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Re: [PATCH bpf-next v4 4/5] selftests/bpf: Add test for dmabuf_iter

by T.J. Mercier

On Thu, May 8, 2025 at 5:36 PM Song Liu <song(a)kernel.org> wrote: > > On Thu, May 8, 2025 at 11:20 AM T.J. Mercier <tjmercier(a)google.com> wrote: > [...] > > diff --git a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c > > new file mode 100644 > > index 000000000000..35745f4ce0f8 > > --- /dev/null > > +++ b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c > > @@ -0,0 +1,224 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* Copyright (c) 2025 Google */ > > + > > +#include <test_progs.h> > > +#include <bpf/libbpf.h> > > +#include <bpf/btf.h> > > +#include "dmabuf_iter.skel.h" > > + > > +#include <fcntl.h> > > +#include <stdbool.h> > > +#include <stdio.h> > > +#include <stdlib.h> > > +#include <string.h> > > +#include <sys/ioctl.h> > > +#include <sys/mman.h> > > +#include <unistd.h> > > + > > +#include <linux/dma-buf.h> > > +#include <linux/dma-heap.h> > > +#include <linux/udmabuf.h> > > + > > +static int memfd, udmabuf; > > Global fds are weird. AFAICT, we don't really need them > to be global? If we really need them to be global, please > initialize them to -1, just in case we close(0) by accident. Hmm, no we don't really need them to be global but I didn't really want to pass all these variables around to all the setup and test functions. The fd lifetimes are nearly the whole program lifetime anyways, and just need to exist without actually being used for anything. I'll add the -1 initialization as you suggest. If udmabuf creation failed, we would have done a close(0) in destroy_test_buffers() on the sysheap_dmabuf fd. > > +static const char udmabuf_test_buffer_name[DMA_BUF_NAME_LEN] = "udmabuf_test_buffer_for_iter"; > > +static size_t udmabuf_test_buffer_size; > > +static int sysheap_dmabuf; > > +static const char sysheap_test_buffer_name[DMA_BUF_NAME_LEN] = "sysheap_test_buffer_for_iter"; > > +static size_t sysheap_test_buffer_size;

4 months

Re: [PATCH bpf-next v4 3/5] bpf: Add open coded dmabuf iterator

by T.J. Mercier

On Thu, May 8, 2025 at 5:28 PM Song Liu <song(a)kernel.org> wrote: > > On Thu, May 8, 2025 at 11:20 AM T.J. Mercier <tjmercier(a)google.com> wrote: > > > > This open coded iterator allows for more flexibility when creating BPF > > programs. It can support output in formats other than text. With an open > > coded iterator, a single BPF program can traverse multiple kernel data > > structures (now including dmabufs), allowing for more efficient analysis > > of kernel data compared to multiple reads from procfs, sysfs, or > > multiple traditional BPF iterator invocations. > > > > Signed-off-by: T.J. Mercier <tjmercier(a)google.com> > > Acked-by: Song Liu <song(a)kernel.org> > > With one nitpick below: > > > --- > > kernel/bpf/dmabuf_iter.c | 47 ++++++++++++++++++++++++++++++++++++++++ > > kernel/bpf/helpers.c | 5 +++++ > > 2 files changed, 52 insertions(+) > > > > diff --git a/kernel/bpf/dmabuf_iter.c b/kernel/bpf/dmabuf_iter.c > > index 96b4ba7f0b2c..8049bdbc9efc 100644 > > --- a/kernel/bpf/dmabuf_iter.c > > +++ b/kernel/bpf/dmabuf_iter.c > > @@ -100,3 +100,50 @@ static int __init dmabuf_iter_init(void) > > } > > > > late_initcall(dmabuf_iter_init); > > + > > +struct bpf_iter_dmabuf { > > + /* opaque iterator state; having __u64 here allows to preserve correct > > + * alignment requirements in vmlinux.h, generated from BTF > > + */ > > nit: comment style. Added a leading /* (This is copied from task_iter.c, which currently has the same style.) > > + __u64 __opaque[1]; > > +} __aligned(8); > > + > > +/* Non-opaque version of bpf_iter_dmabuf */ > > +struct bpf_iter_dmabuf_kern { > > + struct dma_buf *dmabuf; > > +} __aligned(8); > > + > [...]

