On Mon, Nov 23, 2020 at 07:28:22AM -0800, Andy Lutomirski wrote: > On Mon, Nov 23, 2020 at 1:54 AM Mike Rapoport <rppt@xxxxxxxxxx> wrote: > > > > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > > > Hi, > > > > This is an implementation of "secret" mappings backed by a file descriptor. > > > > The file descriptor backing secret memory mappings is created using a > > dedicated memfd_secret system call The desired protection mode for the > > memory is configured using flags parameter of the system call. The mmap() > > of the file descriptor created with memfd_secret() will create a "secret" > > memory mapping. The pages in that mapping will be marked as not present in > > the direct map and will have desired protection bits set in the user page > > table. For instance, current implementation allows uncached mappings. > > I'm still not ready to ACK uncached mappings on x86. I'm fine with > the concept of allowing privileged users to create UC memory on x86 > for testing and experimentation, but it's a big can of worms in > general. Ok, let's move forward without UC. -- Sincerely yours, Mike.
