Hi Christian, > > Hi Vivek, > > > [Kasireddy, Vivek] What if I do mmap() on the fd followed by mlock() > > or mmap() followed by get_user_pages()? If it still fails, would > > ioremapping the device memory and poking at the backing storage be an > > option? Or, if I bind the passthrough'd GPU device to vfio-pci and tap > > into the memory region associated with the device memory, can it be made to work? > > get_user_pages() is not allowed on mmaped DMA-bufs in the first place. > > Daniel is currently adding code to make sure that this is never ever used. > > > And, I noticed that for PFNs that do not have valid struct page > > associated with it, KVM does a memremap() to access/map them. Is this an option? > > No, even for system memory which has a valid struct page touching it when it is part of a > DMA-buf is illegal since the reference count and mapping fields in struct page might be > used for something different. > > Keep in mind that struct page is a heavily overloaded structure for different use cases. You > can't just use it for a different use case than what the owner of the page has intended it. [Kasireddy, Vivek] What is your recommended/acceptable way for doing what I am trying to do? Thanks, Vivek > > Regards, > Christian. > > > > > > > Thanks, > > Vivek > >> take care, > >> Gerd
