		return;
> +
> +	/* retore the original sg list */
> +	if (umem_dmabuf->first_sg) {
> +		sg_dma_address(umem_dmabuf->first_sg) -=
> +			umem_dmabuf->first_sg_offset;
> +		sg_dma_len(umem_dmabuf->first_sg) +=
> +			umem_dmabuf->first_sg_offset;
> +		umem_dmabuf->first_sg = NULL;
> +		umem_dmabuf->first_sg_offset = 0;
> +	}
> +	if (umem_dmabuf->last_sg) {
> +		sg_dma_len(umem_dmabuf->last_sg) +=
> +			umem_dmabuf->last_sg_trim;
> +		umem_dmabuf->last_sg = NULL;
> +		umem_dmabuf->last_sg_trim = 0;
> +	}
> +
> +	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
> +				 DMA_BIDIRECTIONAL);
> +
> +	umem_dmabuf->sgt = NULL;
> +}
> +EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
> +
> +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> +				   unsigned long offset, size_t size,
> +				   int fd, int access,
> +				   const struct dma_buf_attach_ops *ops)
> +{
> +	struct dma_buf *dmabuf;
> +	struct ib_umem_dmabuf *umem_dmabuf;
> +	struct ib_umem *umem;
> +	unsigned long end;
> +	long ret = -EINVAL;

It is wrong type for the returned value. One of the possible options
is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
ret = ERR_CAST(dmabuf);

> +
> +	if (check_add_overflow(offset, (unsigned long)size, &end))
> +		return ERR_PTR(-EINVAL);
> +
> +	if (unlikely(!ops || !ops->move_notify))

Let's not put likely/unlikely in control paths.

> +		return ERR_PTR(-EINVAL);
> +
> +	dmabuf = dma_buf_get(fd);
> +	if (IS_ERR(dmabuf))
> +		return (void *)dmabuf;

return ERR_CAST(dmabuf);

> +
> +	if (dmabuf->size < end)
> +		goto out_release_dmabuf;
> +
> +	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
> +	if (!umem_dmabuf)
> +		return ERR_PTR(-ENOMEM);

You are leaking dmabuf here, forgot to call to dma_buf_put();

> +
> +	umem = &umem_dmabuf->umem;
> +	umem->ibdev = device;
> +	umem->length = size;
> +	umem->address = offset;
> +	umem->writable = ib_access_writable(access);
> +	umem->is_dmabuf = 1;
> +
> +	if (unlikely(!ib_umem_num_pages(umem)))

There is no advantage in "unlikely" here.

> +		goto out_free_umem;
> +
> +	umem_dmabuf->attach = dma_buf_dynamic_attach(
> +					dmabuf,
> +					device->dma_device,
> +					ops,
> +					umem_dmabuf);
> +	if (IS_ERR(umem_dmabuf->attach)) {
> +		ret = PTR_ERR(umem_dmabuf->attach);
> +		goto out_free_umem;
> +	}
> +	return umem;
> +
> +out_free_umem:
> +	kfree(umem_dmabuf);
> +
> +out_release_dmabuf:
> +	dma_buf_put(dmabuf);
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL(ib_umem_dmabuf_get);
> +
> +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
> +
> +	dma_buf_detach(dmabuf, umem_dmabuf->attach);
> +	dma_buf_put(dmabuf);
> +	kfree(umem_dmabuf);
> +}
> diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
> index 7752211..b49a96d 100644
> --- a/include/rdma/ib_umem.h
> +++ b/include/rdma/ib_umem.h
> @@ -1,6 +1,7 @@
>  /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
>  /*
>   * Copyright (c) 2007 Cisco Systems.  All rights reserved.
> + * Copyright (c) 2020 Intel Corporation.  All rights reserved.
>   */
>
>  #ifndef IB_UMEM_H
> @@ -13,6 +14,7 @@
>
>  struct ib_ucontext;
>  struct ib_umem_odp;
> +struct dma_buf_attach_ops;
>
>  struct ib_umem {
>  	struct ib_device       *ibdev;
> @@ -22,12 +24,29 @@ struct ib_umem {
>  	unsigned long		address;
>  	u32 writable : 1;
>  	u32 is_odp : 1;
> +	u32 is_dmabuf : 1;
>  	struct work_struct	work;
>  	struct sg_table sg_head;
>  	int             nmap;
>  	unsigned int    sg_nents;
>  };
>
> +struct ib_umem_dmabuf {
> +	struct ib_umem umem;
> +	struct dma_buf_attachment *attach;
> +	struct sg_table *sgt;
> +	struct scatterlist *first_sg;
> +	struct scatterlist *last_sg;
> +	unsigned long first_sg_offset;
> +	unsigned long last_sg_trim;
> +	void *private;
> +};
> +
> +static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
> +{
> +	return container_of(umem, struct ib_umem_dmabuf, umem);
> +}
> +
>  /* Returns the offset of the umem start relative to the first page. */
>  static inline int ib_umem_offset(struct ib_umem *umem)
>  {
> @@ -86,6 +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
>  unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
>  				     unsigned long pgsz_bitmap,
>  				     unsigned long virt);
> +
>  /**
>   * ib_umem_find_best_pgoff - Find best HW page size
>   *
> @@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
>  				      dma_addr & pgoff_bitmask);
>  }
>
> +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> +				   unsigned long offset, size_t size,
> +				   int fd, int access,
> +				   const struct dma_buf_attach_ops *ops);
> +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
> +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
> +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
> +
>  #else /* CONFIG_INFINIBAND_USER_MEM */
>
>  #include <linux/err.h>
> @@ -143,7 +171,20 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
>  {
>  	return 0;
>  }
> +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> +						 unsigned long offset,
> +						 size_t size, int fd,
> +						 int access,
> +						 struct dma_buf_attach_ops *ops)
> +{
> +	return ERR_PTR(-EINVAL);

Probably, It should be EOPNOTSUPP and not EINVAL.

> +}
> +static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
> +{
> +	return -EINVAL;
> +}
> +static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
> +static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
>
>  #endif /* CONFIG_INFINIBAND_USER_MEM */
> -
>  #endif /* IB_UMEM_H */
> --
> 1.8.3.1
>
_______________________________________________
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dri-devel@lists.freedesktop.org
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^ permalink raw reply	[flat|nested] 26+ messages in thread
* RE: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-08  7:05     ` Leon Romanovsky
@ 2020-12-08  7:10       ` Xiong, Jianxin
  -1 siblings, 0 replies; 26+ messages in thread
From: Xiong, Jianxin @ 2020-12-08  7:10 UTC (permalink / raw)
  To: Leon Romanovsky
  Cc: linux-rdma, dri-devel, Doug Ledford, Jason Gunthorpe,
	Sumit Semwal, Christian Koenig, Vetter, Daniel

> -----Original Message-----
> From: Leon Romanovsky <leon@kernel.org>
> Sent: Monday, December 07, 2020 11:06 PM
> To: Xiong, Jianxin <jianxin.xiong@intel.com>
> Cc: linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel <daniel.vetter@intel.com>
> Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> 
> On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> > Dma-buf is a standard cross-driver buffer sharing mechanism that can
> > be used to support peer-to-peer access from RDMA devices.
> >
> > Device memory exported via dma-buf is associated with a file descriptor.
> > This is passed to the user space as a property associated with the
> > buffer allocation. When the buffer is registered as a memory region,
> > the file descriptor is passed to the RDMA driver along with other
> > parameters.
> >
> > Implement the common code for importing dma-buf object and mapping
> > dma-buf pages.
> >
> > Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> > Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> > Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > Acked-by: Christian Koenig <christian.koenig@amd.com>
> > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> >
> > Conflicts:
> > 	include/rdma/ib_umem.h
> 
> This probably leftover from rebase, am I right?

Right. Should have removed it.

