On Wed, Apr 19, 2023 at 09:56:35AM +0200, Jan Beulich wrote: > On 18.04.2023 13:35, Roger Pau Monné wrote: > > On Tue, Apr 18, 2023 at 11:24:19AM +0200, Jan Beulich wrote: > >> ... in order to also intercept Dom0 accesses through the alias ports. > >> > >> Also stop intercepting accesses to the CMOS ports if we won't ourselves > >> use the CMOS RTC, because of there being none. > >> > >> Note that rtc_init() deliberately uses 16 as the upper loop bound, > >> despite probe_cmos_alias() using 8: The higher bound is benign now, but > >> would save us touching the code (or, worse, missing to touch it) in case > >> the lower one was doubled. > >> > >> Signed-off-by: Jan Beulich <jbeul...@suse.com> > > > > Reviewed-by: Roger Pau Monné <roger....@citrix.com> > > Thanks. > > >> --- a/xen/arch/x86/pv/emul-priv-op.c > >> +++ b/xen/arch/x86/pv/emul-priv-op.c > >> @@ -208,7 +208,7 @@ static bool admin_io_okay(unsigned int p > >> return false; > >> > >> /* We also never permit direct access to the RTC/CMOS registers. */ > > > > Hm, it's unclear to me whether the comment above would need updating: > > we don't allow direct access to the RTC/CMOS registers, but we allow > > direct access to the RTC/CMOS ports if there's no device behind. > > Right, but those ports then don't allow access to said registers. So > I think the comment is fine as is.
Yes, that's why I wasn't really sure whether to comment. The comment is formally correct, but it might lead to confusion if one doesn't carefully read 'RTC/CMOS registers' (vs RTC/CMOS IO ports). Anyway, sorry for the noise. Thanks, Roger.
