On Wed, Jan 23, 2019 at 10:48:20AM +1100, Paul Mackerras wrote: > On Tue, Jan 22, 2019 at 07:59:35AM -0800, Ram Pai wrote: > > From: Michael Anderson <andmike@xxxxxxxxxxxxx> > > > > The Nest_MMU needs to know the address of the Partition table (PT). > > However the PT is in secure memory, and nestMMU cannot access secure > > memory. Hence hypevisor will continue to use a Partition table of > > its own. It will have PATE entries for HV and for Normal virtual > > machines. The same entries are also in the UV's PT. The HV's PT > > is programmed with the nest MMU. > > This isn't a good patch description. It's confusing because it > doesn't start with the primary motivation of the patch - which is that > when running under an ultravisor, the ultravisor controls the real > partition table and has it in secure memory where the hypervisor can't > access it, and therefore we (the HV) have to do a ucall whenever we > want to update an entry. Once you have explained that, then you can > explain the secondary aspect of the patch, which is that the HV still > keeps a copy of its view of the partition table in normal memory so > that the nest MMU can access it. > > > Suggested-by: Ryan Grimm <grimm@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx> > > [device node name to ibm,ultravisor] > > Signed-off-by: Michael Anderson <andmike@xxxxxxxxxxxxx> > > Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx> > > If Michael Anderson wrote the patch and sent it to you, and you sent > it to the list, why is Maddy's signoff relevant? Was the original > version of the patch actually written by Maddy? Yes. this patch description needs a good amount work. A couple of related patches; some by Michael and some by me and some bug fixes by Maddy, were merged leading to this signoff cocktail and incoherent description. This was my first attempt to bring a logical order to our internal set of patches, which I agree has some more way to go. :( Thanks, RP