4 months

Re: [PATCH bpf-next v4 2/5] bpf: Add dmabuf iterator

by T.J. Mercier

On Thu, May 8, 2025 at 5:27 PM Song Liu <song(a)kernel.org> wrote: > > On Thu, May 8, 2025 at 11:20 AM T.J. Mercier <tjmercier(a)google.com> wrote: > > > > The dmabuf iterator traverses the list of all DMA buffers. > > > > DMA buffers are refcounted through their associated struct file. A > > reference is taken on each buffer as the list is iterated to ensure each > > buffer persists for the duration of the bpf program execution without > > holding the list mutex. > > > > Signed-off-by: T.J. Mercier <tjmercier(a)google.com> > > Reviewed-by: Christian König <christian.koenig(a)amd.com> > > Acked-by: Song Liu <song(a)kernel.org> > > With one nitpick below. Thanks! > > --- > [...] > > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > > index 8ff4add71f88..7af2ea839f58 100644 > > --- a/include/linux/dma-buf.h > > +++ b/include/linux/dma-buf.h > > @@ -634,4 +634,6 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map); > > void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map); > > int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map); > > void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map); > > +struct dma_buf *dma_buf_iter_begin(void); > > +struct dma_buf *dma_buf_iter_next(struct dma_buf *dmbuf); > > #endif /* __DMA_BUF_H__ */ > > diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile > > index 70502f038b92..3a335c50e6e3 100644 > > --- a/kernel/bpf/Makefile > > +++ b/kernel/bpf/Makefile > > @@ -53,6 +53,9 @@ obj-$(CONFIG_BPF_SYSCALL) += relo_core.o > > obj-$(CONFIG_BPF_SYSCALL) += btf_iter.o > > obj-$(CONFIG_BPF_SYSCALL) += btf_relocate.o > > obj-$(CONFIG_BPF_SYSCALL) += kmem_cache_iter.o > > +ifeq ($(CONFIG_DMA_SHARED_BUFFER),y) > > +obj-$(CONFIG_BPF_SYSCALL) += dmabuf_iter.o > > +endif > > > > CFLAGS_REMOVE_percpu_freelist.o = $(CC_FLAGS_FTRACE) > > CFLAGS_REMOVE_bpf_lru_list.o = $(CC_FLAGS_FTRACE) > > diff --git a/kernel/bpf/dmabuf_iter.c b/kernel/bpf/dmabuf_iter.c > > new file mode 100644 > > index 000000000000..96b4ba7f0b2c > > --- /dev/null > > +++ b/kernel/bpf/dmabuf_iter.c > > @@ -0,0 +1,102 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* Copyright (c) 2025 Google LLC */ > > +#include <linux/bpf.h> > > +#include <linux/btf_ids.h> > > +#include <linux/dma-buf.h> > > +#include <linux/kernel.h> > > +#include <linux/seq_file.h> > > + > > +BTF_ID_LIST_SINGLE(bpf_dmabuf_btf_id, struct, dma_buf) > > +DEFINE_BPF_ITER_FUNC(dmabuf, struct bpf_iter_meta *meta, struct dma_buf *dmabuf) > > nit: It is better to move these two lines later, to where they > are about to be used. I've moved them both to just before dmabuf_iter_init() farther down.

