[PATCH rdma-core v3 4/6] pyverbs: Add dma-buf based MR support
Daniel Vetter
daniel at ffwll.ch
Mon Nov 30 14:57:41 UTC 2020
On Fri, Nov 27, 2020 at 12:55:41PM -0800, Jianxin Xiong wrote:
> Define a new sub-class of 'MR' that uses dma-buf object for the memory
> region. Define a new class 'DmaBuf' as a wrapper for dma-buf allocation
> mechanism implemented in C.
>
> Add a method to buildlib for building modules with mixed Cython and C
> source.
>
> Signed-off-by: Jianxin Xiong <jianxin.xiong at intel.com>
> ---
> buildlib/pyverbs_functions.cmake | 52 +++++++
> pyverbs/CMakeLists.txt | 7 +
> pyverbs/dmabuf.pxd | 15 ++
> pyverbs/dmabuf.pyx | 72 ++++++++++
> pyverbs/dmabuf_alloc.c | 296 +++++++++++++++++++++++++++++++++++++++
> pyverbs/dmabuf_alloc.h | 19 +++
> pyverbs/libibverbs.pxd | 2 +
> pyverbs/mr.pxd | 6 +
> pyverbs/mr.pyx | 103 +++++++++++++-
> 9 files changed, 570 insertions(+), 2 deletions(-)
> create mode 100644 pyverbs/dmabuf.pxd
> create mode 100644 pyverbs/dmabuf.pyx
> create mode 100644 pyverbs/dmabuf_alloc.c
> create mode 100644 pyverbs/dmabuf_alloc.h
>
> diff --git a/buildlib/pyverbs_functions.cmake b/buildlib/pyverbs_functions.cmake
> index 953cec2..2f6788e 100644
> --- a/buildlib/pyverbs_functions.cmake
> +++ b/buildlib/pyverbs_functions.cmake
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB)
> # Copyright (c) 2018, Mellanox Technologies. All rights reserved. See COPYING file
> +# Copyright (c) 2020, Intel Corporation. All rights reserved. See COPYING file
>
> function(rdma_cython_module PY_MODULE LINKER_FLAGS)
> foreach(PYX_FILE ${ARGN})
> @@ -32,6 +33,57 @@ function(rdma_cython_module PY_MODULE LINKER_FLAGS)
> endforeach()
> endfunction()
>
> +function(rdma_multifile_module PY_MODULE MODULE_NAME LINKER_FLAGS)
> + set(ALL_CFILES "")
> + foreach(SRC_FILE ${ARGN})
> + get_filename_component(FILENAME ${SRC_FILE} NAME_WE)
> + get_filename_component(DIR ${SRC_FILE} DIRECTORY)
> + get_filename_component(EXT ${SRC_FILE} EXT)
> + if (DIR)
> + set(SRC_PATH "${CMAKE_CURRENT_SOURCE_DIR}/${DIR}")
> + else()
> + set(SRC_PATH "${CMAKE_CURRENT_SOURCE_DIR}")
> + endif()
> + if (${EXT} STREQUAL ".pyx")
> + set(PYX "${SRC_PATH}/${FILENAME}.pyx")
> + set(CFILE "${CMAKE_CURRENT_BINARY_DIR}/${FILENAME}.c")
> + include_directories(${PYTHON_INCLUDE_DIRS})
> + add_custom_command(
> + OUTPUT "${CFILE}"
> + MAIN_DEPENDENCY "${PYX}"
> + COMMAND ${CYTHON_EXECUTABLE} "${PYX}" -o "${CFILE}"
> + "-I${PYTHON_INCLUDE_DIRS}"
> + COMMENT "Cythonizing ${PYX}"
> + )
> + set(ALL_CFILES "${ALL_CFILES};${CFILE}")
> + elseif(${EXT} STREQUAL ".c")
> + set(CFILE_ORIG "${SRC_PATH}/${FILENAME}.c")
> + set(CFILE "${CMAKE_CURRENT_BINARY_DIR}/${FILENAME}.c")
> + if (NOT ${CFILE_ORIG} STREQUAL ${CFILE})
> + rdma_create_symlink("${CFILE_ORIG}" "${CFILE}")
> + endif()
> + set(ALL_CFILES "${ALL_CFILES};${CFILE}")
> + elseif(${EXT} STREQUAL ".h")
> + set(HFILE_ORIG "${SRC_PATH}/${FILENAME}.h")
> + set(HFILE "${CMAKE_CURRENT_BINARY_DIR}/${FILENAME}.h")
> + if (NOT ${HFILE_ORIG} STREQUAL ${HFILE})
> + rdma_create_symlink("${HFILE_ORIG}" "${HFILE}")
> + endif()
> + else()
> + continue()
> + endif()
> + endforeach()
> + string(REGEX REPLACE "\\.so$" "" SONAME "${MODULE_NAME}${CMAKE_PYTHON_SO_SUFFIX}")
