As part of the experimental branch of the Linux kernel, within which the 5.4 release is being formed, , warning about the imminent end of support for 32-bit guests running in paravirtualization mode running the Xen hypervisor. Users of such systems are advised to switch to using 64-bit kernels in guest environments or use full (HVM) or combined (PVH) virtualization modes instead of paravirtualization (PV) to run environments.
PV mode as obsolete and replaced by PVH, in which paravirtualization (PV) elements are limited to I / O, interrupt handling, organizing loading and interacting with equipment, and full virtualization is used to limit privileged instructions, isolate system calls and virtualize memory page tables (HVM). The lack of protection against the vulnerability is also noted as an argument against PV mode support for 32-bit guests. .
Source: opennet.ru