Xen Project 4.15 Feature List
Arm now allows running device models in dom0 (tech preview), allowing arbitrary devices to be emulated for Arm guests. Arm also now has SMMUv3 support (also tech preview), which will improve security and reliability of device pass-through on Arm systems.
Xen can now export Intel Processor Trace (IPT) data from guests to tools in dom0, enabling tools like https://github.com/intel/kernel-fuzzer-for-xen-project or https://github.com/CERT-Polska/drakvuf-sandbox
Xen now supports Viridian enlightenments for guests with more than 64 vcpus.
“PV Shim” mode, for supporting legacy PV guests on HVM-only systems, continues to be improved; its size was reduced by further factoring out HVM-specific code. This will also help reduce the size and security of any PV-only build of the hypervisor.
Developed IOREQ server in Xen on Arm for further enablement of VirtIO protocols as a generic and standardized solution for I/O virtualization. Ability to expose a VirtIO block device to a Xen on Arm guest. Reference implementation of VirtIO block device for Xen on Arm (collaboration between Arm, EPAM and Linaro’s project STRATOS)
Features and improvements
Arm Renesas IPMMU-VMSA support upgraded to Supported, not security supported (was Tech Preview in 4.14).
Switched x86 MSR accesses to deny by default policy.
Named PCI devices for xl/libxl and improved documentation for xl PCI configuration format.
Support for zstd-compressed dom0 (x86) and domU kernels.
Reduce ACPI verbosity by default.
ucode=allow-same option to test late microcode loading path.
Library improvements from NetBSD ports upstreamed.
x86: Allow domains to use AVX-VNNI instructions.
XEN_SCRIPT_DIR configuration option to specify location for Xen scripts, rather than hard-coding
xennet: Documented a way for the backend (or toolstack) to specify MTU to the frontend.
Some additional affordances in various xl subcommands.
Added workarounds for the following ARM errata: Cortex A53 #843419, Cortex A55 #1530923, Cortex A72 #853709, Cortex A73 #858921, Cortex A76 #1286807, Neoverse-N1 #1165522.
On detecting a host crash, some debug key handlers can automatically triggered to aid in debugging.
Increase the maximum number of guests which can share a single IRQ from 7 to 16, and make this configurable with
CI loop (gitlab CI)
Add Alpine Linux, Ubuntu Focal targets; drop CentOS 6.
Add qemu-based dom0 / domU test for ARM.
Add dom0less aarch64 smoke test.
Progress on MISRA-C rules tailored for Xen in collaboration with Zephyr. MISRA-C is a set of coding guidelines for the language for safety. The SIG now has a shortlist of MISRA-C rules that apply to our project and we are currently evaluating static analyzers for each of them.
Development of host and guest virtual memory management code, one of the key components necessary for supporting guest virtualization
Development of the internal architecture-specific code to conform to Xen common APIs