Mechanisms to save user/kernel copy for cross device communications

A system to copy data comprising:

• a memory;
• and
• a processor, coupled to the memory, configured to:
• map, with kernel permissions, a first virtual memory address to a first physical memory address in the memory;
• map, with kernel permissions, a second virtual memory address to a second physical memory address in the memory;
• receive the data at the first physical memory address;
• map, with user permissions, a third virtual memory address to the first physical memory address;
• and
• copy, with kernel permissions, the data from the first physical memory address to the second physical memory address.

A non-transitory computer readable medium comprising instructions that when executed by a processor cause the processor to:

• map, with kernel permissions, a first virtual memory address to a first physical memory address;
• map, with kernel permissions, a second virtual memory address to a second physical memory address;
• receive data at the first physical memory address;
• map, with user permissions, a third virtual memory address to the first physical memory address;
• and
• copy, with kernel permissions, the data from the first physical memory address to the second physical memory address.