> 
> > ---
> >  drivers/infiniband/core/Makefile      |   2 +-
> >  drivers/infiniband/core/umem.c        |   3 +
> >  drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
> >  include/rdma/ib_umem.h                |  43 ++++++++-
> >  4 files changed, 219 insertions(+), 2 deletions(-)  create mode
> > 100644 drivers/infiniband/core/umem_dmabuf.c
> >
> > diff --git a/drivers/infiniband/core/Makefile
> > b/drivers/infiniband/core/Makefile
> > index ccf2670..8ab4eea 100644
> > --- a/drivers/infiniband/core/Makefile
> > +++ b/drivers/infiniband/core/Makefile
> > @@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
> >  				uverbs_std_types_srq.o \
> >  				uverbs_std_types_wq.o \
> >  				uverbs_std_types_qp.o
> > -ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
> > +ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
> >  ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o diff
> > --git a/drivers/infiniband/core/umem.c
> > b/drivers/infiniband/core/umem.c index 7ca4112..cc131f8 100644
> > --- a/drivers/infiniband/core/umem.c
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -2,6 +2,7 @@
> >   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
> >   * Copyright (c) 2005 Cisco Systems.  All rights reserved.
> >   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> >   *
> >   * This software is available to you under a choice of one of two
> >   * licenses.  You may choose to be licensed under the terms of the
> > GNU @@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)  {
> >  	if (!umem)
> >  		return;
> > +	if (umem->is_dmabuf)
> > +		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
> >  	if (umem->is_odp)
> >  		return ib_umem_odp_release(to_ib_umem_odp(umem));
> >
> > diff --git a/drivers/infiniband/core/umem_dmabuf.c
> > b/drivers/infiniband/core/umem_dmabuf.c
> > new file mode 100644
> > index 0000000..e50b955
> > --- /dev/null
> > +++ b/drivers/infiniband/core/umem_dmabuf.c
> > @@ -0,0 +1,173 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> > + */
> > +
> > +#include <linux/dma-buf.h>
> > +#include <linux/dma-resv.h>
> > +#include <linux/dma-mapping.h>
> > +
> > +#include "uverbs.h"
> > +
> > +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct sg_table *sgt;
> > +	struct scatterlist *sg;
> > +	struct dma_fence *fence;
> > +	unsigned long start, end, cur;
> > +	unsigned int nmap;
> > +	int i;
> > +
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (umem_dmabuf->sgt)
> > +		return 0;
> > +
> > +	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
> > +	if (IS_ERR(sgt))
> > +		return PTR_ERR(sgt);
> > +
> > +	/* modify the sg list in-place to match umem address and length */
> > +
> > +	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
> > +	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
> > +		    PAGE_SIZE);
> > +	cur = 0;
> > +	nmap = 0;
> 
> Better to put as part of variable initialization.
> 
> > +	for_each_sgtable_dma_sg(sgt, sg, i) {
> > +		if (start < cur + sg_dma_len(sg) && cur < end)
> > +			nmap++;
> > +		if (cur <= start && start < cur + sg_dma_len(sg)) {
> > +			unsigned long offset = start - cur;
> > +
> > +			umem_dmabuf->first_sg = sg;
> > +			umem_dmabuf->first_sg_offset = offset;
> > +			sg_dma_address(sg) += offset;
> > +			sg_dma_len(sg) -= offset;
> > +			cur += offset;
> > +		}
> > +		if (cur < end && end <= cur + sg_dma_len(sg)) {
> > +			unsigned long trim = cur + sg_dma_len(sg) - end;
> > +
> > +			umem_dmabuf->last_sg = sg;
> > +			umem_dmabuf->last_sg_trim = trim;
> > +			sg_dma_len(sg) -= trim;
> > +			break;
> > +		}
> > +		cur += sg_dma_len(sg);
> > +	}
> > +
> > +	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
> > +	umem_dmabuf->umem.sg_head.nents = nmap;
> > +	umem_dmabuf->umem.nmap = nmap;
> > +	umem_dmabuf->sgt = sgt;
> > +
> > +	/*
> > +	 * Although the sg list is valid now, the content of the pages
> > +	 * may be not up-to-date. Wait for the exporter to finish
> > +	 * the migration.
> > +	 */
> > +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> > +	if (fence)
> > +		dma_fence_wait(fence, false);
> 
> Any reason do not check return result from dma_fence_wait()?
> 
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
> > +
> > +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (!umem_dmabuf->sgt)
> > +		return;
> > +
> > +	/* retore the original sg list */
> > +	if (umem_dmabuf->first_sg) {
> > +		sg_dma_address(umem_dmabuf->first_sg) -=
> > +			umem_dmabuf->first_sg_offset;
> > +		sg_dma_len(umem_dmabuf->first_sg) +=
> > +			umem_dmabuf->first_sg_offset;
> > +		umem_dmabuf->first_sg = NULL;
> > +		umem_dmabuf->first_sg_offset = 0;
> > +	}
> > +	if (umem_dmabuf->last_sg) {
> > +		sg_dma_len(umem_dmabuf->last_sg) +=
> > +			umem_dmabuf->last_sg_trim;
> > +		umem_dmabuf->last_sg = NULL;
> > +		umem_dmabuf->last_sg_trim = 0;
> > +	}
> > +
> > +	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
> > +				 DMA_BIDIRECTIONAL);
> > +
> > +	umem_dmabuf->sgt = NULL;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
> > +
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops) {
> > +	struct dma_buf *dmabuf;
> > +	struct ib_umem_dmabuf *umem_dmabuf;
> > +	struct ib_umem *umem;
> > +	unsigned long end;
> > +	long ret = -EINVAL;
> 
> It is wrong type for the returned value. One of the possible options is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
> ret = ERR_CAST(dmabuf);
> 
> > +
> > +	if (check_add_overflow(offset, (unsigned long)size, &end))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	if (unlikely(!ops || !ops->move_notify))
> 
> Let's not put likely/unlikely in control paths.
> 
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	dmabuf = dma_buf_get(fd);
> > +	if (IS_ERR(dmabuf))
> > +		return (void *)dmabuf;
> 
> return ERR_CAST(dmabuf);
> 
> > +
> > +	if (dmabuf->size < end)
> > +		goto out_release_dmabuf;
> > +
> > +	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
> > +	if (!umem_dmabuf)
> > +		return ERR_PTR(-ENOMEM);
> 
> You are leaking dmabuf here, forgot to call to dma_buf_put();
> 
> > +
> > +	umem = &umem_dmabuf->umem;
> > +	umem->ibdev = device;
> > +	umem->length = size;
> > +	umem->address = offset;
> > +	umem->writable = ib_access_writable(access);
> > +	umem->is_dmabuf = 1;
> > +
> > +	if (unlikely(!ib_umem_num_pages(umem)))
> 
> There is no advantage in "unlikely" here.
> 
> > +		goto out_free_umem;
> > +
> > +	umem_dmabuf->attach = dma_buf_dynamic_attach(
> > +					dmabuf,
> > +					device->dma_device,
> > +					ops,
> > +					umem_dmabuf);
> > +	if (IS_ERR(umem_dmabuf->attach)) {
> > +		ret = PTR_ERR(umem_dmabuf->attach);
> > +		goto out_free_umem;
> > +	}
> > +	return umem;
> > +
> > +out_free_umem:
> > +	kfree(umem_dmabuf);
> > +
> > +out_release_dmabuf:
> > +	dma_buf_put(dmabuf);
> > +	return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_get);
> > +
> > +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
> > +
> > +	dma_buf_detach(dmabuf, umem_dmabuf->attach);
> > +	dma_buf_put(dmabuf);
> > +	kfree(umem_dmabuf);
> > +}
> > diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index
> > 7752211..b49a96d 100644
> > --- a/include/rdma/ib_umem.h
> > +++ b/include/rdma/ib_umem.h
> > @@ -1,6 +1,7 @@
> >  /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
> >  /*
> >   * Copyright (c) 2007 Cisco Systems.  All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation.  All rights reserved.
> >   */
> >
> >  #ifndef IB_UMEM_H
> > @@ -13,6 +14,7 @@
> >
> >  struct ib_ucontext;
> >  struct ib_umem_odp;
> > +struct dma_buf_attach_ops;
> >
> >  struct ib_umem {
> >  	struct ib_device       *ibdev;
> > @@ -22,12 +24,29 @@ struct ib_umem {
> >  	unsigned long		address;
> >  	u32 writable : 1;
> >  	u32 is_odp : 1;
> > +	u32 is_dmabuf : 1;
> >  	struct work_struct	work;
> >  	struct sg_table sg_head;
> >  	int             nmap;
> >  	unsigned int    sg_nents;
> >  };
> >
> > +struct ib_umem_dmabuf {
> > +	struct ib_umem umem;
> > +	struct dma_buf_attachment *attach;
> > +	struct sg_table *sgt;
> > +	struct scatterlist *first_sg;
> > +	struct scatterlist *last_sg;
> > +	unsigned long first_sg_offset;
> > +	unsigned long last_sg_trim;
> > +	void *private;
> > +};
> > +
> > +static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem
> > +*umem) {
> > +	return container_of(umem, struct ib_umem_dmabuf, umem); }
> > +
> >  /* Returns the offset of the umem start relative to the first page.
> > */  static inline int ib_umem_offset(struct ib_umem *umem)  { @@ -86,6
> > +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem,
> > size_t offset,  unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
> >  				     unsigned long pgsz_bitmap,
> >  				     unsigned long virt);
> > +
> >  /**
> >   * ib_umem_find_best_pgoff - Find best HW page size
> >   *
> > @@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
> >  				      dma_addr & pgoff_bitmask);
> >  }
> >
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops); int
> > +ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
> > +
> >  #else /* CONFIG_INFINIBAND_USER_MEM */
> >
> >  #include <linux/err.h>
> > @@ -143,7 +171,20 @@ static inline unsigned long
> > ib_umem_find_best_pgoff(struct ib_umem *umem,  {
> >  	return 0;
> >  }
> > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +						 unsigned long offset,
> > +						 size_t size, int fd,
> > +						 int access,
> > +						 struct dma_buf_attach_ops *ops) {
> > +	return ERR_PTR(-EINVAL);
> 
> Probably, It should be EOPNOTSUPP and not EINVAL.
> 
> > +}
> > +static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) {
> > +	return -EINVAL;
> > +}
> > +static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) { } static inline void ib_umem_dmabuf_release(struct
> > +ib_umem_dmabuf *umem_dmabuf) { }
> >
> >  #endif /* CONFIG_INFINIBAND_USER_MEM */
> > -
> >  #endif /* IB_UMEM_H */
> > --
> > 1.8.3.1
> >

