> -----Original Message----- > From: Jan Beulich [mailto:jbeul...@suse.com] > Sent: Friday, June 12, 2015 6:35 PM > To: Wu, Feng > Cc: andrew.coop...@citrix.com; george.dun...@eu.citrix.com; Tian, Kevin; > Zhang, Yang Z; xen-devel@lists.xen.org; k...@xen.org > Subject: RE: [RFC v2 07/15] vt-d: Add API to update IRTE when VT-d PI is used > > >>> On 12.06.15 at 11:40, <feng...@intel.com> wrote: > >> -----Original Message----- > >> From: Jan Beulich [mailto:jbeul...@suse.com] > >> >>> On 08.05.15 at 11:07, <feng...@intel.com> wrote: > >> > +static inline void setup_posted_irte( > >> > + struct iremap_entry *new_ire, struct pi_desc *pi_desc, uint8_t > gvec) > >> > +{ > >> > + new_ire->post.urg = 0; > >> > + new_ire->post.vector = gvec; > >> > + new_ire->post.pda_l = (((u64)virt_to_maddr(pi_desc)) >> > >> > + (32 - PDA_LOW_BIT)) & > PDA_MASK(LOW); > >> > + new_ire->post.pda_h = (((u64)virt_to_maddr(pi_desc)) >> 32) & > >> > + PDA_MASK(HIGH); > >> > >> Looking at this another time I can't see what the and-ing with > >> PAD_MASK() is supposed to be good for. > > > > I cannot understand this well. Do you mean we don't need and PDA_MASK() > > here? > > Correct - the bitfield width (where the data gets stored into) already > enforces the intended truncation afaict.
We may not need PDA_MASK(HIGH), but is PDA_MASK(LOW) really unnecessary here? Thanks, Feng > > Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