4 months

[PATCH bpf-next v4 0/5] Replace CONFIG_DMABUF_SYSFS_STATS with BPF

by T.J. Mercier

Until CONFIG_DMABUF_SYSFS_STATS was added [1] it was only possible to perform per-buffer accounting with debugfs which is not suitable for production environments. Eventually we discovered the overhead with per-buffer sysfs file creation/removal was significantly impacting allocation and free times, and exacerbated kernfs lock contention. [2] dma_buf_stats_setup() is responsible for 39% of single-page buffer creation duration, or 74% of single-page dma_buf_export() duration when stressing dmabuf allocations and frees. I prototyped a change from per-buffer to per-exporter statistics with a RCU protected list of exporter allocations that accommodates most (but not all) of our use-cases and avoids almost all of the sysfs overhead. While that adds less overhead than per-buffer sysfs, and less even than the maintenance of the dmabuf debugfs_list, it's still *additional* overhead on top of the debugfs_list and doesn't give us per-buffer info. This series uses the existing dmabuf debugfs_list to implement a BPF dmabuf iterator, which adds no overhead to buffer allocation/free and provides per-buffer info. The list has been moved outside of CONFIG_DEBUG_FS scope so that it is always populated. The BPF program loaded by userspace that extracts per-buffer information gets to define its own interface which avoids the lack of ABI stability with debugfs. This will allow us to replace our use of CONFIG_DMABUF_SYSFS_STATS, and the plan is to remove it from the kernel after the next longterm stable release. [1] https://lore.kernel.org/linux-media/20201210044400.1080308-1-hridya@google.… [2] https://lore.kernel.org/all/20220516171315.2400578-1-tjmercier@google.com v1: https://lore.kernel.org/all/20250414225227.3642618-1-tjmercier@google.com v1 -> v2: Make the DMA buffer list independent of CONFIG_DEBUG_FS per Christian König Add CONFIG_DMA_SHARED_BUFFER check to kernel/bpf/Makefile per kernel test robot Use BTF_ID_LIST_SINGLE instead of BTF_ID_LIST_GLOBAL_SINGLE per Song Liu Fixup comment style, mixing code/declarations, and use ASSERT_OK_FD in selftest per Song Liu Add BPF_ITER_RESCHED feature to bpf_dmabuf_reg_info per Alexei Starovoitov Add open-coded iterator and selftest per Alexei Starovoitov Add a second test buffer from the system dmabuf heap to selftests Use the BPF program we'll use in production for selftest per Alexei Starovoitov https://r.android.com/c/platform/system/bpfprogs/+/3616123/2/dmabufIter.c https://r.android.com/c/platform/system/memory/libmeminfo/+/3614259/1/libdm… v2: https://lore.kernel.org/all/20250504224149.1033867-1-tjmercier@google.com v2 -> v3: Rebase onto bpf-next/master Move get_next_dmabuf() into drivers/dma-buf/dma-buf.c, along with the new get_first_dmabuf(). This avoids having to expose the dmabuf list and mutex to the rest of the kernel, and keeps the dmabuf mutex operations near each other in the same file. (Christian König) Add Christian's RB to dma-buf: Rename debugfs symbols Drop RFC: dma-buf: Remove DMA-BUF statistics v3: https://lore.kernel.org/all/20250507001036.2278781-1-tjmercier@google.com v3 -> v4: Fix selftest BPF program comment style (not kdoc) per Alexei Starovoitov Fix dma-buf.c kdoc comment style per Alexei Starovoitov Rename get_first_dmabuf / get_next_dmabuf to dma_buf_iter_begin / dma_buf_iter_next per Christian König Add Christian's RB to bpf: Add dmabuf iterator T.J. Mercier (5): dma-buf: Rename debugfs symbols bpf: Add dmabuf iterator bpf: Add open coded dmabuf iterator selftests/bpf: Add test for dmabuf_iter selftests/bpf: Add test for open coded dmabuf_iter drivers/dma-buf/dma-buf.c | 98 +++++-- include/linux/dma-buf.h | 4 +- kernel/bpf/Makefile | 3 + kernel/bpf/dmabuf_iter.c | 149 ++++++++++ kernel/bpf/helpers.c | 5 + .../testing/selftests/bpf/bpf_experimental.h | 5 + tools/testing/selftests/bpf/config | 3 + .../selftests/bpf/prog_tests/dmabuf_iter.c | 258 ++++++++++++++++++ .../testing/selftests/bpf/progs/dmabuf_iter.c | 91 ++++++ 9 files changed, 594 insertions(+), 22 deletions(-) create mode 100644 kernel/bpf/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/progs/dmabuf_iter.c base-commit: 43745d11bfd9683abdf08ad7a5cc403d6a9ffd15 -- 2.49.0.1015.ga840276032-goog

