[Issue]: Memory access fault by GPU - hipMemcpy Host-to-Device cause on gfx1150 APU

[almanar]

Problem Description

hipMemcpy Host-to-Device triggers WALKER_ERROR=1/MAPPING_ERROR=1 on gfx1150 APU — regression in kernel 6.17 (works on 6.14)

Note

After wasting 3 days debugging and a lot tokens I finally think the problem was pin pointed.
Sharing outcome to help improve rocm ecosystem. :-)
Description generated from the co-debugging sessions.

Problem Description

On an AMD Ryzen AI 9 HX PRO 370 (Strix Halo APU, Radeon 890M gfx1150), every
hipMemcpy(HostToDevice) immediately triggers a GPU memory access fault with
WALKER_ERROR: 0x1 and MAPPING_ERROR: 0x1 on kernel 6.17.0-1017-oem and
6.17.0-20-generic. The fault does not occur on kernel 6.14.0-1018-oem.

This is an APU (UMA) system — the GPU has no discrete VRAM; all memory is shared
LPDDR5. The regression is 100% reproducible on every hipMemcpy call with no
workload required.

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System Information

Field	Value
OS	Ubuntu 24.04 LTS
CPU	AMD Ryzen AI 9 HX PRO 370 w/ Radeon 890M (Strix Halo, Zen 5, 24 cores)
GPU	AMD Radeon 890M, gfx1150 (APU / UMA, no discrete VRAM)
VRAM	16384 MiB (BIOS UMA, shared system memory)
System RAM	64 GiB DDR5
ROCm	7.1.1 (Docker: rocm/dev-ubuntu-24.04:7.1.1-complete)
Working kernel	6.14.0-1018-oem (6.14.0-1018.18)
Broken kernels	6.17.0-1017-oem (6.17.0-1017.17), 6.17.0-20-generic (6.17.0-20.20~24.04.1)

KFD Node Properties (on affected 6.17 kernel)

capability      0x2903a280
HMM_BASED       0
XNACK           0
SDMA_QUEUE      0
PCIE_ATOMICS    1
WAVEFRONT_32    1
WAVEFRONT_64    1

rocminfo (GPU agent)

Name:                    gfx1150
Marketing Name:          AMD Radeon 890M
Vendor Name:             AMD
Max Clock Freq. (MHz):   2900
Compute Unit:            16
Memory Properties:       APU
XNACK enabled:           NO
ISA:                     amdgcn-amd-amdhsa--gfx1150

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What Was Tested (All Failed on 6.17)

All of the following were tried on 6.17.0-1017-oem and 6.17.0-20-generic
with no improvement:

Attempt	Result
amdgpu.noretry=0 / noretry=1 kernel param	Still faults
amdgpu.gttsize=32768 (expand GTT)	Still faults
iommu=pt kernel param	Still faults (no IOMMU/IVRS table present on this board)
amdgpu.vm_update_mode=3	Still faults
HSA_XNACK=1 env var	Still faults
HSA_ENABLE_SDMA=0 / =1	Still faults
hipHostMalloc with pinned source buffer	Still faults
mmap with MAP_LOCKED	Still faults
Docker --privileged flag	Still faults
BIOS UMA VRAM size changes (32 GiB → 512 MiB → 16 GiB → Auto)	Still faults
ROCm 7.12 native install (amdrocm-core-sdk-gfx1150)	Still faults
hipMallocManaged (SVM) read/write	Works — GPU accessible via SVM

The fact that hipMallocManaged works confirms the GPU is functional and
accessible; only the device memory copy paths (hipMemcpy, hipMalloc + copy)
are broken. This points specifically to KFD GPU VM page table management for
regular host pages.

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What Solved It

Booting into 6.14.0-1018-oem (the AMD-recommended OEM kernel for
gfx1150 ROCm workloads) fixes the issue entirely. All hipMemcpy calls succeed
immediately with no other changes.