^ permalink raw reply	[flat|nested] 26+ messages in thread
* RE: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-08  7:10       ` Xiong, Jianxin
  0 siblings, 0 replies; 26+ messages in thread
From: Xiong, Jianxin @ 2020-12-08  7:10 UTC (permalink / raw)
  To: Leon Romanovsky
  Cc: linux-rdma, dri-devel, Christian Koenig, Jason Gunthorpe,
	Doug Ledford, Vetter, Daniel

> -----Original Message-----
> From: Leon Romanovsky <leon@kernel.org>
> Sent: Monday, December 07, 2020 11:06 PM
> To: Xiong, Jianxin <jianxin.xiong@intel.com>
> Cc: linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel <daniel.vetter@intel.com>
> Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> 
> On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> > Dma-buf is a standard cross-driver buffer sharing mechanism that can
> > be used to support peer-to-peer access from RDMA devices.
> >
> > Device memory exported via dma-buf is associated with a file descriptor.
> > This is passed to the user space as a property associated with the
> > buffer allocation. When the buffer is registered as a memory region,
> > the file descriptor is passed to the RDMA driver along with other
> > parameters.
> >
> > Implement the common code for importing dma-buf object and mapping
> > dma-buf pages.
> >
> > Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> > Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> > Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > Acked-by: Christian Koenig <christian.koenig@amd.com>
> > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> >
> > Conflicts:
> > 	include/rdma/ib_umem.h
> 
> This probably leftover from rebase, am I right?

Right. Should have removed it.

> 
> > ---
> >  drivers/infiniband/core/Makefile      |   2 +-
> >  drivers/infiniband/core/umem.c        |   3 +
> >  drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
> >  include/rdma/ib_umem.h                |  43 ++++++++-
> >  4 files changed, 219 insertions(+), 2 deletions(-)  create mode
> > 100644 drivers/infiniband/core/umem_dmabuf.c
> >
> > diff --git a/drivers/infiniband/core/Makefile
> > b/drivers/infiniband/core/Makefile
> > index ccf2670..8ab4eea 100644
> > --- a/drivers/infiniband/core/Makefile
> > +++ b/drivers/infiniband/core/Makefile
> > @@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
> >  				uverbs_std_types_srq.o \
> >  				uverbs_std_types_wq.o \
> >  				uverbs_std_types_qp.o
> > -ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
> > +ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
> >  ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o diff
> > --git a/drivers/infiniband/core/umem.c
> > b/drivers/infiniband/core/umem.c index 7ca4112..cc131f8 100644
> > --- a/drivers/infiniband/core/umem.c
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -2,6 +2,7 @@
> >   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
> >   * Copyright (c) 2005 Cisco Systems.  All rights reserved.
> >   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> >   *
> >   * This software is available to you under a choice of one of two
> >   * licenses.  You may choose to be licensed under the terms of the
> > GNU @@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)  {
> >  	if (!umem)
> >  		return;
> > +	if (umem->is_dmabuf)
> > +		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
> >  	if (umem->is_odp)
> >  		return ib_umem_odp_release(to_ib_umem_odp(umem));
> >
> > diff --git a/drivers/infiniband/core/umem_dmabuf.c
> > b/drivers/infiniband/core/umem_dmabuf.c
> > new file mode 100644
> > index 0000000..e50b955
> > --- /dev/null
> > +++ b/drivers/infiniband/core/umem_dmabuf.c
> > @@ -0,0 +1,173 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> > + */
> > +
> > +#include <linux/dma-buf.h>
> > +#include <linux/dma-resv.h>
> > +#include <linux/dma-mapping.h>
> > +
> > +#include "uverbs.h"
> > +
> > +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct sg_table *sgt;
> > +	struct scatterlist *sg;
> > +	struct dma_fence *fence;
> > +	unsigned long start, end, cur;
> > +	unsigned int nmap;
> > +	int i;
> > +
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (umem_dmabuf->sgt)
> > +		return 0;
> > +
> > +	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
> > +	if (IS_ERR(sgt))
> > +		return PTR_ERR(sgt);
> > +
> > +	/* modify the sg list in-place to match umem address and length */
> > +
> > +	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
> > +	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
> > +		    PAGE_SIZE);
> > +	cur = 0;
> > +	nmap = 0;
> 
> Better to put as part of variable initialization.
> 
> > +	for_each_sgtable_dma_sg(sgt, sg, i) {
> > +		if (start < cur + sg_dma_len(sg) && cur < end)
> > +			nmap++;
> > +		if (cur <= start && start < cur + sg_dma_len(sg)) {
> > +			unsigned long offset = start - cur;
> > +
> > +			umem_dmabuf->first_sg = sg;
> > +			umem_dmabuf->first_sg_offset = offset;
> > +			sg_dma_address(sg) += offset;
> > +			sg_dma_len(sg) -= offset;
> > +			cur += offset;
> > +		}
> > +		if (cur < end && end <= cur + sg_dma_len(sg)) {
> > +			unsigned long trim = cur + sg_dma_len(sg) - end;
> > +
> > +			umem_dmabuf->last_sg = sg;
> > +			umem_dmabuf->last_sg_trim = trim;
> > +			sg_dma_len(sg) -= trim;
> > +			break;
> > +		}
> > +		cur += sg_dma_len(sg);
> > +	}
> > +
> > +	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
> > +	umem_dmabuf->umem.sg_head.nents = nmap;
> > +	umem_dmabuf->umem.nmap = nmap;
> > +	umem_dmabuf->sgt = sgt;
> > +
> > +	/*
> > +	 * Although the sg list is valid now, the content of the pages
> > +	 * may be not up-to-date. Wait for the exporter to finish
> > +	 * the migration.
> > +	 */
> > +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> > +	if (fence)
> > +		dma_fence_wait(fence, false);
> 
> Any reason do not check return result from dma_fence_wait()?
> 
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
> > +
> > +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (!umem_dmabuf->sgt)
> > +		return;
> > +
> > +	/* retore the original sg list */
> > +	if (umem_dmabuf->first_sg) {
> > +		sg_dma_address(umem_dmabuf->first_sg) -=
> > +			umem_dmabuf->first_sg_offset;
> > +		sg_dma_len(umem_dmabuf->first_sg) +=
> > +			umem_dmabuf->first_sg_offset;
> > +		umem_dmabuf->first_sg = NULL;
> > +		umem_dmabuf->first_sg_offset = 0;
> > +	}
> > +	if (umem_dmabuf->last_sg) {
> > +		sg_dma_len(umem_dmabuf->last_sg) +=
> > +			umem_dmabuf->last_sg_trim;
> > +		umem_dmabuf->last_sg = NULL;
> > +		umem_dmabuf->last_sg_trim = 0;
> > +	}
> > +
> > +	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
> > +				 DMA_BIDIRECTIONAL);
> > +
> > +	umem_dmabuf->sgt = NULL;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
> > +
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops) {
> > +	struct dma_buf *dmabuf;
> > +	struct ib_umem_dmabuf *umem_dmabuf;
> > +	struct ib_umem *umem;
> > +	unsigned long end;
> > +	long ret = -EINVAL;
> 
> It is wrong type for the returned value. One of the possible options is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
> ret = ERR_CAST(dmabuf);
> 
> > +
> > +	if (check_add_overflow(offset, (unsigned long)size, &end))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	if (unlikely(!ops || !ops->move_notify))
> 
> Let's not put likely/unlikely in control paths.
> 
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	dmabuf = dma_buf_get(fd);
> > +	if (IS_ERR(dmabuf))
> > +		return (void *)dmabuf;
> 
> return ERR_CAST(dmabuf);
> 
> > +
> > +	if (dmabuf->size < end)
> > +		goto out_release_dmabuf;
> > +
> > +	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
> > +	if (!umem_dmabuf)
> > +		return ERR_PTR(-ENOMEM);
> 
> You are leaking dmabuf here, forgot to call to dma_buf_put();
> 
> > +
> > +	umem = &umem_dmabuf->umem;
> > +	umem->ibdev = device;
> > +	umem->length = size;
> > +	umem->address = offset;
> > +	umem->writable = ib_access_writable(access);
> > +	umem->is_dmabuf = 1;
> > +
> > +	if (unlikely(!ib_umem_num_pages(umem)))
> 
> There is no advantage in "unlikely" here.
> 
> > +		goto out_free_umem;
> > +
> > +	umem_dmabuf->attach = dma_buf_dynamic_attach(
> > +					dmabuf,
> > +					device->dma_device,
> > +					ops,
> > +					umem_dmabuf);
> > +	if (IS_ERR(umem_dmabuf->attach)) {
> > +		ret = PTR_ERR(umem_dmabuf->attach);
> > +		goto out_free_umem;
> > +	}
> > +	return umem;
> > +
> > +out_free_umem:
> > +	kfree(umem_dmabuf);
> > +
> > +out_release_dmabuf:
> > +	dma_buf_put(dmabuf);
> > +	return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_get);
> > +
> > +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
> > +
> > +	dma_buf_detach(dmabuf, umem_dmabuf->attach);
> > +	dma_buf_put(dmabuf);
> > +	kfree(umem_dmabuf);
> > +}
> > diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index
> > 7752211..b49a96d 100644
> > --- a/include/rdma/ib_umem.h
> > +++ b/include/rdma/ib_umem.h
> > @@ -1,6 +1,7 @@
> >  /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
> >  /*
> >   * Copyright (c) 2007 Cisco Systems.  All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation.  All rights reserved.
> >   */
> >
> >  #ifndef IB_UMEM_H
> > @@ -13,6 +14,7 @@
> >
> >  struct ib_ucontext;
> >  struct ib_umem_odp;
> > +struct dma_buf_attach_ops;
> >
> >  struct ib_umem {
> >  	struct ib_device       *ibdev;
> > @@ -22,12 +24,29 @@ struct ib_umem {
> >  	unsigned long		address;
> >  	u32 writable : 1;
> >  	u32 is_odp : 1;
> > +	u32 is_dmabuf : 1;
> >  	struct work_struct	work;
> >  	struct sg_table sg_head;
> >  	int             nmap;
> >  	unsigned int    sg_nents;
> >  };
> >
> > +struct ib_umem_dmabuf {
> > +	struct ib_umem umem;
> > +	struct dma_buf_attachment *attach;
> > +	struct sg_table *sgt;
> > +	struct scatterlist *first_sg;
> > +	struct scatterlist *last_sg;
> > +	unsigned long first_sg_offset;
> > +	unsigned long last_sg_trim;
> > +	void *private;
> > +};
> > +
> > +static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem
> > +*umem) {
> > +	return container_of(umem, struct ib_umem_dmabuf, umem); }
> > +
> >  /* Returns the offset of the umem start relative to the first page.
> > */  static inline int ib_umem_offset(struct ib_umem *umem)  { @@ -86,6
> > +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem,
> > size_t offset,  unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
> >  				     unsigned long pgsz_bitmap,
> >  				     unsigned long virt);
> > +
> >  /**
> >   * ib_umem_find_best_pgoff - Find best HW page size
> >   *
> > @@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
> >  				      dma_addr & pgoff_bitmask);
> >  }
> >
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops); int
> > +ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
> > +
> >  #else /* CONFIG_INFINIBAND_USER_MEM */
> >
> >  #include <linux/err.h>
> > @@ -143,7 +171,20 @@ static inline unsigned long
> > ib_umem_find_best_pgoff(struct ib_umem *umem,  {
> >  	return 0;
> >  }
> > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +						 unsigned long offset,
> > +						 size_t size, int fd,
> > +						 int access,
> > +						 struct dma_buf_attach_ops *ops) {
> > +	return ERR_PTR(-EINVAL);
> 
> Probably, It should be EOPNOTSUPP and not EINVAL.
> 
> > +}
> > +static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) {
> > +	return -EINVAL;
> > +}
> > +static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) { } static inline void ib_umem_dmabuf_release(struct
> > +ib_umem_dmabuf *umem_dmabuf) { }
> >
> >  #endif /* CONFIG_INFINIBAND_USER_MEM */
> > -
> >  #endif /* IB_UMEM_H */
> > --
> > 1.8.3.1
> >
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^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 2/4] RDMA/core: Add device method for registering dma-buf based memory region
  2020-12-07 22:15   ` Jianxin Xiong
@ 2020-12-08  7:12     ` Leon Romanovsky
  -1 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08  7:12 UTC (permalink / raw)
  To: Jianxin Xiong
  Cc: linux-rdma, dri-devel, Doug Ledford, Jason Gunthorpe,
	Sumit Semwal, Christian Koenig, Daniel Vetter

