Linux 6.1 Xen Supports Grant-Based VirtIO For x86_64

The Xen hypervisor changes were merged this week for the Linux 6.1 kernel merge window that is wrapping up this weekend.

With the Xen changes for Linux 6.1 there are a number of fixes while one of the new feature additions this cycle is enabling grant-based VirtIO with Xen on x86/x86_64. This work is part of the solution that's been in development over the past number of months to allow restricting memory access under Xen. This work to support restricting memory access under Xen is being backed using Xen's grant table DMA mapping layer.

If the Linux 6.1+ kernel is built with CONFIG_XEN_VIRTIO_FORCE_GRANT, it will provide for Xen guests to use grant mappings for VirtIO and allows bypassing the need for the Xen back-end the right to map all of the guest memory.

More details on the Xen changes for Linux 6.1 via this pull request of the since merged new feature code.

Separately, last week saw the KVM updates submitted for Linux 6.1 to which were mostly a collection of fixes and other smaller changes.