kernel/linux.git/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c, branch v6.18.21

drm/amdgpu: Skip loading SDMA_RS64 in VF

2026-03-04T12:19:54+00:00

[ Upstream commit 39c21b81112321cbe1267b02c77ecd2161ce19aa ] VFs use the PF SDMA ucode and are unable to load SDMA_RS64. Signed-off-by: YuBiao Wang Signed-off-by: Victor Skvortsov Reviewed-by: Gavin Wan Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: Fix NULL pointer dereference in VRAM logic for APU devices

2025-10-13T18:14:15+00:00

Previously, APU platforms (and other scenarios with uninitialized VRAM managers) triggered a NULL pointer dereference in `ttm_resource_manager_usage()`. The root cause is not that the `struct ttm_resource_manager *man` pointer itself is NULL, but that `man->bdev` (the backing device pointer within the manager) remains uninitialized (NULL) on APUs—since APUs lack dedicated VRAM and do not fully set up VRAM manager structures. When `ttm_resource_manager_usage()` attempts to acquire `man->bdev->lru_lock`, it dereferences the NULL `man->bdev`, leading to a kernel OOPS. 1. **amdgpu_cs.c**: Extend the existing bandwidth control check in `amdgpu_cs_get_threshold_for_moves()` to include a check for `ttm_resource_manager_used()`. If the manager is not used (uninitialized `bdev`), return 0 for migration thresholds immediately—skipping VRAM-specific logic that would trigger the NULL dereference. 2. **amdgpu_kms.c**: Update the `AMDGPU_INFO_VRAM_USAGE` ioctl and memory info reporting to use a conditional: if the manager is used, return the real VRAM usage; otherwise, return 0. This avoids accessing `man->bdev` when it is NULL. 3. **amdgpu_virt.c**: Modify the vf2pf (virtual function to physical function) data write path. Use `ttm_resource_manager_used()` to check validity: if the manager is usable, calculate `fb_usage` from VRAM usage; otherwise, set `fb_usage` to 0 (APUs have no discrete framebuffer to report). This approach is more robust than APU-specific checks because it: - Works for all scenarios where the VRAM manager is uninitialized (not just APUs), - Aligns with TTM's design by using its native helper function, - Preserves correct behavior for discrete GPUs (which have fully initialized `man->bdev` and pass the `ttm_resource_manager_used()` check). v4: use ttm_resource_manager_used(&adev->mman.vram_mgr.manager) instead of checking the adev->gmc.is_app_apu flag (Christian) Reviewed-by: Christian König Suggested-by: Lijo Lazar Signed-off-by: Jesse Zhang Signed-off-by: Alex Deucher

drm/amdgpu: Introduce VF critical region check for RAS poison injection

2025-09-18T13:43:02+00:00

The SRIOV guest send requet to host to check whether the poison injection address is in VF critical region or not via mabox. Signed-off-by: Xiang Liu Reviewed-by: Shravan Kumar Gande Signed-off-by: Alex Deucher

drm/amdgpu: Implement Runtime Bad Page query for VFs

2025-05-07T21:41:49+00:00

Host will send a notification when new bad pages are available. Uopn guest request, the first 256 bad page addresses will be placed into the PF2VF region. Guest should pause the PF2VF worker thread while the copy is in progress. Reviewed-by: Shravan Kumar Gande Signed-off-by: Victor Skvortsov Signed-off-by: Ellen Pan Signed-off-by: Alex Deucher

drm/amdgpu: Fix CPER error handling on VFs

2025-04-07T22:00:40+00:00

CPER read will loop infinitely if an error is encountered and the more bit is set. Add error checks to break upon failure. v2: added function pointer checks Suggested-by: Tony Yi Signed-off-by: Victor Skvortsov Reviewed-by: Hawking Zhang Signed-off-by: Alex Deucher

drm/amd/amdgpu: Fix MES init sequence

2025-03-14T03:16:08+00:00

When MES is been used , the set_hw_resource_1 API is required to initialize MES internal context correctly Signed-off-by: Shaoyun Liu Acked-by: Alex Deucher Reviewed-by: Srinivasan Shanmugam Signed-off-by: Alex Deucher

drm/amdgpu: Add support for CPERs on virtualization

2025-03-05T15:47:03+00:00

Add support for CPERs on VFs. VFs do not receive PMFW messages directly; as such, they need to query them from the host. To avoid hitting host event guard, CPER queries need to be rate limited. CPER queries share the same RAS telemetry buffer as error count query, so a mutex protecting the shared buffer was added as well. For readability, the amdgpu_detect_virtualization was refactored into multiple individual functions. Signed-off-by: Tony Yi Reviewed-by: Tao Zhou Reviewed-by: Hawking Zhang Signed-off-by: Alex Deucher

drm/amdgpu: Replace Mutex with Spinlock for RLCG register access to avoid Priority Inversion in SRIOV