On Mon, Dec 07, 2020 at 02:15:51PM -0800, Jianxin Xiong wrote:
> Dma-buf based memory region requires one extra parameter and is processed
> quite differently. Adding a separate method allows clean separation from
> regular memory regions.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Acked-by: Christian Koenig <christian.koenig@amd.com>
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/infiniband/core/device.c | 1 +
>  include/rdma/ib_verbs.h          | 6 +++++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
>

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 2/4] RDMA/core: Add device method for registering dma-buf based memory region
@ 2020-12-08  7:12     ` Leon Romanovsky
  0 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08  7:12 UTC (permalink / raw)
  To: Jianxin Xiong
  Cc: linux-rdma, dri-devel, Christian Koenig, Jason Gunthorpe,
	Doug Ledford, Daniel Vetter

On Mon, Dec 07, 2020 at 02:15:51PM -0800, Jianxin Xiong wrote:
> Dma-buf based memory region requires one extra parameter and is processed
> quite differently. Adding a separate method allows clean separation from
> regular memory regions.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Acked-by: Christian Koenig <christian.koenig@amd.com>
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/infiniband/core/device.c | 1 +
>  include/rdma/ib_verbs.h          | 6 +++++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
>

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 3/4] RDMA/uverbs: Add uverbs command for dma-buf based MR registration
  2020-12-07 22:15   ` Jianxin Xiong
@ 2020-12-08  7:15     ` Leon Romanovsky
  -1 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08  7:15 UTC (permalink / raw)
  To: Jianxin Xiong
  Cc: linux-rdma, dri-devel, Doug Ledford, Jason Gunthorpe,
	Sumit Semwal, Christian Koenig, Daniel Vetter

On Mon, Dec 07, 2020 at 02:15:52PM -0800, Jianxin Xiong wrote:
> Implement a new uverbs ioctl method for memory registration with file
> descriptor as an extra parameter.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Acked-by: Christian Koenig <christian.koenig@amd.com>
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/infiniband/core/uverbs_std_types_mr.c | 117 +++++++++++++++++++++++++-
>  include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 +++
>  2 files changed, 129 insertions(+), 2 deletions(-)
>

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 3/4] RDMA/uverbs: Add uverbs command for dma-buf based MR registration
@ 2020-12-08  7:15     ` Leon Romanovsky
  0 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08  7:15 UTC (permalink / raw)
  To: Jianxin Xiong
  Cc: linux-rdma, dri-devel, Christian Koenig, Jason Gunthorpe,
	Doug Ledford, Daniel Vetter

On Mon, Dec 07, 2020 at 02:15:52PM -0800, Jianxin Xiong wrote:
> Implement a new uverbs ioctl method for memory registration with file
> descriptor as an extra parameter.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Acked-by: Christian Koenig <christian.koenig@amd.com>
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/infiniband/core/uverbs_std_types_mr.c | 117 +++++++++++++++++++++++++-
>  include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 +++
>  2 files changed, 129 insertions(+), 2 deletions(-)
>

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* RE: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-08  7:05     ` Leon Romanovsky
@ 2020-12-08 18:13       ` Xiong, Jianxin
  -1 siblings, 0 replies; 26+ messages in thread
From: Xiong, Jianxin @ 2020-12-08 18:13 UTC (permalink / raw)
  To: Leon Romanovsky
  Cc: linux-rdma, dri-devel, Doug Ledford, Jason Gunthorpe,
	Sumit Semwal, Christian Koenig, Vetter, Daniel

> -----Original Message-----
> From: Leon Romanovsky <leon@kernel.org>
> Sent: Monday, December 07, 2020 11:06 PM
> To: Xiong, Jianxin <jianxin.xiong@intel.com>
> Cc: linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel <daniel.vetter@intel.com>
> Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> 
> On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> > Dma-buf is a standard cross-driver buffer sharing mechanism that can
> > be used to support peer-to-peer access from RDMA devices.
> >
> > Device memory exported via dma-buf is associated with a file descriptor.
> > This is passed to the user space as a property associated with the
> > buffer allocation. When the buffer is registered as a memory region,
> > the file descriptor is passed to the RDMA driver along with other
> > parameters.
> >
> > Implement the common code for importing dma-buf object and mapping
> > dma-buf pages.
> >
> > Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> > Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> > Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > Acked-by: Christian Koenig <christian.koenig@amd.com>
> > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> >
> > Conflicts:
> > 	include/rdma/ib_umem.h
> 
> This probably leftover from rebase, am I right?
> 
> > ---
> >  drivers/infiniband/core/Makefile      |   2 +-
> >  drivers/infiniband/core/umem.c        |   3 +
> >  drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
> >  include/rdma/ib_umem.h                |  43 ++++++++-
> >  4 files changed, 219 insertions(+), 2 deletions(-)  create mode
> > 100644 drivers/infiniband/core/umem_dmabuf.c
> >
> > diff --git a/drivers/infiniband/core/Makefile
> > b/drivers/infiniband/core/Makefile
> > index ccf2670..8ab4eea 100644
> > --- a/drivers/infiniband/core/Makefile
> > +++ b/drivers/infiniband/core/Makefile
> > @@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
> >  				uverbs_std_types_srq.o \
> >  				uverbs_std_types_wq.o \
> >  				uverbs_std_types_qp.o
> > -ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
> > +ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
> >  ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o diff
> > --git a/drivers/infiniband/core/umem.c
> > b/drivers/infiniband/core/umem.c index 7ca4112..cc131f8 100644
> > --- a/drivers/infiniband/core/umem.c
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -2,6 +2,7 @@
> >   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
> >   * Copyright (c) 2005 Cisco Systems.  All rights reserved.
> >   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> >   *
> >   * This software is available to you under a choice of one of two
> >   * licenses.  You may choose to be licensed under the terms of the
> > GNU @@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)  {
> >  	if (!umem)
> >  		return;
> > +	if (umem->is_dmabuf)
> > +		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
> >  	if (umem->is_odp)
> >  		return ib_umem_odp_release(to_ib_umem_odp(umem));
> >
> > diff --git a/drivers/infiniband/core/umem_dmabuf.c
> > b/drivers/infiniband/core/umem_dmabuf.c
> > new file mode 100644
> > index 0000000..e50b955
> > --- /dev/null
> > +++ b/drivers/infiniband/core/umem_dmabuf.c
> > @@ -0,0 +1,173 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> > + */
> > +
> > +#include <linux/dma-buf.h>
> > +#include <linux/dma-resv.h>
> > +#include <linux/dma-mapping.h>
> > +
> > +#include "uverbs.h"
> > +
> > +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct sg_table *sgt;
> > +	struct scatterlist *sg;
> > +	struct dma_fence *fence;
> > +	unsigned long start, end, cur;
> > +	unsigned int nmap;
> > +	int i;
> > +
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (umem_dmabuf->sgt)
> > +		return 0;
> > +
> > +	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
> > +	if (IS_ERR(sgt))
> > +		return PTR_ERR(sgt);
> > +
> > +	/* modify the sg list in-place to match umem address and length */
> > +
> > +	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
> > +	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
> > +		    PAGE_SIZE);
> > +	cur = 0;
> > +	nmap = 0;
> 
> Better to put as part of variable initialization.

