About Huawei computing virtualization, memory multiplexing features using shared memory, which of the following statement is correct? (Multiple choice)

About Huawei computing virtualization, memory multiplexing features using shared memory, which of the following statement is correct? (Multiple choice)
A . shared memory VM should be the same OS
B . virtual machine read-only #9 for shared memory
C . when a virtual machine need to do write operation to memory, you need to open up another memory space, and modify the mapping
D . create shared/remove shared will bring extra overhead

Answer: ABCD