4 months

Re: [PATCH] dma-buf/sw-sync: Remove unused debug code

by Christian König

On 5/6/25 01:38, linux(a)treblig.org wrote: > From: "Dr. David Alan Gilbert" <linux(a)treblig.org> > > sync_file_debug_add() and sync_file_debug_remove() have been unused > since 2016's > commit d4cab38e153d ("staging/android: prepare sync_file for de-staging") > > Remove them. > > Since sync_file_debug_add was the only thing to add to > sync_file_list_head, the code that dumps it in part of > sync_info_debugfs_show can be removed, and the declaration of > the list and it's associated lock can be removed. > (The 'fences:\n...' marker in that debugfs file is left in > so as not to change the output) > > That leaves the sync_print_sync_file() helper unused, and > is thus removed. > > Signed-off-by: Dr. David Alan Gilbert <linux(a)treblig.org> I've added my reviewed-by and pushed it into drm-misc-next for upstreaming. Thanks, Christian. > --- > drivers/dma-buf/sync_debug.c | 49 ------------------------------------ > drivers/dma-buf/sync_debug.h | 2 -- > 2 files changed, 51 deletions(-) > > diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c > index 237bce21d1e7..a9c3312dc85d 100644 > --- a/drivers/dma-buf/sync_debug.c > +++ b/drivers/dma-buf/sync_debug.c > @@ -12,8 +12,6 @@ static struct dentry *dbgfs; > > static LIST_HEAD(sync_timeline_list_head); > static DEFINE_SPINLOCK(sync_timeline_list_lock); > -static LIST_HEAD(sync_file_list_head); > -static DEFINE_SPINLOCK(sync_file_list_lock); > > void sync_timeline_debug_add(struct sync_timeline *obj) > { > @@ -33,24 +31,6 @@ void sync_timeline_debug_remove(struct sync_timeline *obj) > spin_unlock_irqrestore(&sync_timeline_list_lock, flags); > } > > -void sync_file_debug_add(struct sync_file *sync_file) > -{ > - unsigned long flags; > - > - spin_lock_irqsave(&sync_file_list_lock, flags); > - list_add_tail(&sync_file->sync_file_list, &sync_file_list_head); > - spin_unlock_irqrestore(&sync_file_list_lock, flags); > -} > - > -void sync_file_debug_remove(struct sync_file *sync_file) > -{ > - unsigned long flags; > - > - spin_lock_irqsave(&sync_file_list_lock, flags); > - list_del(&sync_file->sync_file_list); > - spin_unlock_irqrestore(&sync_file_list_lock, flags); > -} > - > static const char *sync_status_str(int status) > { > if (status < 0) > @@ -118,26 +98,6 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj) > spin_unlock(&obj->lock); > } > > -static void sync_print_sync_file(struct seq_file *s, > - struct sync_file *sync_file) > -{ > - char buf[128]; > - int i; > - > - seq_printf(s, "[%p] %s: %s\n", sync_file, > - sync_file_get_name(sync_file, buf, sizeof(buf)), > - sync_status_str(dma_fence_get_status(sync_file->fence))); > - > - if (dma_fence_is_array(sync_file->fence)) { > - struct dma_fence_array *array = to_dma_fence_array(sync_file->fence); > - > - for (i = 0; i < array->num_fences; ++i) > - sync_print_fence(s, array->fences[i], true); > - } else { > - sync_print_fence(s, sync_file->fence, true); > - } > -} > - > static int sync_info_debugfs_show(struct seq_file *s, void *unused) > { > struct list_head *pos; > @@ -157,15 +117,6 @@ static int sync_info_debugfs_show(struct seq_file *s, void *unused) > > seq_puts(s, "fences:\n--------------\n"); > > - spin_lock_irq(&sync_file_list_lock); > - list_for_each(pos, &sync_file_list_head) { > - struct sync_file *sync_file = > - container_of(pos, struct sync_file, sync_file_list); > - > - sync_print_sync_file(s, sync_file); > - seq_putc(s, '\n'); > - } > - spin_unlock_irq(&sync_file_list_lock); > return 0; > } > > diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h > index a1bdd62efccd..02af347293d0 100644 > --- a/drivers/dma-buf/sync_debug.h > +++ b/drivers/dma-buf/sync_debug.h > @@ -68,7 +68,5 @@ extern const struct file_operations sw_sync_debugfs_fops; > > void sync_timeline_debug_add(struct sync_timeline *obj); > void sync_timeline_debug_remove(struct sync_timeline *obj); > -void sync_file_debug_add(struct sync_file *fence); > -void sync_file_debug_remove(struct sync_file *fence); > > #endif /* _LINUX_SYNC_H */

