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

[Marc-André Lureau]

Hi

On Mon, Oct 23, 2017 at 4:18 PM, Marc-André Lureau
<address@hidden> wrote:
> 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.

A little update here, 4.16 is likely to support sealing with hugetlb
too (patches are in -mm tree). This should make memfd the prefered
backend for sharing memory with a vhost-user backend.

please review.
thanks

>
> 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
>
>



-- 
Marc-André Lureau