[Julian Stecklina]
Hello, let's say in my rootserver I need a contiguous block of memory 1 MB in size. I would request this memory from Sigma0 via L4_Sigma0_GetAny and get a single Flexpage of this size. In order to implement a fine-grained write-barrier on parts of this memory block, I need to make individual pages of this block read-only. As I understand it, the privileged system call MemoryControl provides this functionality, but:
a) it is privileged, but all my servers would need this functionality. How is this efficiently accomplished?
b) MemoryControl seems to operate on whole fpages only. How do I split a flexpage?
You don't need MemoryControl() to make things read-only. Just map it on with read-only permissions or revoke the write permission using Unmap() with appropriate parameters.
eSk