4 months

Re: [PATCH 4/4] drm/nouveau: Check dma_fence in canonical way

by Christian König

On 5/8/25 11:13, Philipp Stanner wrote: > On Mon, 2025-04-28 at 16:45 +0200, Christian König wrote: >> On 4/24/25 15:02, Philipp Stanner wrote: >>> In nouveau_fence_done(), a fence is checked for being signaled by >>> manually evaluating the base fence's bits. This can be done in a >>> canonical manner through dma_fence_is_signaled(). >>> >>> Replace the bit-check with dma_fence_is_signaled(). >>> >>> Signed-off-by: Philipp Stanner <phasta(a)kernel.org> >> >> >> I think the bit check was used here as fast path optimization because >> we later call dma_fence_is_signaled() anyway. > > That fast path optimization effectively saves one JMP instruction to > the function. What I meant was that we might completely drop that optimization. It looks like overkill and potentially hides bugs. Regards, Christian. > > I'm increasingly of the opinion that we shall work towards all DRM > users only ever using infrastructure through officially documented API > functions, without touching internal data structures. > >> Feel free to add my acked-by, but honestly what nouveau does here >> looks rather suspicious to me. > > :) > > > P. > >> >> Regards, >> Christian. >> >>> --- >>> drivers/gpu/drm/nouveau/nouveau_fence.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c >>> b/drivers/gpu/drm/nouveau/nouveau_fence.c >>> index fb9811938c82..d5654e26d5bc 100644 >>> --- a/drivers/gpu/drm/nouveau/nouveau_fence.c >>> +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c >>> @@ -253,7 +253,7 @@ nouveau_fence_done(struct nouveau_fence *fence) >>> struct nouveau_channel *chan; >>> unsigned long flags; >>> >>> - if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence- >>>> base.flags)) >>> + if (dma_fence_is_signaled(&fence->base)) >>> return true; >>> >>> spin_lock_irqsave(&fctx->lock, flags); >> >

4 months

[PATCH bpf-next v3 0/5] Replace CONFIG_DMABUF_SYSFS_STATS with BPF

by T.J. Mercier

Until CONFIG_DMABUF_SYSFS_STATS was added [1] it was only possible to perform per-buffer accounting with debugfs which is not suitable for production environments. Eventually we discovered the overhead with per-buffer sysfs file creation/removal was significantly impacting allocation and free times, and exacerbated kernfs lock contention. [2] dma_buf_stats_setup() is responsible for 39% of single-page buffer creation duration, or 74% of single-page dma_buf_export() duration when stressing dmabuf allocations and frees. I prototyped a change from per-buffer to per-exporter statistics with a RCU protected list of exporter allocations that accommodates most (but not all) of our use-cases and avoids almost all of the sysfs overhead. While that adds less overhead than per-buffer sysfs, and less even than the maintenance of the dmabuf debugfs_list, it's still *additional* overhead on top of the debugfs_list and doesn't give us per-buffer info. This series uses the existing dmabuf debugfs_list to implement a BPF dmabuf iterator, which adds no overhead to buffer allocation/free and provides per-buffer info. The list has been moved outside of CONFIG_DEBUG_FS scope so that it is always populated. The BPF program loaded by userspace that extracts per-buffer information gets to define its own interface which avoids the lack of ABI stability with debugfs. This will allow us to replace our use of CONFIG_DMABUF_SYSFS_STATS, and the plan is to remove it from the kernel after the next longterm stable release. [1] https://lore.kernel.org/linux-media/20201210044400.1080308-1-hridya@google.… [2] https://lore.kernel.org/all/20220516171315.2400578-1-tjmercier@google.com v1: https://lore.kernel.org/all/20250414225227.3642618-1-tjmercier@google.com v1 -> v2: Make the DMA buffer list independent of CONFIG_DEBUG_FS per Christian König Add CONFIG_DMA_SHARED_BUFFER check to kernel/bpf/Makefile per kernel test robot Use BTF_ID_LIST_SINGLE instead of BTF_ID_LIST_GLOBAL_SINGLE per Song Liu Fixup comment style, mixing code/declarations, and use ASSERT_OK_FD in selftest per Song Liu Add BPF_ITER_RESCHED feature to bpf_dmabuf_reg_info per Alexei Starovoitov Add open-coded iterator and selftest per Alexei Starovoitov Add a second test buffer from the system dmabuf heap to selftests Use the BPF program we'll use in production for selftest per Alexei Starovoitov https://r.android.com/c/platform/system/bpfprogs/+/3616123/2/dmabufIter.c https://r.android.com/c/platform/system/memory/libmeminfo/+/3614259/1/libdm… v2: https://lore.kernel.org/all/20250504224149.1033867-1-tjmercier@google.com v2 -> v3: Rebase onto bpf-next/master Move get_next_dmabuf() into drivers/dma-buf/dma-buf.c, along with the new get_first_dmabuf(). This avoids having to expose the dmabuf list and mutex to the rest of the kernel, and keeps the dmabuf mutex operations near each other in the same file. (Christian König) Add Christian's RB to dma-buf: Rename debugfs symbols Drop RFC: dma-buf: Remove DMA-BUF statistics T.J. Mercier (5): dma-buf: Rename debugfs symbols bpf: Add dmabuf iterator bpf: Add open coded dmabuf iterator selftests/bpf: Add test for dmabuf_iter selftests/bpf: Add test for open coded dmabuf_iter drivers/dma-buf/dma-buf.c | 94 +++++-- include/linux/dma-buf.h | 5 +- kernel/bpf/Makefile | 3 + kernel/bpf/dmabuf_iter.c | 149 ++++++++++ kernel/bpf/helpers.c | 5 + .../testing/selftests/bpf/bpf_experimental.h | 5 + tools/testing/selftests/bpf/config | 3 + .../selftests/bpf/prog_tests/dmabuf_iter.c | 258 ++++++++++++++++++ .../testing/selftests/bpf/progs/dmabuf_iter.c | 91 ++++++ 9 files changed, 591 insertions(+), 22 deletions(-) create mode 100644 kernel/bpf/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/progs/dmabuf_iter.c base-commit: 43745d11bfd9683abdf08ad7a5cc403d6a9ffd15 -- 2.49.0.1045.g170613ef41-goog