Sure, can change that way.

> 
> > +	for_each_sgtable_dma_sg(sgt, sg, i) {
> > +		if (start < cur + sg_dma_len(sg) && cur < end)
> > +			nmap++;
> > +		if (cur <= start && start < cur + sg_dma_len(sg)) {
> > +			unsigned long offset = start - cur;
> > +
> > +			umem_dmabuf->first_sg = sg;
> > +			umem_dmabuf->first_sg_offset = offset;
> > +			sg_dma_address(sg) += offset;
> > +			sg_dma_len(sg) -= offset;
> > +			cur += offset;
> > +		}
> > +		if (cur < end && end <= cur + sg_dma_len(sg)) {
> > +			unsigned long trim = cur + sg_dma_len(sg) - end;
> > +
> > +			umem_dmabuf->last_sg = sg;
> > +			umem_dmabuf->last_sg_trim = trim;
> > +			sg_dma_len(sg) -= trim;
> > +			break;
> > +		}
> > +		cur += sg_dma_len(sg);
> > +	}
> > +
> > +	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
> > +	umem_dmabuf->umem.sg_head.nents = nmap;
> > +	umem_dmabuf->umem.nmap = nmap;
> > +	umem_dmabuf->sgt = sgt;
> > +
> > +	/*
> > +	 * Although the sg list is valid now, the content of the pages
> > +	 * may be not up-to-date. Wait for the exporter to finish
> > +	 * the migration.
> > +	 */
> > +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> > +	if (fence)
> > +		dma_fence_wait(fence, false);
> 
> Any reason do not check return result from dma_fence_wait()?

This is called with interruptible flag set to false and normally should only return 0.
I do see similar usage cases that check the result and don't check the result. Maybe
we can add a WARN_ON here?   

> 
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
> > +
> > +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (!umem_dmabuf->sgt)
> > +		return;
> > +
> > +	/* retore the original sg list */
> > +	if (umem_dmabuf->first_sg) {
> > +		sg_dma_address(umem_dmabuf->first_sg) -=
> > +			umem_dmabuf->first_sg_offset;
> > +		sg_dma_len(umem_dmabuf->first_sg) +=
> > +			umem_dmabuf->first_sg_offset;
> > +		umem_dmabuf->first_sg = NULL;
> > +		umem_dmabuf->first_sg_offset = 0;
> > +	}
> > +	if (umem_dmabuf->last_sg) {
> > +		sg_dma_len(umem_dmabuf->last_sg) +=
> > +			umem_dmabuf->last_sg_trim;
> > +		umem_dmabuf->last_sg = NULL;
> > +		umem_dmabuf->last_sg_trim = 0;
> > +	}
> > +
> > +	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
> > +				 DMA_BIDIRECTIONAL);
> > +
> > +	umem_dmabuf->sgt = NULL;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
> > +
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops) {
> > +	struct dma_buf *dmabuf;
> > +	struct ib_umem_dmabuf *umem_dmabuf;
> > +	struct ib_umem *umem;
> > +	unsigned long end;
> > +	long ret = -EINVAL;
> 
> It is wrong type for the returned value. One of the possible options is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
> ret = ERR_CAST(dmabuf);

At the actual point the value is returned, ERR_PTR(ret) is used. I think we can change the 
variable name to "err" instead to avoid confusion.

> 
> > +
> > +	if (check_add_overflow(offset, (unsigned long)size, &end))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	if (unlikely(!ops || !ops->move_notify))
> 
> Let's not put likely/unlikely in control paths.
> 
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	dmabuf = dma_buf_get(fd);
> > +	if (IS_ERR(dmabuf))
> > +		return (void *)dmabuf;
> 
> return ERR_CAST(dmabuf);

Will fix.

> 
> > +
> > +	if (dmabuf->size < end)
> > +		goto out_release_dmabuf;
> > +
> > +	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
> > +	if (!umem_dmabuf)
> > +		return ERR_PTR(-ENOMEM);
> 
> You are leaking dmabuf here, forgot to call to dma_buf_put();

Will fix.

> 
> > +
> > +	umem = &umem_dmabuf->umem;
> > +	umem->ibdev = device;
> > +	umem->length = size;
> > +	umem->address = offset;
> > +	umem->writable = ib_access_writable(access);
> > +	umem->is_dmabuf = 1;
> > +
> > +	if (unlikely(!ib_umem_num_pages(umem)))
> 
> There is no advantage in "unlikely" here.

Ok.

> 
> > +		goto out_free_umem;
> > +
> > +	umem_dmabuf->attach = dma_buf_dynamic_attach(
> > +					dmabuf,
> > +					device->dma_device,
> > +					ops,
> > +					umem_dmabuf);
> > +	if (IS_ERR(umem_dmabuf->attach)) {
> > +		ret = PTR_ERR(umem_dmabuf->attach);
> > +		goto out_free_umem;
> > +	}
> > +	return umem;
> > +
> > +out_free_umem:
> > +	kfree(umem_dmabuf);
> > +
> > +out_release_dmabuf:
> > +	dma_buf_put(dmabuf);
> > +	return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_get);
> > +
> > +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
> > +
> > +	dma_buf_detach(dmabuf, umem_dmabuf->attach);
> > +	dma_buf_put(dmabuf);
> > +	kfree(umem_dmabuf);
> > +}
> > diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index
> > 7752211..b49a96d 100644
> > --- a/include/rdma/ib_umem.h
> > +++ b/include/rdma/ib_umem.h
> > @@ -1,6 +1,7 @@
> >  /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
> >  /*
> >   * Copyright (c) 2007 Cisco Systems.  All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation.  All rights reserved.
> >   */
> >
> >  #ifndef IB_UMEM_H
> > @@ -13,6 +14,7 @@
> >
> >  struct ib_ucontext;
> >  struct ib_umem_odp;
> > +struct dma_buf_attach_ops;
> >
> >  struct ib_umem {
> >  	struct ib_device       *ibdev;
> > @@ -22,12 +24,29 @@ struct ib_umem {
> >  	unsigned long		address;
> >  	u32 writable : 1;
> >  	u32 is_odp : 1;
> > +	u32 is_dmabuf : 1;
> >  	struct work_struct	work;
> >  	struct sg_table sg_head;
> >  	int             nmap;
> >  	unsigned int    sg_nents;
> >  };
> >
> > +struct ib_umem_dmabuf {
> > +	struct ib_umem umem;
> > +	struct dma_buf_attachment *attach;
> > +	struct sg_table *sgt;
> > +	struct scatterlist *first_sg;
> > +	struct scatterlist *last_sg;
> > +	unsigned long first_sg_offset;
> > +	unsigned long last_sg_trim;
> > +	void *private;
> > +};
> > +
> > +static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem
> > +*umem) {
> > +	return container_of(umem, struct ib_umem_dmabuf, umem); }
> > +
> >  /* Returns the offset of the umem start relative to the first page.
> > */  static inline int ib_umem_offset(struct ib_umem *umem)  { @@ -86,6
> > +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem,
> > size_t offset,  unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
> >  				     unsigned long pgsz_bitmap,
> >  				     unsigned long virt);
> > +
> >  /**
> >   * ib_umem_find_best_pgoff - Find best HW page size
> >   *
> > @@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
> >  				      dma_addr & pgoff_bitmask);
> >  }
> >
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops); int
> > +ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
> > +
> >  #else /* CONFIG_INFINIBAND_USER_MEM */
> >
> >  #include <linux/err.h>
> > @@ -143,7 +171,20 @@ static inline unsigned long
> > ib_umem_find_best_pgoff(struct ib_umem *umem,  {
> >  	return 0;
> >  }
> > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +						 unsigned long offset,
> > +						 size_t size, int fd,
> > +						 int access,
> > +						 struct dma_buf_attach_ops *ops) {
> > +	return ERR_PTR(-EINVAL);
> 
> Probably, It should be EOPNOTSUPP and not EINVAL.

EINVAL is used here to be consistent with existing definitions in the same file.

