"-mem-path" corresponds to "memory-backend-file,share=off" and, therefore, creates a private COW mapping of the file. For multi-proces QEMU, we need proper shared file-backed memory.
Let's make that clearer. Signed-off-by: David Hildenbrand <da...@redhat.com> --- docs/devel/multi-process.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/docs/devel/multi-process.rst b/docs/devel/multi-process.rst index e4801751f2..4ef539c0b0 100644 --- a/docs/devel/multi-process.rst +++ b/docs/devel/multi-process.rst @@ -409,8 +409,9 @@ the initial messages sent to the emulation process is a guest memory table. Each entry in this table consists of a file descriptor and size that the emulation process can ``mmap()`` to directly access guest memory, similar to ``vhost_user_set_mem_table()``. Note guest memory -must be backed by file descriptors, such as when QEMU is given the -*-mem-path* command line option. +must be backed by shared file-backed memory, for example, using +*-object memory-backend-file,share=on* and setting that memory backend +as RAM for the machine. IOMMU operations ^^^^^^^^^^^^^^^^ -- 2.41.0