> + add_library(${SONAME} SHARED ${ALL_CFILES})
> + set_target_properties(${SONAME} PROPERTIES
> + COMPILE_FLAGS "${CMAKE_C_FLAGS} -fPIC -fno-strict-aliasing -Wno-unused-function -Wno-redundant-decls -Wno-shadow -Wno-cast-function-type -Wno-implicit-fallthrough -Wno-unknown-warning -Wno-unknown-warning-option -Wno-deprecated-declarations ${NO_VAR_TRACKING_FLAGS}"
> + LIBRARY_OUTPUT_DIRECTORY "${BUILD_PYTHON}/${PY_MODULE}"
> + PREFIX "")
> + target_link_libraries(${SONAME} LINK_PRIVATE ${PYTHON_LIBRARIES} ibverbs rdmacm ${LINKER_FLAGS})
> + install(TARGETS ${SONAME}
> + DESTINATION ${CMAKE_INSTALL_PYTHON_ARCH_LIB}/${PY_MODULE})
> +endfunction()
> +
> function(rdma_python_module PY_MODULE)
> foreach(PY_FILE ${ARGN})
> get_filename_component(LINK "${CMAKE_CURRENT_SOURCE_DIR}/${PY_FILE}" ABSOLUTE)
> diff --git a/pyverbs/CMakeLists.txt b/pyverbs/CMakeLists.txt
> index 9542c4b..1b21e7b 100644
> --- a/pyverbs/CMakeLists.txt
> +++ b/pyverbs/CMakeLists.txt
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB)
> # Copyright (c) 2019, Mellanox Technologies. All rights reserved. See COPYING file
> +# Copyright (c) 2020, Intel Corporation. All rights reserved. See COPYING file
>
> rdma_cython_module(pyverbs ""
> addr.pyx
> @@ -24,6 +25,12 @@ rdma_python_module(pyverbs
> utils.py
> )
>
> +rdma_multifile_module(pyverbs dmabuf ""
> + dmabuf.pyx
> + dmabuf_alloc.c
> + dmabuf_alloc.h
> + )
> +
> # mlx5 and efa providers are not built without coherent DMA, e.g. ARM32 build.
> if (HAVE_COHERENT_DMA)
> add_subdirectory(providers/mlx5)
> diff --git a/pyverbs/dmabuf.pxd b/pyverbs/dmabuf.pxd
> new file mode 100644
> index 0000000..3ef5dfb
> --- /dev/null
> +++ b/pyverbs/dmabuf.pxd
> @@ -0,0 +1,15 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB)
> +# Copyright (c) 2020, Intel Corporation. All rights reserved. See COPYING file
> +
> +#cython: language_level=3
> +
> +cdef class DmaBuf:
> + cdef int dri_fd
> + cdef int handle
> + cdef int fd
> + cdef unsigned long size
> + cdef unsigned long map_offset
> + cdef void *dmabuf
> + cdef object dmabuf_mrs
> + cdef add_ref(self, obj)
> + cpdef close(self)
> diff --git a/pyverbs/dmabuf.pyx b/pyverbs/dmabuf.pyx
> new file mode 100644
> index 0000000..23d8e2a
> --- /dev/null
> +++ b/pyverbs/dmabuf.pyx
> @@ -0,0 +1,72 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB)
> +# Copyright (c) 2020, Intel Corporation. All rights reserved. See COPYING file
> +
> +#cython: language_level=3
> +
> +import weakref
> +
> +from pyverbs.base cimport close_weakrefs
> +from pyverbs.base import PyverbsRDMAErrno
> +from pyverbs.mr cimport DmaBufMR
> +
> +cdef extern from "dmabuf_alloc.h":
> + cdef struct dmabuf:
> + pass
> + dmabuf *dmabuf_alloc(int unit, unsigned long size)
> + void dmabuf_free(dmabuf *dmabuf)
> + int dmabuf_get_dri_fd(dmabuf *dmabuf)
> + int dmabuf_get_fd(dmabuf *dmabuf)
> + unsigned long dmabuf_get_offset(dmabuf *dmabuf)
> +
> +
> +cdef class DmaBuf:
> + def __init__(self, size, unit=0):
> + """
> + Allocate DmaBuf object from a GPU device. This is done through the
> + DRI device interface. Usually this requires the effective user id
> + being a member of the 'render' group.
