Guest initiated atomic instructions for shared memory page host copy on write

A computing apparatus comprising:

• a memory to store instructions;
• and
• a processing device, operatively coupled to the memory, to execute the instructions, wherein the processing device is to:
• detect, by the processing device, a direct memory access (DMA) write request for a device assigned to a guest operating system to perform a DMA write to a shared page of memory, wherein the shared page of memory has a write protection attribute to cause a protection page fault upon an attempt to write to the shared page of memory;
• read, by the processing device, a portion of the shared page of memory from a location of the shared page of memory;
• execute, by the processing device, an atomic instruction that writes a value of the portion of the shared page of memory back to the location of the shared page of memory to trigger the protection page fault in view of the write protection attribute;
• and
• upon executing the atomic instruction, send, by the processing device, the DMA write request to the device to cause the device to write to a writable copy of the shared page of memory, the writable copy created responsive to the protection page fault.