Subject: Re: RFC: virtio-hostmem (+ Continuation of discussion from [virtio-dev] Memory sharing device)
Michael, thank you for your comments. > I'm not sure how does above answer the comment. Sorry for leaving this unclear, our guest driver tells the device guest's page size and then we do aligning-unaligning. > To try and put things in your terms, if you try to map a range of memory > you get access to a page that can be bigger than the range you asked > for. This is correct. > It can cause two ranges to violate a security boundary, cause > information leaks, etc. Could you please correct me if I am wrong. If I ask glMapBufferRange (without hosts and guests) for a 1K buffer with 4K pages, I will have access to other 3K. If a driver decides to put sensitive bits there - will this be the same situation? We assume pages are not shared between processes. If this assumption does not work then it is hard to share arbitrary pointers. Regards, Roman.