> + :param size: The size (in number of bytes) of the buffer.
> + :param unit: The unit number of the GPU to allocate the buffer from.
> + :return: The newly created DmaBuf object on success.
> + """
> + self.dmabuf_mrs = weakref.WeakSet()
> + self.dmabuf = dmabuf_alloc(size, unit)
> + if self.dmabuf == NULL:
> + raise PyverbsRDMAErrno(f'Failed to allocate dmabuf of size {size} on unit {unit}')
> + self.dri_fd = dmabuf_get_dri_fd(<dmabuf *>self.dmabuf)
dri_fd seems unused by the tests
> + self.fd = dmabuf_get_fd(<dmabuf *>self.dmabuf)
> + self.map_offset = dmabuf_get_offset(<dmabuf *>self.dmabuf)
> +
> + def __dealloc__(self):
> + self.close()
> +
> + cpdef close(self):
> + if self.dmabuf == NULL:
> + return None
> + close_weakrefs([self.dmabuf_mrs])
> + dmabuf_free(<dmabuf *>self.dmabuf)
> + self.dmabuf = NULL
> +
> + cdef add_ref(self, obj):
> + if isinstance(obj, DmaBufMR):
> + self.dmabuf_mrs.add(obj)
> +
> + @property
> + def dri_fd(self):
> + return self.dri_fd
> +
> + @property
> + def handle(self):
> + return self.handle
> +
> + @property
> + def fd(self):
> + return self.fd
> +
> + @property
> + def size(self):
> + return self.size
> +
> + @property
> + def map_offset(self):
> + return self.map_offset
> diff --git a/pyverbs/dmabuf_alloc.c b/pyverbs/dmabuf_alloc.c
> new file mode 100644
> index 0000000..b958a3e
> --- /dev/null
> +++ b/pyverbs/dmabuf_alloc.c
> @@ -0,0 +1,296 @@
> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
> +/*
> + * Copyright 2020 Intel Corporation. All rights reserved. See COPYING file
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <stdint.h>
> +#include <unistd.h>
> +#include <string.h>
> +#include <errno.h>
> +#include <drm/drm.h>
> +#include <drm/i915_drm.h>
> +#include <drm/amdgpu_drm.h>
> +#include <drm/radeon_drm.h>
> +#include <fcntl.h>
> +#include <sys/ioctl.h>
> +#include "dmabuf_alloc.h"
> +
> +/*
> + * Abstraction of the buffer allocation mechanism using the DRI interface.
> + * The interface is accessed by ioctl() calls over the '/dev/dri/renderD*'
> + * device. Successful access usually requires the effective user id being
> + * in the 'render' group.
> + */
> +
> +struct dri {
> + int fd;
> + int (*alloc)(struct dri *dri, uint64_t size, uint32_t *handle);
> + int (*mmap_offset)(struct dri *dri, uint32_t handle, uint64_t *offset);
> +};
> +
> +static int i915_alloc(struct dri *dri, uint64_t size, uint32_t *handle)
> +{
> + struct drm_i915_gem_create gem_create = {0};
> + int err;
> +
> + gem_create.size = size;
> + err = ioctl(dri->fd, DRM_IOCTL_I915_GEM_CREATE, &gem_create);
> + if (err)
> + return err;
> +
> + *handle = gem_create.handle;
> + return 0;
> +}
> +
> +static int amdgpu_alloc(struct dri *dri, size_t size, uint32_t *handle)
> +{
> + union drm_amdgpu_gem_create gem_create = {{0}};
> + int err;
> +
> + gem_create.in.bo_size = size;
> + gem_create.in.domains = AMDGPU_GEM_DOMAIN_VRAM;
I think you minimally also need domain_flags =
AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED, otherwise you can end up being
unlucky and the mmap fails.
