On Wed, 27 Aug 2025 17:52:41 +0000, Shivank Garg wrote:
This series introduces NUMA-aware memory placement support for KVM guests with guest_memfd memory backends. It builds upon Fuad Tabba's work (V17) that enabled host-mapping for guest_memfd memory [1] and can be applied directly applied on KVM tree [2] (branch kvm-next, base commit: a6ad5413, Merge branch 'guest-memfd-mmap' into HEAD)
== Background == KVM's guest-memfd memory backend currently lacks support for NUMA policy enforcement, causing guest memory allocations to be distributed across host nodes according to kernel's default behavior, irrespective of any policy specified by the VMM. This limitation arises because conventional userspace NUMA control mechanisms like mbind(2) don't work since the memory isn't directly mapped to userspace when allocations occur. Fuad's work [1] provides the necessary mmap capability, and this series leverages it to enable mbind(2).
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Applied the non-KVM change to kvm-x86 gmem. We're still tweaking and iterating on the KVM changes, but I fully expect them to land in 6.19.
Holler if you object to taking these through the kvm tree.
[1/7] mm/filemap: Add NUMA mempolicy support to filemap_alloc_folio() https://github.com/kvm-x86/linux/commit/601aa29f762f [2/7] mm/filemap: Extend __filemap_get_folio() to support NUMA memory policies https://github.com/kvm-x86/linux/commit/2bb25703e5bd [3/7] mm/mempolicy: Export memory policy symbols https://github.com/kvm-x86/linux/commit/e1b4cf7d6be3