Linux 5.9 Dropping Xen 32-bit PV Guest Support

Back in Linux 5.4 Xen 32-bit PV guest support was deprecated while now for Linux 5.9 it's set to be removed entirely. Last year's deprecation comes with the 32-bit usage dwindling in general but PVH being preferred to PV, Meltdown mitigations not being present, and the code not seeing much activity. Now for Linux 5.9 that support is being gutted.

Sent in today were more Xen patches for the Linux 5.9 merge window closing this weekend. The most notable change is the clearing out of the 32-bit Xen PV guest support:

Removal of support for running as 32-bit Xen PV-guest. 32-bit PV guests are rarely used, are lacking security fixes for Meltdown, and can be easily replaced by PVH mode. Another series for doing more cleanup will follow soon (removal of 32-bit-only pvops functionality).

Long overdue but great to see it finally removed. Similarly, over in the ARM 32-bit world, earlier this year brought retiring of 32-bit ARM KVM support.