Re: [Qemu-devel] [PATCH 0/5] hostmem-file: Add "persistent" option

[Eduardo Habkost]

On Wed, Jun 14, 2017 at 05:29:55PM -0300, Eduardo Habkost wrote:
> This series adds a new "persistent" option to
> memory-backend-file.  The new option it will be useful if
> somebody is sharing RAM contents on a file using share=on, but
> don't need it to be flushed to disk when QEMU exits.
> 
> Internally, it will trigger a madvise(MADV_REMOVE) or
> fallocate(FALLOC_FL_PUNCH_HOLE) call when the memory backend is
> destroyed.
> 
> To make we actually trigger the new code when QEMU exits, the
> first patch in the series ensures we destroy all user-created
> objects when exiting QEMU.

In addition to the additional fixes I have planned for v2, it
looks like this series won't be enough: the memory regions will
still have a non-zero reference count when exiting QEMU.  I'm not
sure how much extra work will be required to fix that.

-- 
Eduardo