kernel/linux.git/drivers/gpu/drm/amd/amdkfd, branch v7.0-rc7

drm/amdkfd: Fix queue preemption/eviction failures by aligning control stack size to GPU page size

2026-03-30T20:22:44+00:00

The control stack size is calculated based on the number of CUs and waves, and is then aligned to PAGE_SIZE. When the resulting control stack size is aligned to 64 KB, GPU hangs and queue preemption failures are observed while running RCCL unit tests on systems with more than two GPUs. amdgpu 0048:0f:00.0: amdgpu: Queue preemption failed for queue with doorbell_id: 80030008 amdgpu 0048:0f:00.0: amdgpu: Failed to evict process queues amdgpu 0048:0f:00.0: amdgpu: GPU reset begin!. Source: 4 amdgpu 0048:0f:00.0: amdgpu: Queue preemption failed for queue with doorbell_id: 80030008 amdgpu 0048:0f:00.0: amdgpu: Failed to evict process queues amdgpu 0048:0f:00.0: amdgpu: Failed to restore process queues This issue is observed on both 4 KB and 64 KB system page-size configurations. This patch fixes the issue by aligning the control stack size to AMDGPU_GPU_PAGE_SIZE instead of PAGE_SIZE, so the control stack size will not be 64 KB on systems with a 64 KB page size and queue preemption works correctly. Additionally, In the current code, wg_data_size is aligned to PAGE_SIZE, which can waste memory if the system page size is large. In this patch, wg_data_size is aligned to AMDGPU_GPU_PAGE_SIZE. The cwsr_size, calculated from wg_data_size and the control stack size, is aligned to PAGE_SIZE. Reviewed-by: Felix Kuehling Signed-off-by: Donet Tom Signed-off-by: Alex Deucher (cherry picked from commit a3e14436304392fbada359edd0f1d1659850c9b7)

drm/amdgpu: Change AMDGPU_VA_RESERVED_TRAP_SIZE to 64KB

2026-03-30T20:14:11+00:00

Currently, AMDGPU_VA_RESERVED_TRAP_SIZE is hardcoded to 8KB, while KFD_CWSR_TBA_TMA_SIZE is defined as 2 * PAGE_SIZE. On systems with 4K pages, both values match (8KB), so allocation and reserved space are consistent. However, on 64K page-size systems, KFD_CWSR_TBA_TMA_SIZE becomes 128KB, while the reserved trap area remains 8KB. This mismatch causes the kernel to crash when running rocminfo or rccl unit tests. Kernel attempted to read user page (2) - exploit attempt? (uid: 1001) BUG: Kernel NULL pointer dereference on read at 0x00000002 Faulting instruction address: 0xc0000000002c8a64 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries CPU: 34 UID: 1001 PID: 9379 Comm: rocminfo Tainted: G E 6.19.0-rc4-amdgpu-00320-gf23176405700 #56 VOLUNTARY Tainted: [E]=UNSIGNED_MODULE Hardware name: IBM,9105-42A POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.30 (ML1060_896) hv:phyp pSeries NIP: c0000000002c8a64 LR: c00000000125dbc8 CTR: c00000000125e730 REGS: c0000001e0957580 TRAP: 0300 Tainted: G E MSR: 8000000000009033 CR: 24008268 XER: 00000036 CFAR: c00000000125dbc4 DAR: 0000000000000002 DSISR: 40000000 IRQMASK: 1 GPR00: c00000000125d908 c0000001e0957820 c0000000016e8100 c00000013d814540 GPR04: 0000000000000002 c00000013d814550 0000000000000045 0000000000000000 GPR08: c00000013444d000 c00000013d814538 c00000013d814538 0000000084002268 GPR12: c00000000125e730 c000007e2ffd5f00 ffffffffffffffff 0000000000020000 GPR16: 0000000000000000 0000000000000002 c00000015f653000 0000000000000000 GPR20: c000000138662400 c00000013d814540 0000000000000000 c00000013d814500 GPR24: 0000000000000000 0000000000000002 c0000001e0957888 c0000001e0957878 GPR28: c00000013d814548 0000000000000000 c00000013d814540 c0000001e0957888 NIP [c0000000002c8a64] __mutex_add_waiter+0x24/0xc0 LR [c00000000125dbc8] __mutex_lock.constprop.0+0x318/0xd00 Call Trace: 0xc0000001e0957890 (unreliable) __mutex_lock.constprop.0+0x58/0xd00 amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu+0x6fc/0xb60 [amdgpu] kfd_process_alloc_gpuvm+0x54/0x1f0 [amdgpu] kfd_process_device_init_cwsr_dgpu+0xa4/0x1a0 [amdgpu] kfd_process_device_init_vm+0xd8/0x2e0 [amdgpu] kfd_ioctl_acquire_vm+0xd0/0x130 [amdgpu] kfd_ioctl+0x514/0x670 [amdgpu] sys_ioctl+0x134/0x180 system_call_exception+0x114/0x300 system_call_vectored_common+0x15c/0x2ec This patch changes AMDGPU_VA_RESERVED_TRAP_SIZE to 64 KB and KFD_CWSR_TBA_TMA_SIZE to the AMD GPU page size. This means we reserve 64 KB for the trap in the address space, but only allocate 8 KB within it. With this approach, the allocation size never exceeds the reserved area. Fixes: 34a1de0f7935 ("drm/amdkfd: Relocate TBA/TMA to opposite side of VM hole") Reviewed-by: Christian König Suggested-by: Felix Kuehling Suggested-by: Christian König Signed-off-by: Donet Tom Signed-off-by: Alex Deucher (cherry picked from commit 31b8de5e55666f26ea7ece5f412b83eab3f56dbb) Cc: stable@vger.kernel.org

