[Qemu-devel] [PATCH v6 0/9] Add memfd memory backend

[Marc-André Lureau]

Add a new Linux-specific memory backend, similar to hostmem-file,
except that it doesn't need file path. It also try to enforce memory
sealing if available. It is thus slightly easier and secure, and is
compatible with transparent huge-pages since Linux 4.8.

Since Linux 4.14, memfd supports explicit hugetlb, however without
sealing.

v6:
- add hugetlbsize option
- run vhost-user read-guest-mem test with memfile & memfd backend

v5:
- add memfd hugetlb support
- add seal and hugeltb options to memfd memory backend
- update qemu-option to explain sharing works with vhost-user for now
- rebased, misc code changes

v4:
- rebased, now that preliminary patches are merged

v3:
- make vhost-user-test use memfd only if possible
- rebased

v1->v2:
- make it linux-specific
- minor changes and commit message tweaks

Marc-André Lureau (9):
  memfd: split qemu_memfd_alloc()
  memfd: remove needless include
  memfd: add error argument, instead of perror()
  memfd: add hugetlb support
  memfd: add hugetlbsize argument
  Add memfd based hostmem
  tests: keep compiling failing vhost-user tests
  vhost-user-test: make read-guest-mem setup its own qemu
  tests: use memfd in vhost-user-test

 include/qemu/memfd.h     |   4 +-
 backends/hostmem-memfd.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio/vhost.c        |   8 ++-
 tests/vhost-user-test.c  | 160 +++++++++++++++++++++++++++-----------------
 util/memfd.c             | 115 ++++++++++++++++++++------------
 backends/Makefile.objs   |   2 +
 qemu-options.hx          |  23 +++++++
 7 files changed, 378 insertions(+), 102 deletions(-)
 create mode 100644 backends/hostmem-memfd.c

-- 
2.15.0.rc0.40.gaefcc5f6f