On Thu, May 11, 2023 at 02:05:45PM +0200, Jan Beulich wrote: > Somewhat like port CF9 this may have a bit controlling the CPU's INIT# > signal, and it also may have a bit involved in the driving of A20M#. > Neither of these - just like CF9 - we want to allow Dom0 to drive. > > Signed-off-by: Jan Beulich <[email protected]>
Acked-by: Roger Pau Monné <[email protected]> I'm kind of concerned that such ports might be used for other stuff not described in the specifications I'm looking at, I guess we will find out. > > --- a/xen/arch/x86/dom0_build.c > +++ b/xen/arch/x86/dom0_build.c > @@ -500,6 +500,10 @@ int __init dom0_setup_permissions(struct > rc |= ioports_deny_access(d, 0x40, 0x43); > /* PIT Channel 2 / PC Speaker Control. */ > rc |= ioports_deny_access(d, 0x61, 0x61); > + > + /* INIT# and alternative A20M# control. */ > + rc |= ioports_deny_access(d, 0x92, 0x92); I do wonder whether it would make sense to create an array of [start, end] IO ports to deny access to, so that we could loop over them and code a single call to ioports_deny_access(). Maybe that's over engineering it. Thanks, Roger.