I think it would also be good to have a separate mode where the buffer is
forced to be in system memory (AMDGPU_GEM_DOMAIN_GTT and additionally
AMDGPU_GEM_CREATE_CPU_GTT_USWC needed). This should be useful for cases
where p2p doesn't work, but we still want to check the dma-buf
functionality.
> + err = ioctl(dri->fd, DRM_IOCTL_AMDGPU_GEM_CREATE, &gem_create);
> + if (err)
> + return err;
> +
> + *handle = gem_create.out.handle;
> + return 0;
> +}
> +
> +static int radeon_alloc(struct dri *dri, size_t size, uint32_t *handle)
Tbh radeon chips are old enough I wouldn't care. Also doesn't support p2p
dma-buf, so always going to be in system memory when you share. Plus you
also need some more flags like I suggested above I think.
> +{
> + struct drm_radeon_gem_create gem_create = {0};
> + int err;
> +
> + gem_create.size = size;
> + gem_create.initial_domain = RADEON_GEM_DOMAIN_VRAM;
> + err = ioctl(dri->fd, DRM_IOCTL_RADEON_GEM_CREATE, &gem_create);
> + if (err)
> + return err;
> +
> + *handle = gem_create.handle;
> + return 0;
> +}
> +
> +static int i915_mmap_offset(struct dri *dri, uint32_t handle, uint64_t *offset)
> +{
> + struct drm_i915_gem_mmap_gtt gem_mmap = {0};
> + int err;
> +
> + gem_mmap.handle = handle;
> + err = ioctl(dri->fd, DRM_IOCTL_I915_GEM_MMAP_GTT, &gem_mmap);
> + if (err)
> + return err;
> +
> + *offset = gem_mmap.offset;
> + return 0;
> +}
> +
> +static int amdgpu_mmap_offset(struct dri *dri, uint32_t handle
> + uint64_t *offset)
> +{
> + union drm_amdgpu_gem_mmap gem_mmap = {{0}};
> + int err;
> +
> + gem_mmap.in.handle = handle;
> + err = ioctl(dri->fd, DRM_IOCTL_AMDGPU_GEM_MMAP, &gem_mmap);
> + if (err)
> + return err;
> +
> + *offset = gem_mmap.out.addr_ptr;
> + return 0;
> +}
> +
> +static int radeon_mmap_offset(struct dri *dri, uint32_t handle,
> + uint64_t *offset)
> +{
> + struct drm_radeon_gem_mmap gem_mmap = {0};
> + int err;
> +
> + gem_mmap.handle = handle;
> + err = ioctl(dri->fd, DRM_IOCTL_RADEON_GEM_MMAP, &gem_mmap);
> + if (err)
> + return err;
> +
> + *offset = gem_mmap.addr_ptr;
> + return 0;
> +}
> +
> +static struct dri *dri_open(int unit)
> +{
> + char path[32];
> + struct drm_version version = {0};
> + char name[16] = {0};
> + int err;
> + struct dri *dri;
> +
> + dri = malloc(sizeof(*dri));
> + if (!dri)
> + return NULL;
> +
> + sprintf(path, "/dev/dri/renderD%d", unit + 128);
> +
> + dri->fd = open(path, O_RDWR);
> + if (dri->fd < 0)
> + goto out_free;
> +
> + version.name = name;
> + version.name_len = 16;
> + err = ioctl(dri->fd, DRM_IOCTL_VERSION, &version);
> + if (err)
> + goto out_close;
> +
> + if (!strcmp(name, "amdgpu")) {
> + dri->alloc = amdgpu_alloc;
> + dri->mmap_offset = amdgpu_mmap_offset;
> + } else if (!strcmp(name, "i915")) {
> + dri->alloc = i915_alloc;
> + dri->mmap_offset = i915_mmap_offset;
> + } else if (!strcmp(name, "radeon")) {
> + dri->alloc = radeon_alloc;
> + dri->mmap_offset = radeon_mmap_offset;
> + } else {
> + goto out_close;
> + }
> + return dri;
> +
> +out_close:
