KVM: arm64: Introduce a Hyp buddy page allocator

When memory protection is enabled, the hyp code will require a basic
form of memory management in order to allocate and free memory pages at
EL2. This is needed for various use-cases, including the creation of hyp
mappings or the allocation of stage 2 page tables.

To address these use-case, introduce a simple memory allocator in the
hyp code. The allocator is designed as a conventional 'buddy allocator',
working with a page granularity. It allows to allocate and free
physically contiguous pages from memory 'pools', with a guaranteed order
alignment in the PA space. Each page in a memory pool is associated
with a struct hyp_page which holds the page's metadata, including its
refcount, as well as its current order, hence mimicking the kernel's
buddy system in the GFP infrastructure. The hyp_page metadata are made
accessible through a hyp_vmemmap, following the concept of
SPARSE_VMEMMAP in the kernel.

Acked-by: Will Deacon <[email protected]>
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

0 files changed, 0 insertions, 0 deletions