4 months

Re: [PATCH bpf-next v3 2/5] bpf: Add dmabuf iterator

by T.J. Mercier

On Wed, May 7, 2025 at 7:14 AM Alexei Starovoitov <alexei.starovoitov(a)gmail.com> wrote: > > On Tue, May 6, 2025 at 5:10 PM T.J. Mercier <tjmercier(a)google.com> wrote: > > > > +/** > > + * get_first_dmabuf - begin iteration through global list of DMA-bufs > > + * > > + * Returns the first buffer in the global list of DMA-bufs that's not in the > > + * process of being destroyed. Increments that buffer's reference count to > > + * prevent buffer destruction. Callers must release the reference, either by > > + * continuing iteration with get_next_dmabuf(), or with dma_buf_put(). > > + * > > + * Returns NULL If no active buffers are present. > > + */ > > kdoc wants to see 'Return:'. > > See errors in BPF CI. > > And patch 5 shouldn't be using /** for plain comments. Thanks, I found the CI errors, fixed, and verified with scripts/kernel-doc. I didn't receive emails about them though, not sure if I should have. > pw-bot: cr

4 months, 1 week

[PATCH v8 00/14] TEE subsystem for protected dma-buf allocations

by Jens Wiklander

Hi, This patch set allocates the protected DMA-bufs from a DMA-heap instantiated from the TEE subsystem. The TEE subsystem handles the DMA-buf allocations since it is the TEE (OP-TEE, AMD-TEE, TS-TEE, or perhaps a future QTEE) which sets up the protection for the memory used for the DMA-bufs. The DMA-heap uses a protected memory pool provided by the backend TEE driver, allowing it to choose how to allocate the protected physical memory. The allocated DMA-bufs must be imported with a new TEE_IOC_SHM_REGISTER_FD before they can be passed as arguments when requesting services from the secure world. Three use-cases (Secure Video Playback, Trusted UI, and Secure Video Recording) has been identified so far to serve as examples of what can be expected. The use-cases has predefined DMA-heap names, "protected,secure-video", "protected,trusted-ui", and "protected,secure-video-record". The backend driver registers protected memory pools for the use-cases it supports. Each use-case has it's own protected memory pool since different use-cases requires isolation from different parts of the system. A protected memory pool can be based on a static carveout instantiated while probing the TEE backend driver, or dynamically allocated from CMA and made protected as needed by the TEE. This can be tested on a RockPi 4B+ with the following steps: repo init -u https://github.com/jenswi-linaro/manifest.git -m rockpi4.xml \ -b prototype/sdp-v8 repo sync -j8 cd build make toolchains -j$(nproc) make all -j$(nproc) # Copy ../out/rockpi4.img to an SD card and boot the RockPi from that # Connect a monitor to the RockPi # login and at the prompt: gst-launch-1.0 videotestsrc ! \ aesenc key=1f9423681beb9a79215820f6bda73d0f \ iv=e9aa8e834d8d70b7e0d254ff670dd718 serialize-iv=true ! \ aesdec key=1f9423681beb9a79215820f6bda73d0f ! \ kmssink The aesdec module has been hacked to use an OP-TEE TA to decrypt the stream into protected DMA-bufs which are consumed by the kmssink. The primitive QEMU tests from previous patch set can be tested on RockPi in the same way with: xtest --sdp-basic The primitive test are tested on QEMU with the following steps: repo init -u https://github.com/jenswi-linaro/manifest.git -m qemu_v8.xml \ -b prototype/sdp-v8 repo sync -j8 cd build make toolchains -j$(nproc) make SPMC_AT_EL=1 all -j$(nproc) make SPMC_AT_EL=1 run-only # login and at the prompt: xtest --sdp-basic The SPMC_AT_EL=1 parameter configures the build with FF-A and an SPMC at