> + close(dri->fd);
> +
> +out_free:
> + free(dri);
> + return NULL;
> +}
> +
> +static void dri_close(struct dri *dri)
> +{
> + if (!dri || dri->fd < 0)
> + return;
> +
> + close(dri->fd);
> + free(dri);
> +}
> +
> +static void dri_free_buf(struct dri *dri, uint32_t handle)
> +{
> + struct drm_gem_close close = {0};
> +
> + close.handle = handle;
> + ioctl(dri->fd, DRM_IOCTL_GEM_CLOSE, &close);
> +}
> +
> +static int dri_alloc_buf(struct dri *dri, size_t size, uint32_t *handle, int *fd)
> +{
> + struct drm_prime_handle prime_handle = {0};
> + int err;
> +
> + if (!dri || dri->fd < 0)
> + return -EINVAL;
> +
> + err = dri->alloc(dri, size, handle);
> + if (err)
> + return err;
> +
> + prime_handle.handle = *handle;
> + prime_handle.flags = O_RDWR;
> + err = ioctl(dri->fd, DRM_IOCTL_PRIME_HANDLE_TO_FD, &prime_handle);
> + if (err) {
> + dri_free_buf(dri, *handle);
> + return err;
> + }
> +
> + *fd = prime_handle.fd;
> + return 0;
> +}
> +
> +static int dri_map_buf(struct dri *dri, uint32_t handle, uint64_t *offset)
> +{
> + if (!dri || dri->fd < 0)
> + return -EINVAL;
> +
> + return dri->mmap_offset(dri, handle, offset);
> +}
> +
> +/*
> + * Abstraction of dmabuf object, allocated using the DRI abstraction defined
> + * above.
> + */
> +
> +struct dmabuf {
> + struct dri *dri;
> + int fd;
> + uint32_t handle;
> + uint64_t map_offset;
> +};
> +
> +struct dmabuf *dmabuf_alloc(uint64_t size, int unit)
> +{
> + struct dmabuf *dmabuf;
> + int err;
> +
> + dmabuf = malloc(sizeof *dmabuf);
> + if (!dmabuf)
> + return NULL;
> +
> + dmabuf->dri = dri_open(unit);
> + if (!dmabuf->dri)
> + goto out_free;
> +
> + err = dri_alloc_buf(dmabuf->dri, size, &dmabuf->handle, &dmabuf->fd);
> + if (err)
> + goto out_close;
> +
> + err = dri_map_buf(dmabuf->dri, dmabuf->handle, &dmabuf->map_offset);
> + if (err)
> + goto out_free_buf;
> +
> + return dmabuf;
> +
> +out_free_buf:
> + dri_free_buf(dmabuf->dri, dmabuf->handle);
> +
> +out_close:
> + dri_close(dmabuf->dri);
> +
> +out_free:
> + free(dmabuf);
> + return NULL;
> +}
> +
> +void dmabuf_free(struct dmabuf *dmabuf)
> +{
> + if (!dmabuf)
> + return;
> +
> + close(dmabuf->fd);
> + dri_free_buf(dmabuf->dri, dmabuf->handle);
> + dri_close(dmabuf->dri);
> + free(dmabuf);
> +}
> +
> +int dmabuf_get_dri_fd(struct dmabuf *dmabuf)
> +{
> + if (!dmabuf || !dmabuf->dri)
> + return -1;
> +
> + return dmabuf->dri->fd;
> +}
> +
> +int dmabuf_get_fd(struct dmabuf *dmabuf)
> +{
> + if (!dmabuf)
> + return -1;
> +
> + return dmabuf->fd;
> +}
> +
> +uint64_t dmabuf_get_offset(struct dmabuf *dmabuf)
> +{
> + if (!dmabuf)
> + return -1;
> +
> + return dmabuf->map_offset;
> +}
> +
> diff --git a/pyverbs/dmabuf_alloc.h b/pyverbs/dmabuf_alloc.h
> new file mode 100644
> index 0000000..f36c337
> --- /dev/null
> +++ b/pyverbs/dmabuf_alloc.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
> +/*
> + * Copyright 2020 Intel Corporation. All rights reserved. See COPYING file
> + */
> +
> +#ifndef _DRI_H_
> +#define _DRI_H_
> +
