memory: add RAM_PRIVATE

Define the RAM_PRIVATE flag.

In RAMBlock creation functions, if MAP_SHARED is 0 in the flags parameter,
in a subsequent patch the implementation may still create a shared mapping
if other conditions require it.  Callers who specifically want a private
mapping, eg for objects specified by the user, must pass RAM_PRIVATE.

After RAMBlock creation, MAP_SHARED in the block's flags indicates whether
the block is shared or private, and MAP_PRIVATE is omitted.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1736967650-129648-6-git-send-email-steven.sistare@oracle.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
This commit is contained in:
Steve Sistare 2025-01-15 11:00:31 -08:00 committed by Fabiano Rosas
parent 9fb40bb962
commit 6169f11936
6 changed files with 26 additions and 7 deletions

View file

@ -82,7 +82,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
backend->aligned = true;
name = host_memory_backend_get_name(backend);
ram_flags = backend->share ? RAM_SHARED : 0;
ram_flags = backend->share ? RAM_SHARED : RAM_PRIVATE;
ram_flags |= fb->readonly ? RAM_READONLY_FD : 0;
ram_flags |= fb->rom == ON_OFF_AUTO_ON ? RAM_READONLY : 0;
ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;