[PATCH] hostmem/shm: Allow shm memory backend serve as shared memory for coco-VMs

[Xiaoyao Li]

shm can surely serve as the shared memory for coco-VMs. But currently it
doesn't check the backend->guest_memfd to pass down the RAM_GUEST_MEMFD
flag. It leads to failure when creating coco-VMs (e.g., TDX guest) which
require private mmeory.

Set and pass down RAM_GUEST_MEMFD when backend->guest_memfd is true, to
allow shm memory backend serve as shared memory for coco-VMs.

cc: Stefano Garzarella <sgarz...@redhat.com>
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com>
---
 backends/hostmem-shm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/backends/hostmem-shm.c b/backends/hostmem-shm.c
index f66211a2ec92..806e2670e039 100644
--- a/backends/hostmem-shm.c
+++ b/backends/hostmem-shm.c
@@ -54,6 +54,7 @@ have_fd:
     /* Let's do the same as memory-backend-ram,share=on would do. */
     ram_flags = RAM_SHARED;
     ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
+    ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0;
 
     return memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
                                               backend_name, backend->size,
-- 
2.43.0