> 
> > +}
> > +static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) {
> > +	return -EINVAL;
> > +}
> > +static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) { } static inline void ib_umem_dmabuf_release(struct
> > +ib_umem_dmabuf *umem_dmabuf) { }
> >
> >  #endif /* CONFIG_INFINIBAND_USER_MEM */
> > -
> >  #endif /* IB_UMEM_H */
> > --
> > 1.8.3.1
> >

^ permalink raw reply	[flat|nested] 26+ messages in thread
* RE: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-08 18:13       ` Xiong, Jianxin
  0 siblings, 0 replies; 26+ messages in thread
From: Xiong, Jianxin @ 2020-12-08 18:13 UTC (permalink / raw)
  To: Leon Romanovsky
  Cc: linux-rdma, dri-devel, Christian Koenig, Jason Gunthorpe,
	Doug Ledford, Vetter, Daniel

> -----Original Message-----
> From: Leon Romanovsky <leon@kernel.org>
> Sent: Monday, December 07, 2020 11:06 PM
> To: Xiong, Jianxin <jianxin.xiong@intel.com>
> Cc: linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel <daniel.vetter@intel.com>
> Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> 
> On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> > Dma-buf is a standard cross-driver buffer sharing mechanism that can
> > be used to support peer-to-peer access from RDMA devices.
> >
> > Device memory exported via dma-buf is associated with a file descriptor.
> > This is passed to the user space as a property associated with the
> > buffer allocation. When the buffer is registered as a memory region,
> > the file descriptor is passed to the RDMA driver along with other
> > parameters.
> >
> > Implement the common code for importing dma-buf object and mapping
> > dma-buf pages.
> >
> > Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> > Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> > Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > Acked-by: Christian Koenig <christian.koenig@amd.com>
> > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> >
> > Conflicts:
> > 	include/rdma/ib_umem.h
> 
> This probably leftover from rebase, am I right?
> 
> > ---
> >  drivers/infiniband/core/Makefile      |   2 +-
> >  drivers/infiniband/core/umem.c        |   3 +
> >  drivers/infiniband/core/umem_dmabuf.c | 173 ++++++++++++++++++++++++++++++++++
> >  include/rdma/ib_umem.h                |  43 ++++++++-
> >  4 files changed, 219 insertions(+), 2 deletions(-)  create mode
> > 100644 drivers/infiniband/core/umem_dmabuf.c
> >
> > diff --git a/drivers/infiniband/core/Makefile
> > b/drivers/infiniband/core/Makefile
> > index ccf2670..8ab4eea 100644
> > --- a/drivers/infiniband/core/Makefile
> > +++ b/drivers/infiniband/core/Makefile
> > @@ -40,5 +40,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
> >  				uverbs_std_types_srq.o \
> >  				uverbs_std_types_wq.o \
> >  				uverbs_std_types_qp.o
> > -ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
> > +ib_uverbs-$(CONFIG_INFINIBAND_USER_MEM) += umem.o umem_dmabuf.o
> >  ib_uverbs-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o diff
> > --git a/drivers/infiniband/core/umem.c
> > b/drivers/infiniband/core/umem.c index 7ca4112..cc131f8 100644
> > --- a/drivers/infiniband/core/umem.c
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -2,6 +2,7 @@
> >   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
> >   * Copyright (c) 2005 Cisco Systems.  All rights reserved.
> >   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> >   *
> >   * This software is available to you under a choice of one of two
> >   * licenses.  You may choose to be licensed under the terms of the
> > GNU @@ -278,6 +279,8 @@ void ib_umem_release(struct ib_umem *umem)  {
> >  	if (!umem)
> >  		return;
> > +	if (umem->is_dmabuf)
> > +		return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
> >  	if (umem->is_odp)
> >  		return ib_umem_odp_release(to_ib_umem_odp(umem));
> >
> > diff --git a/drivers/infiniband/core/umem_dmabuf.c
> > b/drivers/infiniband/core/umem_dmabuf.c
> > new file mode 100644
> > index 0000000..e50b955
> > --- /dev/null
> > +++ b/drivers/infiniband/core/umem_dmabuf.c
> > @@ -0,0 +1,173 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2020 Intel Corporation. All rights reserved.
> > + */
> > +
> > +#include <linux/dma-buf.h>
> > +#include <linux/dma-resv.h>
> > +#include <linux/dma-mapping.h>
> > +
> > +#include "uverbs.h"
> > +
> > +int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct sg_table *sgt;
> > +	struct scatterlist *sg;
> > +	struct dma_fence *fence;
> > +	unsigned long start, end, cur;
> > +	unsigned int nmap;
> > +	int i;
> > +
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (umem_dmabuf->sgt)
> > +		return 0;
> > +
> > +	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
> > +	if (IS_ERR(sgt))
> > +		return PTR_ERR(sgt);
> > +
> > +	/* modify the sg list in-place to match umem address and length */
> > +
> > +	start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE);
> > +	end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length,
> > +		    PAGE_SIZE);
> > +	cur = 0;
> > +	nmap = 0;
> 
> Better to put as part of variable initialization.

Sure, can change that way.

> 
> > +	for_each_sgtable_dma_sg(sgt, sg, i) {
> > +		if (start < cur + sg_dma_len(sg) && cur < end)
> > +			nmap++;
> > +		if (cur <= start && start < cur + sg_dma_len(sg)) {
> > +			unsigned long offset = start - cur;
> > +
> > +			umem_dmabuf->first_sg = sg;
> > +			umem_dmabuf->first_sg_offset = offset;
> > +			sg_dma_address(sg) += offset;
> > +			sg_dma_len(sg) -= offset;
> > +			cur += offset;
> > +		}
> > +		if (cur < end && end <= cur + sg_dma_len(sg)) {
> > +			unsigned long trim = cur + sg_dma_len(sg) - end;
> > +
> > +			umem_dmabuf->last_sg = sg;
> > +			umem_dmabuf->last_sg_trim = trim;
> > +			sg_dma_len(sg) -= trim;
> > +			break;
> > +		}
> > +		cur += sg_dma_len(sg);
> > +	}
> > +
> > +	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
> > +	umem_dmabuf->umem.sg_head.nents = nmap;
> > +	umem_dmabuf->umem.nmap = nmap;
> > +	umem_dmabuf->sgt = sgt;
> > +
> > +	/*
> > +	 * Although the sg list is valid now, the content of the pages
> > +	 * may be not up-to-date. Wait for the exporter to finish
> > +	 * the migration.
> > +	 */
> > +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> > +	if (fence)
> > +		dma_fence_wait(fence, false);
> 
> Any reason do not check return result from dma_fence_wait()?

This is called with interruptible flag set to false and normally should only return 0.
I do see similar usage cases that check the result and don't check the result. Maybe
we can add a WARN_ON here?   

> 
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
> > +
> > +void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> > +
> > +	if (!umem_dmabuf->sgt)
> > +		return;
> > +
> > +	/* retore the original sg list */
> > +	if (umem_dmabuf->first_sg) {
> > +		sg_dma_address(umem_dmabuf->first_sg) -=
> > +			umem_dmabuf->first_sg_offset;
> > +		sg_dma_len(umem_dmabuf->first_sg) +=
> > +			umem_dmabuf->first_sg_offset;
> > +		umem_dmabuf->first_sg = NULL;
> > +		umem_dmabuf->first_sg_offset = 0;
> > +	}
> > +	if (umem_dmabuf->last_sg) {
> > +		sg_dma_len(umem_dmabuf->last_sg) +=
> > +			umem_dmabuf->last_sg_trim;
> > +		umem_dmabuf->last_sg = NULL;
> > +		umem_dmabuf->last_sg_trim = 0;
> > +	}
> > +
> > +	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
> > +				 DMA_BIDIRECTIONAL);
> > +
> > +	umem_dmabuf->sgt = NULL;
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages);
> > +
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops) {
> > +	struct dma_buf *dmabuf;
> > +	struct ib_umem_dmabuf *umem_dmabuf;
> > +	struct ib_umem *umem;
> > +	unsigned long end;
> > +	long ret = -EINVAL;
> 
> It is wrong type for the returned value. One of the possible options is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
> ret = ERR_CAST(dmabuf);

At the actual point the value is returned, ERR_PTR(ret) is used. I think we can change the 
variable name to "err" instead to avoid confusion.

> 
> > +
> > +	if (check_add_overflow(offset, (unsigned long)size, &end))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	if (unlikely(!ops || !ops->move_notify))
> 
> Let's not put likely/unlikely in control paths.
> 
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	dmabuf = dma_buf_get(fd);
> > +	if (IS_ERR(dmabuf))
> > +		return (void *)dmabuf;
> 
> return ERR_CAST(dmabuf);

Will fix.

> 
> > +
> > +	if (dmabuf->size < end)
> > +		goto out_release_dmabuf;
> > +
> > +	umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL);
> > +	if (!umem_dmabuf)
> > +		return ERR_PTR(-ENOMEM);
> 
> You are leaking dmabuf here, forgot to call to dma_buf_put();

Will fix.

> 
> > +
> > +	umem = &umem_dmabuf->umem;
> > +	umem->ibdev = device;
> > +	umem->length = size;
> > +	umem->address = offset;
> > +	umem->writable = ib_access_writable(access);
> > +	umem->is_dmabuf = 1;
> > +
> > +	if (unlikely(!ib_umem_num_pages(umem)))
> 
> There is no advantage in "unlikely" here.

