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2d2db7d4 |
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06-Jan-2024 |
Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> |
xen/gntdev: Fix the abuse of underlying struct page in DMA-buf import DO NOT access the underlying struct page of an sg table exported by DMA-buf in dmabuf_imp_to_refs(), this is not allowed. Please see drivers/dma-buf/dma-buf.c:mangle_sg_table() for details. Fortunately, here (for special Xen device) we can avoid using pages and calculate gfns directly from dma addresses provided by the sg table. Suggested-by: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Acked-by: Christian König <christian.koenig@amd.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Acked-by: Daniel Vetter <daniel@ffwll.ch> Link: https://lore.kernel.org/r/20240107103426.2038075-1-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
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e841ad86 |
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17-Oct-2022 |
Dmitry Osipenko <dmitry.osipenko@collabora.com> |
xen/gntdev: Prepare to dynamic dma-buf locking specification Prepare gntdev driver to the common dynamic dma-buf locking convention by starting to use the unlocked versions of dma-buf API functions. Acked-by: Juergen Gross <jgross@suse.com> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-13-dmitry.osipenko@collabora.com
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49f8b459 |
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24-May-2022 |
Juergen Gross <jgross@suse.com> |
xen: switch gnttab_end_foreign_access() to take a struct page pointer Instead of a virtual kernel address use a pointer of the associated struct page as second parameter of gnttab_end_foreign_access(). Most users have that pointer available already and are creating the virtual address from it, risking problems in case the memory is located in highmem. gnttab_end_foreign_access() itself won't need to get the struct page from the address again. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
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bd506c78 |
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28-Apr-2022 |
Juergen Gross <jgross@suse.com> |
xen/dmabuf: switch gntdev-dmabuf to use INVALID_GRANT_REF Instead of using a private macro for an invalid grant reference use the common one. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
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c94b731d |
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11-Mar-2022 |
Juergen Gross <jgross@suse.com> |
xen/grant-table: remove readonly parameter from functions The gnttab_end_foreign_access() family of functions is taking a "readonly" parameter, which isn't used. Remove it from the function parameters. Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20220311103429.12845-3-jgross@suse.com Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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16b0314a |
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10-Oct-2021 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
dma-buf: move dma-buf symbols into the DMA_BUF module namespace In order to better track where in the kernel the dma-buf code is used, put the symbols in the namespace DMA_BUF and modify all users of the symbols to properly import the namespace to not break the build at the same time. Now the output of modinfo shows the use of these symbols, making it easier to watch for users over time: $ modinfo drivers/misc/fastrpc.ko | grep import import_ns: DMA_BUF Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Alex Deucher <alexander.deucher@amd.com> Link: https://lore.kernel.org/r/20211010124628.17691-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d1749eb1 |
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08-May-2020 |
Marek Szyprowski <m.szyprowski@samsung.com> |
xen: gntdev: fix common struct sg_table related issues The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Juergen Gross <jgross@suse.com>
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5fa4e6f1 |
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13-Aug-2020 |
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
xen/gntdev: Fix dmabuf import with non-zero sgt offset It is possible that the scatter-gather table during dmabuf import has non-zero offset of the data, but user-space doesn't expect that. Fix this by failing the import, so user-space doesn't access wrong data. Fixes: bf8dc55b1358 ("xen/gntdev: Implement dma-buf import functionality") Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200813062113.11030-2-andr2000@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
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3b06ac67 |
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06-Nov-2019 |
Juergen Gross <jgross@suse.com> |
xen/gntdev: replace global limit of mapped pages by limit per call Today there is a global limit of pages mapped via /dev/xen/gntdev set to 1 million pages per default. There is no reason why that limit is existing, as total number of grant mappings is limited by the hypervisor anyway and preferring kernel mappings over userspace ones doesn't make sense. It should be noted that the gntdev device is usable by root only. Additionally checking of that limit is fragile, as the number of pages to map via one call is specified in a 32-bit unsigned variable which isn't tested to stay within reasonable limits (the only test is the value to be <= zero, which basically excludes only calls without any mapping requested). So trying to map e.g. 0xffff0000 pages while already nearly 1000000 pages are mapped will effectively lower the global number of mapped pages such that a parallel call mapping a reasonable amount of pages can succeed in spite of the global limit being violated. So drop the global limit and introduce per call limit instead. This per call limit (default: 65536 grant mappings) protects against allocating insane large arrays in the kernel for doing a hypercall which will fail anyway in case a user is e.g. trying to map billions of pages. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
