GPU plugin: skip announcing parent GPU if MIG-enabled (fix #719)

[jgehrcke]

Fixes #719. Unskips the corresponding regression test.

From CI:

ok 13 static MIG: mutual exclusivity with physical GPU in 20508ms

(logs)

[klueska]

Suggested change

	if gpuInfo.migEnabled {
	if len(migdevs) == 0 {
	// Likely uninintentionally stranded capacity (misconfiguration).
	klog.Warningf("Physical GPU %s has MIG mode enabled but no configured MIG devices", gpuInfo.CanonicalName())
	}
	for _, mdev := range migdevs {
	klog.Infof("Adding MIG device %s to allocatable devices (parent: %s)", mdev.CanonicalName(), gpuInfo.CanonicalName())
	devices[mdev.CanonicalName()] = mdev
	}
	} else {
	klog.Infof("Adding device %s to allocatable devices", gpuInfo.CanonicalName())
	devices[gpuInfo.CanonicalName()] = parentdev
	}
	if !gpuInfo.migEnabled {
	klog.Infof("Adding device %s to allocatable devices", gpuInfo.CanonicalName())
	devices[gpuInfo.CanonicalName()] = parentdev
	return nil
	}
	// Likely unintentionally stranded capacity (misconfiguration).
	if len(migdevs) == 0 {
	klog.Warningf("Physical GPU %s has MIG mode enabled but no configured MIG devices", gpuInfo.CanonicalName())
	}
	for _, mdev := range migdevs {
	klog.Infof("Adding MIG device %s to allocatable devices (parent: %s)", mdev.CanonicalName(), gpuInfo.CanonicalName())
	devices[mdev.CanonicalName()] = mdev
	}
	return nil
	}

[jgehrcke]

ack, pushed change

[elezar]

We don't need this unless the gpu does not have MIG enabled. Does it make sense to only instantate this in that return path? (not a blocker though).

[jgehrcke]

Agree!

(not doing this here; this section will change quite a bit again in upcoming patches; in this PR it's OK to just do something that gets the test to pass)

[elezar]

Why do we not check this BEFORE we start iterating mig devices?

[jgehrcke]

You mean before

l.discoverMigDevicesByGPU()

?

Yes, that can make sense. (not required towards correct behavior, though, ack?)

Again, not doing that here -- this section will change quite a bit again in upcoming patches.

[jgehrcke]

/cherry-pick release-25.8

[github-actions]

🤖 Backport PR created for release-25.8: #779 ⚠️ (has conflicts)