> -----Original Message----- > From: Xen-devel [mailto:xen-devel-boun...@lists.xen.org] On Behalf Of Jan > Beulich > Sent: 27 September 2017 15:42 > To: Paul Durrant <paul.durr...@citrix.com> > Cc: Andrew Cooper <andrew.coop...@citrix.com>; xen- > de...@lists.xenproject.org > Subject: Re: [Xen-devel] [PATCH v7 01/12] x86/mm: allow a privileged PV > domain to map guest mfns > > >>> On 27.09.17 at 16:22, <paul.durr...@citrix.com> wrote: > >> From: Jan Beulich [mailto:jbeul...@suse.com] > >> Sent: 27 September 2017 14:31 > >> >>> On 27.09.17 at 14:49, <paul.durr...@citrix.com> wrote: > >> > Ok, I'll claim the final cmd value then. > >> > >> Final? We've got 5 left (for a total of 3 bits) afaict. > > > > Really? Maybe I misread... looks like only 2 bits to me. > > Maybe you and I looked in different places. I'm deriving this from > > cmd = req.ptr & (sizeof(l1_pgentry_t)-1); > > switch ( cmd ) > > in do_mmu_update(). Only 32-bit non-PAE guests would have been > limited to 2 bits.
Ah, ok. I was going off what it says in the header, where the comments state that [0:1] are command bits and [:2] are address bits, but for 64-bit or PAE guests then it makes sense that bit 2 is up for grabs. Anyway I can use 3, which still fits in bits [0:1]. Paul > > Jan > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > https://lists.xen.org/xen-devel _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