S-EL1 inside OP-TEE. The parameter can be changed into SPMC_AT_EL=n to test without FF-A using the original SMC ABI instead. Please remember to do %rm -rf ../trusted-firmware-a/build/qemu for TF-A to be rebuilt properly using the new configuration. https://optee.readthedocs.io/en/latest/building/prerequisites.html list dependencies needed to build the above. The tests are pretty basic, mostly checking that a Trusted Application in the secure world can access and manipulate the memory. There are also some negative tests for out of bounds buffers etc. Thanks, Jens Changes since V7: * Adding "dma-buf: dma-heap: export declared functions", "cma: export cma_alloc() and cma_release()", and "dma-contiguous: export dma_contiguous_default_area" to export the symbols needed to keep the TEE subsystem as a load module. * Removing CONFIG_TEE_DMABUF_HEAP and CONFIG_TEE_CMA since they aren't needed any longer. * Addressing review comments in "optee: sync secure world ABI headers" * Better align protected memory pool initialization between the smc-abi and ffa-abi parts of the optee driver. Changes since V6: * Restricted memory is now known as protected memory since to use the same term as https://docs.vulkan.org/guide/latest/protected.html. Update all patches to consistently use protected memory. * In "tee: implement protected DMA-heap" add the hidden config option TEE_DMABUF_HEAP to tell if the DMABUF_HEAPS functions are available for the TEE subsystem * Adding "tee: refactor params_from_user()", broken out from the patch "tee: new ioctl to a register tee_shm from a dmabuf file descriptor" * For "tee: new ioctl to a register tee_shm from a dmabuf file descriptor": - Update commit message to mention protected memory - Remove and open code tee_shm_get_parent_shm() in param_from_user_memref() * In "tee: add tee_shm_alloc_cma_phys_mem" add the hidden config option TEE_CMA to tell if the CMA functions are available for the TEE subsystem * For "tee: tee_device_alloc(): copy dma_mask from parent device" and "optee: pass parent device to tee_device_alloc", added Reviewed-by: Sumit Garg <sumit.garg(a)kernel.org> Changes since V5: * Removing "tee: add restricted memory allocation" and "tee: add TEE_IOC_RSTMEM_FD_INFO" * Adding "tee: implement restricted DMA-heap", "tee: new ioctl to a register tee_shm from a dmabuf file descriptor", "tee: add tee_shm_alloc_cma_phys_mem()", "optee: pass parent device to tee_device_alloc()", and "tee: tee_device_alloc(): copy dma_mask from parent device" * The two TEE driver OPs "rstmem_alloc()" and "rstmem_free()" are replaced with a struct tee_rstmem_pool abstraction. * Replaced the the TEE_IOC_RSTMEM_ALLOC user space API with the DMA-heap API Changes since V4: * Adding the patch "tee: add TEE_IOC_RSTMEM_FD_INFO" needed by the GStreamer demo * Removing the dummy CPU access and mmap functions from the dma_buf_ops * Fixing a compile error in "optee: FF-A: dynamic restricted memory allocation" reported by kernel test robot <lkp(a)intel.com> Changes since V3: * Make the use_case and flags field in struct tee_shm u32's instead of u16's * Add more description for TEE_IOC_RSTMEM_ALLOC in the header file * Import namespace DMA_BUF in module tee, reported by lkp(a)intel.com * Added a note in the commit message for "optee: account for direction while converting parameters" why it's needed * Factor out dynamic restricted memory allocation from "optee: support restricted memory allocation" into two new commits "optee: FF-A: dynamic restricted memory allocation" and "optee: smc abi: dynamic restricted memory allocation" * Guard CMA