Benchmark results after fix (llama.cpp ROCm, Llama-3.2-3B Q4_K_M):

| model                  | backend | ngl |    test |              t/s |
| ---------------------- | ------- | --: | ------: | ---------------: |
| llama 3B Q4_K - Medium | ROCm    | 999 |   pp256 |   870.75 ± 0.39  |
| llama 3B Q4_K - Medium | ROCm    | 999 |   tg128 |    31.02 ± 0.12  |

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Additional Information

• Vulkan (via RADV) works correctly on all kernels including 6.17 — this is
  strictly a KFD/ROCm issue.
• Ollama v0.21.0 (Vulkan backend) is unaffected throughout.
• No IOMMU is active on this board (dmesg shows no IVRS table); IOMMU-related
  parameters have no effect.
• The issue is fully reproducible in a clean Docker container, ruling out
  native ROCm install state.

Operating System

Ubuntu 24.04 LTS

CPU

AMD Ryzen AI 9 HX PRO 370 w/ Radeon 890M (Strix Halo, Zen 5, 24 cores)

GPU

AMD Radeon 890M, gfx1150 (APU / UMA, no discrete VRAM)

ROCm Version

7.1.1 (Docker: rocm/dev-ubuntu-24.04:7.1.1-complete)

ROCm Component

No response

Steps to Reproduce

Minimal Reproducer

The following test was run inside the official ROCm Docker container to isolate
from any native install differences:

docker run --rm \
  --device=/dev/kfd --device=/dev/dri \
  --security-opt seccomp=unconfined \
  --group-add video \
  --ipc=host --shm-size=16g \
  rocm/dev-ubuntu-24.04:7.1.1-complete bash -lc '
cat > /tmp/test.cpp << "EOF"
#include <hip/hip_runtime.h>
#include <stdio.h>
#include <stdlib.h>

#define CHECK(cmd) { \
    hipError_t e = (cmd); \
    if (e != hipSuccess) { \
        printf("FAIL %s: %s\n", #cmd, hipGetErrorString(e)); \
        exit(1); \
    } \
}

int main() {
    float *h = (float*)malloc(4096);
    h[0] = 42.0f;
    float *d;
    CHECK(hipMalloc(&d, 4096));
    CHECK(hipMemcpy(d, h, 4096, hipMemcpyHostToDevice));   // <-- faults here
    CHECK(hipMemcpy(h, d, 4096, hipMemcpyDeviceToHost));
    printf("PASS result=%g\n", h[0]);
    return 0;
}
EOF
hipcc /tmp/test.cpp -o /tmp/test && /tmp/test'

Result on 6.17.0-1017-oem / 6.17.0-20-generic (FAIL)

FAIL hipMemcpy: Memory access fault by GPU node-1 (Agent handle: ...) on address 0x...

Corresponding dmesg output:

amdgpu 0000:c4:00.0: amdgpu: [gfxhub] page fault (src_id:0 ring:0 vmid:... pasid:...)
amdgpu 0000:c4:00.0: amdgpu:  Process test pid ... thread test pid ...
amdgpu 0000:c4:00.0: amdgpu:   in page starting at address 0x... from client ...
amdgpu 0000:c4:00.0: amdgpu: GCVM_L2_PROTECTION_FAULT_STATUS: ...
amdgpu 0000:c4:00.0: amdgpu:          WALKER_ERROR: 0x1
amdgpu 0000:c4:00.0: amdgpu:          MAPPING_ERROR: 0x1
amdgpu 0000:c4:00.0: amdgpu:          PERMISSION_FAULTS: 0x0

WALKER_ERROR=1 means the GPU page table walker itself failed — the GPU cannot
walk the page tables for the host address at all, not a permission issue.

Result on 6.14.0-1018-oem (PASS)

PASS result=42

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(Optional for Linux users) Output of /opt/rocm/bin/rocminfo --support

No response

Additional Information

No response