emulated graphics cards or framebuffers cause GPU test failure on Linux

[jaypipes]

There's a few things going on with the GPU test when running on my new system76 monster workstation:

➜  ghw git:(fix-gpu-test) go test -v ./pkg/gpu/...
=== RUN   TestGPUWithoutNUMANodeInfo
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu0/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu1/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu10/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu11/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu2/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu3/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu4/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu5/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu6/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu7/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu8/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu9/online: no such file or directory
WARNING: failed to determine memory area for node: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/meminfo: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/class/drm/card0/device/numa_node: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu0/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu1/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu10/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu11/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu2/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu3/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu4/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu5/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu6/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu7/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu8/online: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/cpu9/online: no such file or directory
WARNING: failed to determine memory area for node: open /tmp/ghw-gpu-testing-298741871/sys/devices/system/node/node0/meminfo: no such file or directory
--- PASS: TestGPUWithoutNUMANodeInfo (0.05s)
=== RUN   TestGPU
WARNING: failed to read int from file: open /sys/devices/system/node/node0/cpu0/online: no such file or directory
WARNING: failed to read int from file: open /sys/class/drm/card0/device/numa_node: no such file or directory
WARNING: failed to read int from file: open /sys/devices/system/node/node0/cpu0/online: no such file or directory
WARNING: error parsing the pci address "simple-framebuffer.0"
    gpu_test.go:37: Expected card with address simple-framebuffer.0 to have non-nil DeviceInfo.
--- FAIL: TestGPU (0.03s)
FAIL
FAIL	github.com/jaypipes/ghw/pkg/gpu	0.083s
FAIL
➜  ghw git:(fix-gpu-test) ll /sys/class/drm
total 0
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/simple-framebuffer.0/drm/card0
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card0-Unknown-1 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/simple-framebuffer.0/drm/card0/card0-Unknown-1
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card1 -> ../../devices/pci0000:00/0000:00:02.0/drm/card1
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card1-DP-1 -> ../../devices/pci0000:00/0000:00:02.0/drm/card1/card1-DP-1
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card1-HDMI-A-1 -> ../../devices/pci0000:00/0000:00:02.0/drm/card1/card1-HDMI-A-1
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card1-HDMI-A-2 -> ../../devices/pci0000:00/0000:00:02.0/drm/card1/card1-HDMI-A-2
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card2 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card2
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card2-DP-2 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card2/card2-DP-2
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card2-DP-3 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card2/card2-DP-3
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card2-DP-4 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card2/card2-DP-4
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card2-HDMI-A-3 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card2/card2-HDMI-A-3
lrwxrwxrwx 1 root root    0 Sep 20 00:15 renderD128 -> ../../devices/pci0000:00/0000:00:02.0/drm/renderD128
lrwxrwxrwx 1 root root    0 Sep 20 00:15 renderD129 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/renderD129
-r--r--r-- 1 root root 4.0K Sep 20 00:15 version

The first issue is that the /sys/devices/system/node/nodeX/cpuX/online file does not exist in the linux-amd64-amd-ryzen-1600 ghw snapshot and therefore all those warning messages appear.

The second issue is that emulated graphics cards such as the simple framebuffer seen here:

➜  ghw git:(fix-gpu-test) ll /sys/class/drm
total 0
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/simple-framebuffer.0/drm/card0
lrwxrwxrwx 1 root root    0 Sep 20 00:15 card0-Unknown-1 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/simple-framebuffer.0/drm/card0/card0-Unknown-1

cause the pkg/gpu.Info() function to return an empty DeviceInfo for that graphics card.

[jaypipes]

After silencing some of the online state file warnings and adding a ctx.Warn() call to pkg/gpu.gpuFillPCIDevice() I see this:

➜  ghw git:(fix-gpu-test) ✗ go test -v ./pkg/gpu/...
=== RUN   TestGPUWithoutNUMANodeInfo
WARNING: failed to determine memory area for node: open /tmp/ghw-gpu-testing-3263672792/sys/devices/system/node/node0/meminfo: no such file or directory
WARNING: failed to read int from file: open /tmp/ghw-gpu-testing-3263672792/sys/class/drm/card0/device/numa_node: no such file or directory
WARNING: failed to determine memory area for node: open /tmp/ghw-gpu-testing-3263672792/sys/devices/system/node/node0/meminfo: no such file or directory
WARNING: failed to PCI device database: No pci-ids DB files found (and network fetch disabled)
--- PASS: TestGPUWithoutNUMANodeInfo (0.09s)
=== RUN   TestGPU
WARNING: failed to read int from file: open /sys/class/drm/card0/device/numa_node: no such file or directory
WARNING: error parsing the pci address "simple-framebuffer.0"

So, we need to add a static PCI database file in our testdata/ and pass the context a hard-coded path to that.