Support for 32-bit Xen guest systems in paravirtualization mode is ending in the Linux kernel.

The experimental branch of the Linux kernel, which is developing release 5.4, optimizations have been made changes, warns about the imminent end of support for 32-bit guest systems running in paravirtualization mode under the Xen hypervisor. Users of such systems are advised to switch to using 64-bit kernels in guest environments or to use full virtualization (HVM) or hybrid virtualization (PVH) modes instead of paravirtualization (PV).

PV mode is considering has been considered obsolete and has been replaced by PVH, in which elements of paravirtualization (PV) are limited to input/output operations, interrupt handling, boot organization, and hardware interaction, while full virtualization (HVM) is used to limit privileged instructions, isolate system calls, and virtualize memory page tables. As an argument against supporting PV mode for 32-bit guest systems, the lack of protection against vulnerabilities is also noted. Meltdown.

Source: opennet.ru