drm/amd: Fix MQD and control stack alignment for non-4K

2026-03-30T20:12:27+00:00

For gfxV9, due to a hardware bug ("based on the comments in the code here [1]"), the control stack of a user-mode compute queue must be allocated immediately after the page boundary of its regular MQD buffer. To handle this, we allocate an enlarged MQD buffer where the first page is used as the MQD and the remaining pages store the control stack. Although these regions share the same BO, they require different memory types: the MQD must be UC (uncached), while the control stack must be NC (non-coherent), matching the behavior when the control stack is allocated in user space. This logic works correctly on systems where the CPU page size matches the GPU page size (4K). However, the current implementation aligns both the MQD and the control stack to the CPU PAGE_SIZE. On systems with a larger CPU page size, the entire first CPU page is marked UC—even though that page may contain multiple GPU pages. The GPU treats the second 4K GPU page inside that CPU page as part of the control stack, but it is incorrectly mapped as UC. This patch fixes the issue by aligning both the MQD and control stack sizes to the GPU page size (4K). The first 4K page is correctly marked as UC for the MQD, and the remaining GPU pages are marked NC for the control stack. This ensures proper memory type assignment on systems with larger CPU page sizes. [1]: https://elixir.bootlin.com/linux/v6.18/source/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c#L118 Acked-by: Felix Kuehling Signed-off-by: Donet Tom Signed-off-by: Alex Deucher (cherry picked from commit 998d6781410de1c4b787fdbf6c56e851ea7fa553)

drm/amdkfd: Align expected_queue_size to PAGE_SIZE

2026-03-30T20:11:29+00:00

The AQL queue size can be 4K, but the minimum buffer object (BO) allocation size is PAGE_SIZE. On systems with a page size larger than 4K, the expected queue size does not match the allocated BO size, causing queue creation to fail. Align the expected queue size to PAGE_SIZE so that it matches the allocated BO size and allows queue creation to succeed. Reviewed-by: Felix Kuehling Signed-off-by: Donet Tom Signed-off-by: Alex Deucher (cherry picked from commit b01cd158a2f5230b137396c5f8cda3fc780abbc2)

drm/amdkfd: Fix NULL pointer check order in kfd_ioctl_create_process

2026-03-24T17:54:19+00:00

In kfd_ioctl_create_process(), the pointer 'p' is used before checking if it is NULL. The code accesses p->context_id before validating 'p'. This can lead to a possible NULL pointer dereference. Move the NULL check before using 'p' so that the pointer is validated before access. Fixes the below: drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_chardev.c:3177 kfd_ioctl_create_process() warn: variable dereferenced before check 'p' (see line 3174) Fixes: cc6b66d661fd ("amdkfd: introduce new ioctl AMDKFD_IOC_CREATE_PROCESS") Cc: Zhu Lingshan Cc: Felix Kuehling Cc: Christian König Cc: Alex Deucher Cc: Dan Carpenter Signed-off-by: Srinivasan Shanmugam Reviewed-by: Christian König Signed-off-by: Alex Deucher (cherry picked from commit 19d4149b22f57094bfc4b86b742381b3ca394ead)

drm/amdkfd: Unreserve bo if queue update failed

2026-03-11T18:02:45+00:00

Error handling path should unreserve bo then return failed. Fixes: 305cd109b761 ("drm/amdkfd: Validate user queue update") Signed-off-by: Philip Yang Reviewed-by: Alex Sierra Signed-off-by: Alex Deucher (cherry picked from commit c24afed7de9ecce341825d8ab55a43a254348b33)

Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses

2026-02-22T16:26:33+00:00

Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook