On Fri, Jul 14, 2017 at 6:37 AM, Ram Pai <linuxram@xxxxxxxxxx> wrote: > On Thu, Jul 13, 2017 at 12:45:00AM -0700, Ram Pai wrote: >> On Wed, Jul 12, 2017 at 01:28:25PM +1000, Balbir Singh wrote: >> > On Wed, 5 Jul 2017 14:21:51 -0700 >> > Ram Pai <linuxram@xxxxxxxxxx> wrote: >> > >> > > Initial plumbing to manage all the keys supported by the >> > > hardware. >> > > >> > > Total 32 keys are supported on powerpc. However pkey 0,1 >> > > and 31 are reserved. So effectively we have 29 pkeys. >> > > >> > > This patch keeps track of reserved keys, allocated keys >> > > and keys that are currently free. >> > >> > It looks like this patch will only work in guest mode? >> > Is that an assumption we've made? What happens if I use >> > keys when running in hypervisor mode? >> >> It works in supervisor mode, as a guest aswell as a bare-metal >> kernel. Whatever needs to be done in hypervisor mode >> is already there in power-kvm. > > I realize i did not answer your question accurately... > "What happens if I use keys when running in hypervisor mode?" > > Its not clear what happens. As far as I can tell the MMU does > not check key violation when in hypervisor mode. So effectively > I think, keys are ineffective when in hypervisor mode. keys are honored in hypervisor mode. I was just stating that we need a mechanism used by the hypervisor to partition the key space between guests and hypervisor. Balbir Singh