usage with #ifdef CONFIG_CMA, effectively disabling dynamic restricted memory allocate if CMA isn't configured Changes since the V2 RFC: * Based on v6.12 * Replaced the flags for SVP and Trusted UID memory with a u32 field with unique id for each use case * Added dynamic allocation of restricted memory pools * Added OP-TEE ABI both with and without FF-A for dynamic restricted memory * Added support for FF-A with FFA_LEND Changes since the V1 RFC: * Based on v6.11 * Complete rewrite, replacing the restricted heap with TEE_IOC_RSTMEM_ALLOC Changes since Olivier's post [2]: * Based on Yong Wu's post [1] where much of dma-buf handling is done in the generic restricted heap * Simplifications and cleanup * New commit message for "dma-buf: heaps: add Linaro restricted dmabuf heap support" * Replaced the word "secure" with "restricted" where applicable Etienne Carriere (1): tee: new ioctl to a register tee_shm from a dmabuf file descriptor Jens Wiklander (13): tee: tee_device_alloc(): copy dma_mask from parent device optee: pass parent device to tee_device_alloc() optee: account for direction while converting parameters optee: sync secure world ABI headers dma-buf: dma-heap: export declared functions tee: implement protected DMA-heap tee: refactor params_from_user() cma: export cma_alloc() and cma_release() dma-contiguous: export dma_contiguous_default_area tee: add tee_shm_alloc_cma_phys_mem() optee: support protected memory allocation optee: FF-A: dynamic protected memory allocation optee: smc abi: dynamic protected memory allocation drivers/dma-buf/dma-heap.c | 3 + drivers/tee/Makefile | 1 + drivers/tee/optee/Makefile | 1 + drivers/tee/optee/call.c | 10 +- drivers/tee/optee/core.c | 1 + drivers/tee/optee/ffa_abi.c | 198 ++++++++++++- drivers/tee/optee/optee_ffa.h | 27 +- drivers/tee/optee/optee_msg.h | 83 +++++- drivers/tee/optee/optee_private.h | 55 +++- drivers/tee/optee/optee_smc.h | 69 ++++- drivers/tee/optee/protmem.c | 330 +++++++++++++++++++++ drivers/tee/optee/rpc.c | 31 +- drivers/tee/optee/smc_abi.c | 191 ++++++++++-- drivers/tee/tee_core.c | 157 +++++++--- drivers/tee/tee_heap.c | 470 ++++++++++++++++++++++++++++++ drivers/tee/tee_private.h | 16 + drivers/tee/tee_shm.c | 164 ++++++++++- include/linux/tee_core.h | 70 +++++ include/linux/tee_drv.h | 10 + include/uapi/linux/tee.h | 31 ++ kernel/dma/contiguous.c | 1 + mm/cma.c | 2 + 22 files changed, 1789 insertions(+), 132 deletions(-) create mode 100644 drivers/tee/optee/protmem.c create mode 100644 drivers/tee/tee_heap.c base-commit: b4432656b36e5cc1d50a1f2dc15357543add530e -- 2.43.0

4 months, 1 week

[PATCH v2 0/3] media: fix incorrect use of dma_sync_sg_*() calls

by Marek Szyprowski

Dear All, This patchset fixes the incorrect use of dma_sync_sg_*() calls in media and related drivers. They are replaced with much safer dma_sync_sgtable_*() variants, which take care of passing the proper number of elements for the sync operation. Best regards Marek Szyprowski, PhD Samsung R&D Institute Poland Change log: -v2: fixes typos and added cc: stable Patch summary: Marek Szyprowski (3): media: videobuf2: use sgtable-based scatterlist wrappers udmabuf: use sgtable-based scatterlist wrappers media: omap3isp: use sgtable-based scatterlist wrappers drivers/dma-buf/udmabuf.c | 5 ++--- drivers/media/common/videobuf2/videobuf2-dma-sg.c | 4 ++-- drivers/media/platform/ti/omap3isp/ispccdc.c | 8 ++++---- drivers/media/platform/ti/omap3isp/ispstat.c | 6 ++---- 4 files changed, 10 insertions(+), 13 deletions(-) -- 2.34.1

4 months, 1 week

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