> +#include <stdint.h>
> +
> +struct dmabuf;
> +
> +struct dmabuf *dmabuf_alloc(uint64_t size, int unit);
> +void dmabuf_free(struct dmabuf *dmabuf);
> +int dmabuf_get_dri_fd(struct dmabuf *dmabuf);
> +int dmabuf_get_fd(struct dmabuf *dmabuf);
> +uint64_t dmabuf_get_offset(struct dmabuf *dmabuf);
> +
> +#endif /* _DRI_H_ */
> diff --git a/pyverbs/libibverbs.pxd b/pyverbs/libibverbs.pxd
> index 6fbba54..d76f633 100644
> --- a/pyverbs/libibverbs.pxd
> +++ b/pyverbs/libibverbs.pxd
> @@ -507,6 +507,8 @@ cdef extern from 'infiniband/verbs.h':
> ibv_pd *ibv_alloc_pd(ibv_context *context)
> int ibv_dealloc_pd(ibv_pd *pd)
> ibv_mr *ibv_reg_mr(ibv_pd *pd, void *addr, size_t length, int access)
> + ibv_mr *ibv_reg_dmabuf_mr(ibv_pd *pd, uint64_t offset, size_t length,
> + uint64_t iova, int fd, int access)
> int ibv_dereg_mr(ibv_mr *mr)
> int ibv_advise_mr(ibv_pd *pd, uint32_t advice, uint32_t flags,
> ibv_sge *sg_list, uint32_t num_sge)
> diff --git a/pyverbs/mr.pxd b/pyverbs/mr.pxd
> index ebe8ada..d9a79ff 100644
> --- a/pyverbs/mr.pxd
> +++ b/pyverbs/mr.pxd
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB)
> # Copyright (c) 2019, Mellanox Technologies. All rights reserved. See COPYING file
> +# Copyright (c) 2020, Intel Corporation. All rights reserved. See COPYING file
>
> #cython: language_level=3
>
> @@ -33,3 +34,8 @@ cdef class MW(PyverbsCM):
>
> cdef class DMMR(MR):
> cdef object dm
> +
> +cdef class DmaBufMR(MR):
> + cdef object dmabuf
> + cdef unsigned long offset
> + cdef object is_dmabuf_internal
> diff --git a/pyverbs/mr.pyx b/pyverbs/mr.pyx
> index 7011da1..e4ed2dc 100644
> --- a/pyverbs/mr.pyx
> +++ b/pyverbs/mr.pyx
> @@ -1,11 +1,12 @@
> # SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB)
> # Copyright (c) 2019, Mellanox Technologies. All rights reserved. See COPYING file
> +# Copyright (c) 2020, Intel Corporation. All rights reserved. See COPYING file
>
> import resource
> import logging
>
> from posix.mman cimport mmap, munmap, MAP_PRIVATE, PROT_READ, PROT_WRITE, \
> - MAP_ANONYMOUS, MAP_HUGETLB
> + MAP_ANONYMOUS, MAP_HUGETLB, MAP_SHARED
> from pyverbs.pyverbs_error import PyverbsError, PyverbsRDMAError, \
> PyverbsUserError
> from libc.stdint cimport uintptr_t, SIZE_MAX
> @@ -14,9 +15,10 @@ from posix.stdlib cimport posix_memalign
> from libc.string cimport memcpy, memset
> cimport pyverbs.libibverbs_enums as e
> from pyverbs.device cimport DM
> -from libc.stdlib cimport free
> +from libc.stdlib cimport free, malloc
> from .cmid cimport CMID
> from .pd cimport PD
> +from .dmabuf cimport DmaBuf
>
> cdef extern from 'sys/mman.h':
> cdef void* MAP_FAILED
> @@ -348,6 +350,103 @@ cdef class DMMR(MR):
> cpdef read(self, length, offset):
> return self.dm.copy_from_dm(offset, length)
>
> +cdef class DmaBufMR(MR):
> + def __init__(self, PD pd not None, length, access, DmaBuf dmabuf=None,
> + offset=0):
> + """
> + Initializes a DmaBufMR (DMA-BUF Memory Region) of the given length
> + and access flags using the given PD and DmaBuf objects.
