Commit 36ea3979 authored Aug 28, 2018 by Marc-André Lureau Committed by Paolo Bonzini Nov 27, 2018

hostmem-memfd: honour share=on/off property



The share=on/off property is used to modified mmap() MAP_SHARED
setting. Make it on by default for convenience and compatibility
reasons.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 15ffb43c

backends/hostmem-memfd.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -59,7 +59,8 @@ memfd_backend_memory_alloc(HostMemoryBackend backend, Error *errp)

		name = object_get_canonical_path(OBJECT(backend));
		memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
		name, backend->size, true, fd, errp);
		name, backend->size,
		backend->share, fd, errp);
		g_free(name);
		}

		@@ -131,6 +132,7 @@ memfd_backend_instance_init(Object *obj)

		/* default to sealed file */
		m->seal = true;
		MEMORY_BACKEND(m)->share = true;
		}

		static void

qemu-options.hx

+3 −1

Original line number	Diff line number	Diff line
		@@ -4025,7 +4025,7 @@ Memory backend objects offer more control than the @option{-m} option that is
		traditionally used to define guest RAM. Please refer to
		@option{memory-backend-file} for a description of the options.

		@item -object memory-backend-memfd,id=@var{id},merge=@var{on\|off},dump=@var{on\|off},prealloc=@var{on\|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default\|preferred\|bind\|interleave},seal=@var{on\|off},hugetlb=@var{on\|off},hugetlbsize=@var{size}
		@item -object memory-backend-memfd,id=@var{id},merge=@var{on\|off},dump=@var{on\|off},share=@var{on\|off},prealloc=@var{on\|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default\|preferred\|bind\|interleave},seal=@var{on\|off},hugetlb=@var{on\|off},hugetlbsize=@var{size}

		Creates an anonymous memory file backend object, which allows QEMU to
		share the memory with an external process (e.g. when using
		@@ -4047,6 +4047,8 @@ with the @option{seal} option (requires at least Linux 4.16).
		Please refer to @option{memory-backend-file} for a description of the
		other options.

		The @option{share} boolean option is @var{on} by default with memfd.

		@item -object rng-random,id=@var{id},filename=@var{/dev/random}

		Creates a random number generator backend which obtains entropy from