2025-02-19T20:14:38+00:00

RLCG Register Access is a way for virtual functions to safely access GPU registers in a virtualized environment., including TLB flushes and register reads. When multiple threads or VFs try to access the same registers simultaneously, it can lead to race conditions. By using the RLCG interface, the driver can serialize access to the registers. This means that only one thread can access the registers at a time, preventing conflicts and ensuring that operations are performed correctly. Additionally, when a low-priority task holds a mutex that a high-priority task needs, ie., If a thread holding a spinlock tries to acquire a mutex, it can lead to priority inversion. register access in amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical. The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being called, which attempts to acquire the mutex. This function is invoked from amdgpu_sriov_wreg, which in turn is called from gmc_v11_0_flush_gpu_tlb. The [ BUG: Invalid wait context ] indicates that a thread is trying to acquire a mutex while it is in a context that does not allow it to sleep (like holding a spinlock). Fixes the below: [ 253.013423] ============================= [ 253.013434] [ BUG: Invalid wait context ] [ 253.013446] 6.12.0-amdstaging-drm-next-lol-050225 #14 Tainted: G U OE [ 253.013464] ----------------------------- [ 253.013475] kworker/0:1/10 is trying to lock: [ 253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.013815] other info that might help us debug this: [ 253.013827] context-{4:4} [ 253.013835] 3 locks held by kworker/0:1/10: [ 253.013847] #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680 [ 253.013877] #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680 [ 253.013905] #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu] [ 253.014154] stack backtrace: [ 253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G U OE 6.12.0-amdstaging-drm-next-lol-050225 #14 [ 253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024 [ 253.014224] Workqueue: events work_for_cpu_fn [ 253.014241] Call Trace: [ 253.014250] [ 253.014260] dump_stack_lvl+0x9b/0xf0 [ 253.014275] dump_stack+0x10/0x20 [ 253.014287] __lock_acquire+0xa47/0x2810 [ 253.014303] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.014321] lock_acquire+0xd1/0x300 [ 253.014333] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.014562] ? __lock_acquire+0xa6b/0x2810 [ 253.014578] __mutex_lock+0x85/0xe20 [ 253.014591] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.014782] ? sched_clock_noinstr+0x9/0x10 [ 253.014795] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.014808] ? local_clock_noinstr+0xe/0xc0 [ 253.014822] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.015012] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.015029] mutex_lock_nested+0x1b/0x30 [ 253.015044] ? mutex_lock_nested+0x1b/0x30 [ 253.015057] amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.015249] amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu] [ 253.015435] gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu] [ 253.015667] gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu] [ 253.015901] ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu] [ 253.016159] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.016173] ? smu_hw_init+0x18d/0x300 [amdgpu] [ 253.016403] amdgpu_device_init+0x29ad/0x36a0 [amdgpu] [ 253.016614] amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu] [ 253.017057] amdgpu_pci_probe+0x1c2/0x660 [amdgpu] [ 253.017493] local_pci_probe+0x4b/0xb0 [ 253.017746] work_for_cpu_fn+0x1a/0x30 [ 253.017995] process_one_work+0x21e/0x680 [ 253.018248] worker_thread+0x190/0x330 [ 253.018500] ? __pfx_worker_thread+0x10/0x10 [ 253.018746] kthread+0xe7/0x120 [ 253.018988] ? __pfx_kthread+0x10/0x10 [ 253.019231] ret_from_fork+0x3c/0x60 [ 253.019468] ? __pfx_kthread+0x10/0x10 [ 253.019701] ret_from_fork_asm+0x1a/0x30 [ 253.019939] v2: s/spin_trylock/spin_lock_irqsave to be safe (Christian). Fixes: e864180ee49b ("drm/amdgpu: Add lock around VF RLCG interface") Cc: lin cao Cc: Jingwen Chen Cc: Victor Skvortsov Cc: Zhigang Luo Cc: Christian König Cc: Alex Deucher Signed-off-by: Srinivasan Shanmugam Suggested-by: Alex Deucher Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amdgpu: Skip err_count sysfs creation on VF unsupported RAS blocks

2025-02-13T02:02:59+00:00

VFs are not able to query error counts for all RAS blocks. Rather than returning error for queries on these blocks, skip sysfs the creation all together. Signed-off-by: Victor Skvortsov Reviewed-by: Hawking Zhang Signed-off-by: Alex Deucher

drm/admgpu: replace kmalloc() and memcpy() with kmemdup()

2024-12-18T17:39:08+00:00

The static analyser tool gave the following advice: ./drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c:1266:7-14: WARNING opportunity for kmemdup → 1266 tmp = kmalloc(used_size, GFP_KERNEL); 1267 if (!tmp) 1268 return -ENOMEM; 1269 → 1270 memcpy(tmp, &host_telemetry->body.error_count, used_size); Replacing kmalloc() + memcpy() with kmemdump() doesn't change semantics. Original code works without fault, so this is not a bug fix but proposed improvement. Link: https://lwn.net/Articles/198928/ Fixes: 84a2947ecc85 ("drm/amdgpu: Implement virt req_ras_err_count") Cc: Alex Deucher Cc: "Christian König" Cc: Xinhui Pan Cc: David Airlie Cc: Simona Vetter Cc: Zhigang Luo Cc: Victor Skvortsov Cc: Hawking Zhang Cc: Lijo Lazar Cc: Yunxiang Li Cc: Jack Xiao Cc: Vignesh Chander Cc: Danijel Slivka Cc: amd-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Lijo Lazar Signed-off-by: Mirsad Todorovac Signed-off-by: Alex Deucher