> + :param pd: A PD object
> + :param length: Length in bytes
> + :param access: Access flags, see ibv_access_flags enum
> + :param dmabuf: A DmaBuf object. One will be allocated if absent
> + :param offset: Byte offset from the beginning of the dma-buf
> + :return: The newly created DMABUFMR
> + """
> + self.logger = logging.getLogger(self.__class__.__name__)
> + if dmabuf is None:
> + self.is_dmabuf_internal = True
> + dmabuf = DmaBuf(length + offset)
> + self.mr = v.ibv_reg_dmabuf_mr(pd.pd, offset, length, offset, dmabuf.fd, access)
> + if self.mr == NULL:
> + raise PyverbsRDMAErrno(f'Failed to register a dma-buf MR. length: {length}, access flags: {access}')
> + super().__init__(pd, length, access)
> + self.pd = pd
> + self.dmabuf = dmabuf
> + self.offset = offset
> + pd.add_ref(self)
> + dmabuf.add_ref(self)
> + self.logger.debug(f'Registered dma-buf ibv_mr. Length: {length}, access flags {access}')
> +
> + def __dealloc__(self):
> + self.close()
> +
> + cpdef close(self):
> + """
> + Closes the underlying C object of the MR and frees the memory allocated.
> + :return: None
> + """
> + if self.mr != NULL:
> + self.logger.debug('Closing dma-buf MR')
> + rc = v.ibv_dereg_mr(self.mr)
> + if rc != 0:
> + raise PyverbsRDMAError('Failed to dereg dma-buf MR', rc)
> + self.pd = None
> + self.mr = NULL
> + # Set self.mr to NULL before closing dmabuf because this method is
> + # re-entered when close_weakrefs() is called inside dmabuf.close().
> + if self.is_dmabuf_internal:
> + self.dmabuf.close()
> + self.dmabuf = None
> +
> + @property
> + def offset(self):
> + return self.offset
> +
> + @property
> + def dmabuf(self):
> + return self.dmabuf
> +
> + def write(self, data, length, offset=0):
> + """
> + Write user data to the dma-buf backing the MR
> + :param data: User data to write
> + :param length: Length of the data to write
> + :param offset: Writing offset
> + :return: None
> + """
> + if isinstance(data, str):
> + data = data.encode()
> + cdef int off = offset + self.offset
> + cdef void *buf = mmap(NULL, length + off, PROT_READ | PROT_WRITE,
> + MAP_SHARED, self.dmabuf.dri_fd,
> + self.dmabuf.map_offset)
> + if buf == MAP_FAILED:
> + raise PyverbsError(f'Failed to map dma-buf of size {length}')
> + memcpy(<char*>(buf + off), <char *>data, length)
> + munmap(buf, length + off)
> +
> + cpdef read(self, length, offset):
Note reads are generally uncached so really slow. Maybe put that as a
warning somewhere.
> + """
> + Reads data from the dma-buf backing the MR
> + :param length: Length of data to read
> + :param offset: Reading offset
> + :return: The data on the buffer in the requested offset
> + """
> + cdef int off = offset + self.offset
> + cdef void *buf = mmap(NULL, length + off, PROT_READ | PROT_WRITE,
> + MAP_SHARED, self.dmabuf.dri_fd,
> + self.dmabuf.map_offset)
> + if buf == MAP_FAILED:
> + raise PyverbsError(f'Failed to map dma-buf of size {length}')
> + cdef char *data =<char*>malloc(length)
> + memset(data, 0, length)
> + memcpy(data, <char*>(buf + off), length)
> + munmap(buf, length + off)
> + res = data[:length]
> + free(data)
> + return res
> +
>
> def mwtype2str(mw_type):
> mw_types = {1:'IBV_MW_TYPE_1', 2:'IBV_MW_TYPE_2'}
gpu side looks reasonable.
One bikeshed maybe: Kernel gpu drivers are drm (for direct rendering
manager). DRI is the X11 protocols to support glx direct rendering (i.e.
it's direct rendering infrastructure). devnodes being put into dri is an
unfortunate historical accident. I'd rename all the dri_ to drm_ for
consistency with other drm users, e.g. libdrm.
Cheers, Daniel
> --
> 1.8.3.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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