Ok.

> 
> > +		goto out_free_umem;
> > +
> > +	umem_dmabuf->attach = dma_buf_dynamic_attach(
> > +					dmabuf,
> > +					device->dma_device,
> > +					ops,
> > +					umem_dmabuf);
> > +	if (IS_ERR(umem_dmabuf->attach)) {
> > +		ret = PTR_ERR(umem_dmabuf->attach);
> > +		goto out_free_umem;
> > +	}
> > +	return umem;
> > +
> > +out_free_umem:
> > +	kfree(umem_dmabuf);
> > +
> > +out_release_dmabuf:
> > +	dma_buf_put(dmabuf);
> > +	return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL(ib_umem_dmabuf_get);
> > +
> > +void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) {
> > +	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;
> > +
> > +	dma_buf_detach(dmabuf, umem_dmabuf->attach);
> > +	dma_buf_put(dmabuf);
> > +	kfree(umem_dmabuf);
> > +}
> > diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index
> > 7752211..b49a96d 100644
> > --- a/include/rdma/ib_umem.h
> > +++ b/include/rdma/ib_umem.h
> > @@ -1,6 +1,7 @@
> >  /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
> >  /*
> >   * Copyright (c) 2007 Cisco Systems.  All rights reserved.
> > + * Copyright (c) 2020 Intel Corporation.  All rights reserved.
> >   */
> >
> >  #ifndef IB_UMEM_H
> > @@ -13,6 +14,7 @@
> >
> >  struct ib_ucontext;
> >  struct ib_umem_odp;
> > +struct dma_buf_attach_ops;
> >
> >  struct ib_umem {
> >  	struct ib_device       *ibdev;
> > @@ -22,12 +24,29 @@ struct ib_umem {
> >  	unsigned long		address;
> >  	u32 writable : 1;
> >  	u32 is_odp : 1;
> > +	u32 is_dmabuf : 1;
> >  	struct work_struct	work;
> >  	struct sg_table sg_head;
> >  	int             nmap;
> >  	unsigned int    sg_nents;
> >  };
> >
> > +struct ib_umem_dmabuf {
> > +	struct ib_umem umem;
> > +	struct dma_buf_attachment *attach;
> > +	struct sg_table *sgt;
> > +	struct scatterlist *first_sg;
> > +	struct scatterlist *last_sg;
> > +	unsigned long first_sg_offset;
> > +	unsigned long last_sg_trim;
> > +	void *private;
> > +};
> > +
> > +static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem
> > +*umem) {
> > +	return container_of(umem, struct ib_umem_dmabuf, umem); }
> > +
> >  /* Returns the offset of the umem start relative to the first page.
> > */  static inline int ib_umem_offset(struct ib_umem *umem)  { @@ -86,6
> > +105,7 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem,
> > size_t offset,  unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
> >  				     unsigned long pgsz_bitmap,
> >  				     unsigned long virt);
> > +
> >  /**
> >   * ib_umem_find_best_pgoff - Find best HW page size
> >   *
> > @@ -116,6 +136,14 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
> >  				      dma_addr & pgoff_bitmask);
> >  }
> >
> > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +				   unsigned long offset, size_t size,
> > +				   int fd, int access,
> > +				   const struct dma_buf_attach_ops *ops); int
> > +ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf); void
> > +ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
> > +
> >  #else /* CONFIG_INFINIBAND_USER_MEM */
> >
> >  #include <linux/err.h>
> > @@ -143,7 +171,20 @@ static inline unsigned long
> > ib_umem_find_best_pgoff(struct ib_umem *umem,  {
> >  	return 0;
> >  }
> > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > +						 unsigned long offset,
> > +						 size_t size, int fd,
> > +						 int access,
> > +						 struct dma_buf_attach_ops *ops) {
> > +	return ERR_PTR(-EINVAL);
> 
> Probably, It should be EOPNOTSUPP and not EINVAL.

EINVAL is used here to be consistent with existing definitions in the same file.

> 
> > +}
> > +static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) {
> > +	return -EINVAL;
> > +}
> > +static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf
> > +*umem_dmabuf) { } static inline void ib_umem_dmabuf_release(struct
> > +ib_umem_dmabuf *umem_dmabuf) { }
> >
> >  #endif /* CONFIG_INFINIBAND_USER_MEM */
> > -
> >  #endif /* IB_UMEM_H */
> > --
> > 1.8.3.1
> >
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^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-08 18:13       ` Xiong, Jianxin
@ 2020-12-08 18:59         ` Jason Gunthorpe
  -1 siblings, 0 replies; 26+ messages in thread
From: Jason Gunthorpe @ 2020-12-08 18:59 UTC (permalink / raw)
  To: Xiong, Jianxin
  Cc: Leon Romanovsky, linux-rdma, dri-devel, Doug Ledford,
	Sumit Semwal, Christian Koenig, Vetter, Daniel

On Tue, Dec 08, 2020 at 06:13:20PM +0000, Xiong, Jianxin wrote:

> > > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > +						 unsigned long offset,
> > > +						 size_t size, int fd,
> > > +						 int access,
> > > +						 struct dma_buf_attach_ops *ops) {
> > > +	return ERR_PTR(-EINVAL);
> > 
> > Probably, It should be EOPNOTSUPP and not EINVAL.
> 
> EINVAL is used here to be consistent with existing definitions in the same file.

They may be wrong, EOPNOTSUPP is right for this situation

Jason

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-08 18:59         ` Jason Gunthorpe
  0 siblings, 0 replies; 26+ messages in thread
From: Jason Gunthorpe @ 2020-12-08 18:59 UTC (permalink / raw)
  To: Xiong, Jianxin
  Cc: Leon Romanovsky, linux-rdma, dri-devel, Doug Ledford, Vetter,
	Daniel, Christian Koenig

On Tue, Dec 08, 2020 at 06:13:20PM +0000, Xiong, Jianxin wrote:

> > > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > +						 unsigned long offset,
> > > +						 size_t size, int fd,
> > > +						 int access,
> > > +						 struct dma_buf_attach_ops *ops) {
> > > +	return ERR_PTR(-EINVAL);
> > 
> > Probably, It should be EOPNOTSUPP and not EINVAL.
> 
> EINVAL is used here to be consistent with existing definitions in the same file.

They may be wrong, EOPNOTSUPP is right for this situation

Jason
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^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-08 18:13       ` Xiong, Jianxin
@ 2020-12-08 19:02         ` Leon Romanovsky
  -1 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08 19:02 UTC (permalink / raw)
  To: Xiong, Jianxin
  Cc: linux-rdma, dri-devel, Doug Ledford, Jason Gunthorpe,
	Sumit Semwal, Christian Koenig, Vetter, Daniel

On Tue, Dec 08, 2020 at 06:13:20PM +0000, Xiong, Jianxin wrote:
> > -----Original Message-----
> > From: Leon Romanovsky <leon@kernel.org>
> > Sent: Monday, December 07, 2020 11:06 PM
> > To: Xiong, Jianxin <jianxin.xiong@intel.com>
> > Cc: linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> > Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel <daniel.vetter@intel.com>
> > Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> >
> > On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> > > Dma-buf is a standard cross-driver buffer sharing mechanism that can
> > > be used to support peer-to-peer access from RDMA devices.
> > >
> > > Device memory exported via dma-buf is associated with a file descriptor.
> > > This is passed to the user space as a property associated with the
> > > buffer allocation. When the buffer is registered as a memory region,
> > > the file descriptor is passed to the RDMA driver along with other
> > > parameters.
> > >
> > > Implement the common code for importing dma-buf object and mapping
> > > dma-buf pages.
> > >
> > > Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> > > Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> > > Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > > Acked-by: Christian Koenig <christian.koenig@amd.com>
> > > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > >
> > > Conflicts:
> > > 	include/rdma/ib_umem.h
> >

<...>

> > > +	/*
> > > +	 * Although the sg list is valid now, the content of the pages
> > > +	 * may be not up-to-date. Wait for the exporter to finish
> > > +	 * the migration.
> > > +	 */
> > > +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> > > +	if (fence)
> > > +		dma_fence_wait(fence, false);
> >
> > Any reason do not check return result from dma_fence_wait()?
>
> This is called with interruptible flag set to false and normally should only return 0.
> I do see similar usage cases that check the result and don't check the result. Maybe
> we can add a WARN_ON here?

I have no idea :), just saw that other places check returned value.

<...>

> > > +
> > > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > +				   unsigned long offset, size_t size,
> > > +				   int fd, int access,
> > > +				   const struct dma_buf_attach_ops *ops) {
> > > +	struct dma_buf *dmabuf;
> > > +	struct ib_umem_dmabuf *umem_dmabuf;
> > > +	struct ib_umem *umem;
> > > +	unsigned long end;
> > > +	long ret = -EINVAL;
> >
> > It is wrong type for the returned value. One of the possible options is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
> > ret = ERR_CAST(dmabuf);
>
> At the actual point the value is returned, ERR_PTR(ret) is used. I think we can change the
> variable name to "err" instead to avoid confusion.

The point is that "ret" should be declared as "struct ib_umem *" and not
as "long" and ERR_CAST() should be used instead of (void *).

