* fix: prevent ROCm torch from installing on NVIDIA Linux hosts
NVIDIA's open kernel module (driver 560+) registers GPU topology nodes in
the KFD sysfs hierarchy with non-zero gpu_id values. The _has_amd_rocm_gpu
(install.sh) and _has_rocm_gpu (install_python_stack.py) sysfs fallbacks
previously treated any non-zero gpu_id as proof of an AMD GPU, so an
NVIDIA-only host with the open kernel driver was misrouted to the ROCm
install path, replacing the correctly-installed CUDA torch with ROCm wheels.
Fixes:
1. install.sh _has_amd_rocm_gpu sysfs fallback: require vendor_id 4098
(AMD 0x1002) in the KFD node properties file before declaring an AMD
GPU present. NVIDIA KFD nodes carry vendor_id 4318 (0x10DE) and are
now skipped.
2. install_python_stack.py _has_rocm_gpu sysfs fallback: same vendor_id
guard. Also preserves the existing fallback for older kernels that
don't ship a properties file (trusts gpu_id alone there).
3. install.sh now exports UNSLOTH_TORCH_BACKEND ("cuda"/"rocm"/"cpu")
immediately after get_torch_index_url() resolves the wheel family.
install_python_stack.py reads this as _TORCH_BACKEND and short-circuits
_ensure_rocm_torch() entirely on cuda/cpu hosts, providing a second
layer of defense that is independent of subprocess GPU detection.
Tests: 9 new cases in TestHasRocmGpuKfdVendorGuard,
TestEnsureRocmTorch, and TestInstallShStructure cover all three changes.
Full test_rocm_support.py suite: 289 passed, 2 skipped, 0 failed.
Closes#6172
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* fix: show actual torch backend in progress step labels
The 'ROCm torch check' and 'ROCm torch (final)' step labels were
hardcoded regardless of whether the installer was targeting CUDA, ROCm,
or CPU. On NVIDIA hosts they showed 'ROCm' even though no ROCm wheels
were being installed, which was misleading.
Add _torch_step_label(suffix) which reads UNSLOTH_TORCH_BACKEND (set by
install.sh) and formats the label as e.g. 'torch check (cuda)' or
'torch final (rocm)'. Falls back to live GPU detection for standalone
studio update runs that bypass install.sh.
* fix: make KFD sysfs vendor check conservative -- skip if no properties file
The previous implementation fell through to `return True` when the KFD
node's properties file was missing (OSError), intending to support older
kernels. But NVIDIA open driver KFD nodes can also lack a properties file
on some kernel versions, so the fallback still produced a false positive.
Change the `except OSError: pass` to `continue` so any node without a
readable properties file is skipped rather than trusted. KFD properties
files exist on every kernel version that actually exposes /sys/class/kfd,
so this does not regress real AMD GPU detection -- if the directory exists
at all, properties files will be present for genuine GPU nodes.
* fix: bulletproof NVIDIA vs AMD GPU detection
Four changes that together ensure ROCm torch can never be installed on an
NVIDIA host regardless of which detection path fires:
1. _has_rocm_gpu() (Python): NVIDIA guard at the top -- returns False
immediately when _has_usable_nvidia_gpu() is True, blocking rocminfo,
amd-smi, and KFD sysfs from producing a false positive even when ROCm
tools are co-installed alongside the NVIDIA driver.
2. _has_amd_rocm_gpu() (install.sh): same NVIDIA guard -- calls
_has_usable_nvidia_gpu first and returns 1 if it succeeds.
3. _has_usable_nvidia_gpu() (Python): adds /proc/driver/nvidia/gpus/
sysfs fallback. The NVIDIA driver populates this directory on Linux
regardless of nvidia-smi state, so a subprocess PATH gap, timeout, or
driver initialisation race can no longer silence NVIDIA detection.
4. _has_usable_nvidia_gpu() (install.sh): same /proc/driver/nvidia/gpus
fallback, tried after nvidia-smi -L rather than instead of it.
Together: NVIDIA wins at every decision point. If nvidia-smi works, it
confirms NVIDIA. If it fails, /proc/driver/nvidia confirms NVIDIA. If
somehow both fail, _has_rocm_gpu still checks NVIDIA first before any AMD
path runs.
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* fix: two KFD/proc-only corner cases from Codex review
1. KFD awk state not reset per node file (Ryzen+NVIDIA false positive):
The awk glob processes all topology node properties files in one pass.
Without FNR==1 reset, a Ryzen+NVIDIA host where an AMD CPU-agent node
sets amd=1 (vendor_id 4098, gpu_id 0) can combine with a later NVIDIA
node setting gpu=1 (gpu_id > 0), triggering found=1 before vendor_id
4318 is seen. Added FNR==1{ gpu=0; amd=0 } to reset per file.
2. proc-only NVIDIA not reaching CUDA wheel selection:
_has_usable_nvidia_gpu returning true via /proc/driver/nvidia fallback
left _smi empty, so get_torch_index_url entered the AMD/CPU branch and
selected CPU wheels despite NVIDIA being confirmed. Introduced
_nvidia_detected flag (separate from _smi) so the AMD branch is skipped
whenever NVIDIA is confirmed by any path, while _cuda_ver reads from
_smi when available (with the existing cu126 fallback when _smi is absent).
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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
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