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dea8c09c |
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18-Nov-2019 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
xen/gntdev-dmabuf: Ditch dummy map functions There's no in-kernel users for the k(un)map stuff. And the mmap one is actively harmful - return 0 and then _not_ actually mmaping can't end well. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://patchwork.freedesktop.org/patch/msgid/20191118103536.17675-14-daniel.vetter@ffwll.ch
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068e79f4 |
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14-Feb-2019 |
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
xen/gntdev: Check and release imported dma-bufs on close Check if there are any imported dma-bufs left not released by user-space when grant device's release callback is called and free those if this is the case. This can happen if user-space leaks the buffers because of a bug or application has been terminated for any reason. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
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fa13e665 |
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14-Feb-2019 |
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
xen/gntdev: Do not destroy context while dma-bufs are in use If there are exported DMA buffers which are still in use and grant device is closed by either normal user-space close or by a signal this leads to the grant device context to be destroyed, thus making it not possible to correctly destroy those exported buffers when they are returned back to gntdev and makes the module crash: [ 339.617540] [<ffff00000854c0d8>] dmabuf_exp_ops_release+0x40/0xa8 [ 339.617560] [<ffff00000867a6e8>] dma_buf_release+0x60/0x190 [ 339.617577] [<ffff0000082211f0>] __fput+0x88/0x1d0 [ 339.617589] [<ffff000008221394>] ____fput+0xc/0x18 [ 339.617607] [<ffff0000080ed4e4>] task_work_run+0x9c/0xc0 [ 339.617622] [<ffff000008089714>] do_notify_resume+0xfc/0x108 Fix this by referencing gntdev on each DMA buffer export and unreferencing on buffer release. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
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2789e83c |
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31-Jul-2018 |
Colin Ian King <colin.king@canonical.com> |
xen/gntdev: don't dereference a null gntdev_dmabuf on allocation failure Currently when the allocation of gntdev_dmabuf fails, the error exit path will call dmabuf_imp_free_storage and causes a null pointer dereference on gntdev_dmabuf. Fix this by adding an error exit path that won't free gntdev_dmabuf. Detected by CoverityScan, CID#1472124 ("Dereference after null check") Fixes: bf8dc55b1358 ("xen/gntdev: Implement dma-buf import functionality") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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bf8dc55b |
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19-Jul-2018 |
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
xen/gntdev: Implement dma-buf import functionality 1. Import a dma-buf with the file descriptor provided and export granted references to the pages of that dma-buf into the array of grant references. 2. Add API to close all references to an imported buffer, so it can be released by the owner. This is only valid for buffers created with IOCTL_GNTDEV_DMABUF_IMP_TO_REFS. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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a240d6e4 |
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19-Jul-2018 |
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
xen/gntdev: Implement dma-buf export functionality 1. Create a dma-buf from grant references provided by the foreign domain. By default dma-buf is backed by system memory pages, but by providing GNTDEV_DMA_FLAG_XXX flags it can also be created as a DMA write-combine/coherent buffer, e.g. allocated with corresponding dma_alloc_xxx API. Export the resulting buffer as a new dma-buf. 2. Implement waiting for the dma-buf to be released: block until the dma-buf with the file descriptor provided is released. If within the time-out provided the buffer is not released then -ETIMEDOUT error is returned. If the buffer with the file descriptor does not exist or has already been released, then -ENOENT is returned. For valid file descriptors this must not be treated as error. 3. Make gntdev's common code and structures available to dma-buf. [boris: added 'args.fd = -1' to dmabuf_exp_from_refs() to avoid an unnecessary warning about it not being initialized on i386 with gcc 8.1.1] Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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932d6562 |
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19-Jul-2018 |
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
xen/gntdev: Add initial support for dma-buf UAPI Add UAPI and IOCTLs for dma-buf grant device driver extension: the extension allows userspace processes and kernel modules to use Xen backed dma-buf implementation. With this extension grant references to the pages of an imported dma-buf can be exported for other domain use and grant references coming from a foreign domain can be converted into a local dma-buf for local export. Implement basic initialization and stubs for Xen DMA buffers' support. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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