Hi all,

This is the POC to enable in-place conversion and hugetlb support of
gmem (guest memfd) in QEMU. It can work with 1G gmem support series[1] and
TDX hugepage support series[2] to run TDX guest with hugepage. I don't
have SNP environment and don't know how it goes with SNP.

It is just the POC and we share it to show how QEMU work with gmem ABI.

The POC uses the simple implementation that switches to use in-place
conversion and hugetlb when it is supported and it doesn't introduce new
interface in QEMU so that existing command line to boot TDX can work without
any change.

Please go to each patch (specifically patch 3/4/5) to discuss the ABI
usage, potential issue, and maybe the upstreamable design.

[1] https://lore.kernel.org/all/cover.1747264138.git.ackerleytng@google.com/
[2] https://lore.kernel.org/all/20250424030033.32635-1-yan.y.zhao@intel.com/

Xiaoyao Li (4):
  update-linux-headers: Add guestmem.h
  headers: Fetch gmem updates
  memory/guest_memfd: Enable hugetlb support
  [HACK] memory: Don't enable in-place conversion for internal
    MemoryRegion with gmem

Yan Zhao (1):
  memory/guest_memfd: Enable in-place conversion when available

 accel/kvm/kvm-all.c             | 82 ++++++++++++++++++++++++---------
 accel/stubs/kvm-stub.c          |  2 +
 include/system/kvm.h            |  2 +
 include/system/memory.h         |  5 ++
 include/system/ramblock.h       |  1 +
 linux-headers/linux/guestmem.h  | 29 ++++++++++++
 linux-headers/linux/kvm.h       | 18 ++++++++
 scripts/update-linux-headers.sh |  2 +-
 system/memory.c                 |  9 +++-
 system/physmem.c                | 40 ++++++++++++++--
 10 files changed, 163 insertions(+), 27 deletions(-)
 create mode 100644 linux-headers/linux/guestmem.h

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2.43.0