<...>

> > > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > +						 unsigned long offset,
> > > +						 size_t size, int fd,
> > > +						 int access,
> > > +						 struct dma_buf_attach_ops *ops) {
> > > +	return ERR_PTR(-EINVAL);
> >
> > Probably, It should be EOPNOTSUPP and not EINVAL.
>
> EINVAL is used here to be consistent with existing definitions in the same file.

ok

Thanks

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-08 19:02         ` Leon Romanovsky
  0 siblings, 0 replies; 26+ messages in thread
From: Leon Romanovsky @ 2020-12-08 19:02 UTC (permalink / raw)
  To: Xiong, Jianxin
  Cc: linux-rdma, dri-devel, Christian Koenig, Jason Gunthorpe,
	Doug Ledford, Vetter, Daniel

On Tue, Dec 08, 2020 at 06:13:20PM +0000, Xiong, Jianxin wrote:
> > -----Original Message-----
> > From: Leon Romanovsky <leon@kernel.org>
> > Sent: Monday, December 07, 2020 11:06 PM
> > To: Xiong, Jianxin <jianxin.xiong@intel.com>
> > Cc: linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>;
> > Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel <daniel.vetter@intel.com>
> > Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> >
> > On Mon, Dec 07, 2020 at 02:15:50PM -0800, Jianxin Xiong wrote:
> > > Dma-buf is a standard cross-driver buffer sharing mechanism that can
> > > be used to support peer-to-peer access from RDMA devices.
> > >
> > > Device memory exported via dma-buf is associated with a file descriptor.
> > > This is passed to the user space as a property associated with the
> > > buffer allocation. When the buffer is registered as a memory region,
> > > the file descriptor is passed to the RDMA driver along with other
> > > parameters.
> > >
> > > Implement the common code for importing dma-buf object and mapping
> > > dma-buf pages.
> > >
> > > Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> > > Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> > > Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > > Acked-by: Christian Koenig <christian.koenig@amd.com>
> > > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > >
> > > Conflicts:
> > > 	include/rdma/ib_umem.h
> >

<...>

> > > +	/*
> > > +	 * Although the sg list is valid now, the content of the pages
> > > +	 * may be not up-to-date. Wait for the exporter to finish
> > > +	 * the migration.
> > > +	 */
> > > +	fence = dma_resv_get_excl(umem_dmabuf->attach->dmabuf->resv);
> > > +	if (fence)
> > > +		dma_fence_wait(fence, false);
> >
> > Any reason do not check return result from dma_fence_wait()?
>
> This is called with interruptible flag set to false and normally should only return 0.
> I do see similar usage cases that check the result and don't check the result. Maybe
> we can add a WARN_ON here?

I have no idea :), just saw that other places check returned value.

<...>

> > > +
> > > +struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > +				   unsigned long offset, size_t size,
> > > +				   int fd, int access,
> > > +				   const struct dma_buf_attach_ops *ops) {
> > > +	struct dma_buf *dmabuf;
> > > +	struct ib_umem_dmabuf *umem_dmabuf;
> > > +	struct ib_umem *umem;
> > > +	unsigned long end;
> > > +	long ret = -EINVAL;
> >
> > It is wrong type for the returned value. One of the possible options is to declare "struct ib_umem *ret;" and set ret = ERR_PTR(-EINVAL) or
> > ret = ERR_CAST(dmabuf);
>
> At the actual point the value is returned, ERR_PTR(ret) is used. I think we can change the
> variable name to "err" instead to avoid confusion.

The point is that "ret" should be declared as "struct ib_umem *" and not
as "long" and ERR_CAST() should be used instead of (void *).

<...>

> > > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > +						 unsigned long offset,
> > > +						 size_t size, int fd,
> > > +						 int access,
> > > +						 struct dma_buf_attach_ops *ops) {
> > > +	return ERR_PTR(-EINVAL);
> >
> > Probably, It should be EOPNOTSUPP and not EINVAL.
>
> EINVAL is used here to be consistent with existing definitions in the same file.

ok

Thanks
_______________________________________________
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dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* RE: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
  2020-12-08 18:59         ` Jason Gunthorpe
@ 2020-12-08 19:33           ` Xiong, Jianxin
  -1 siblings, 0 replies; 26+ messages in thread
From: Xiong, Jianxin @ 2020-12-08 19:33 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: Leon Romanovsky, linux-rdma, dri-devel, Doug Ledford,
	Sumit Semwal, Christian Koenig, Vetter, Daniel

> -----Original Message-----
> From: Jason Gunthorpe <jgg@ziepe.ca>
> Sent: Tuesday, December 08, 2020 10:59 AM
> To: Xiong, Jianxin <jianxin.xiong@intel.com>
> Cc: Leon Romanovsky <leon@kernel.org>; linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford
> <dledford@redhat.com>; Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel
> <daniel.vetter@intel.com>
> Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> 
> On Tue, Dec 08, 2020 at 06:13:20PM +0000, Xiong, Jianxin wrote:
> 
> > > > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > > +						 unsigned long offset,
> > > > +						 size_t size, int fd,
> > > > +						 int access,
> > > > +						 struct dma_buf_attach_ops *ops) {
> > > > +	return ERR_PTR(-EINVAL);
> > >
> > > Probably, It should be EOPNOTSUPP and not EINVAL.
> >
> > EINVAL is used here to be consistent with existing definitions in the same file.
> 
> They may be wrong, EOPNOTSUPP is right for this situation

Ok, let me change all of them to EOPNOTSUPP.


^ permalink raw reply	[flat|nested] 26+ messages in thread
* RE: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
@ 2020-12-08 19:33           ` Xiong, Jianxin
  0 siblings, 0 replies; 26+ messages in thread
From: Xiong, Jianxin @ 2020-12-08 19:33 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: Leon Romanovsky, linux-rdma, dri-devel, Doug Ledford, Vetter,
	Daniel, Christian Koenig

> -----Original Message-----
> From: Jason Gunthorpe <jgg@ziepe.ca>
> Sent: Tuesday, December 08, 2020 10:59 AM
> To: Xiong, Jianxin <jianxin.xiong@intel.com>
> Cc: Leon Romanovsky <leon@kernel.org>; linux-rdma@vger.kernel.org; dri-devel@lists.freedesktop.org; Doug Ledford
> <dledford@redhat.com>; Sumit Semwal <sumit.semwal@linaro.org>; Christian Koenig <christian.koenig@amd.com>; Vetter, Daniel
> <daniel.vetter@intel.com>
> Subject: Re: [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region
> 
> On Tue, Dec 08, 2020 at 06:13:20PM +0000, Xiong, Jianxin wrote:
> 
> > > > +static inline struct ib_umem *ib_umem_dmabuf_get(struct ib_device *device,
> > > > +						 unsigned long offset,
> > > > +						 size_t size, int fd,
> > > > +						 int access,
> > > > +						 struct dma_buf_attach_ops *ops) {
> > > > +	return ERR_PTR(-EINVAL);
> > >
> > > Probably, It should be EOPNOTSUPP and not EINVAL.
> >
> > EINVAL is used here to be consistent with existing definitions in the same file.
> 
> They may be wrong, EOPNOTSUPP is right for this situation

Ok, let me change all of them to EOPNOTSUPP.

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^ permalink raw reply	[flat|nested] 26+ messages in thread
end of thread, other threads:[~2020-12-09  8:32 UTC | newest]

Thread overview: 26+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-07 22:15 [PATCH v13 0/4] RDMA: Add dma-buf support Jianxin Xiong
2020-12-07 22:15 ` Jianxin Xiong
2020-12-07 22:15 ` [PATCH v13 1/4] RDMA/umem: Support importing dma-buf as user memory region Jianxin Xiong
2020-12-07 22:15   ` Jianxin Xiong
2020-12-08  7:05   ` Leon Romanovsky
2020-12-08  7:05     ` Leon Romanovsky
2020-12-08  7:10     ` Xiong, Jianxin
2020-12-08  7:10       ` Xiong, Jianxin
2020-12-08 18:13     ` Xiong, Jianxin
2020-12-08 18:13       ` Xiong, Jianxin
2020-12-08 18:59       ` Jason Gunthorpe
2020-12-08 18:59         ` Jason Gunthorpe
2020-12-08 19:33         ` Xiong, Jianxin
2020-12-08 19:33           ` Xiong, Jianxin
2020-12-08 19:02       ` Leon Romanovsky
2020-12-08 19:02         ` Leon Romanovsky
2020-12-07 22:15 ` [PATCH v13 2/4] RDMA/core: Add device method for registering dma-buf based " Jianxin Xiong
2020-12-07 22:15   ` Jianxin Xiong
2020-12-08  7:12   ` Leon Romanovsky
2020-12-08  7:12     ` Leon Romanovsky
2020-12-07 22:15 ` [PATCH v13 3/4] RDMA/uverbs: Add uverbs command for dma-buf based MR registration Jianxin Xiong
2020-12-07 22:15   ` Jianxin Xiong
2020-12-08  7:15   ` Leon Romanovsky
2020-12-08  7:15     ` Leon Romanovsky
2020-12-07 22:15 ` [PATCH v13 4/4] RDMA/mlx5: Support dma-buf based userspace memory region Jianxin Xiong
2020-12-07 22:15   ` Jianxin Xiong

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