Re: [Xen-devel] [PATCH] x86/HVM: tie RTC emulation mode to enabling of Viridian emulation

[Paul Durrant <Paul.Durrant@xxxxxxxxxx>]

> -----Original Message-----
> From: Jan Beulich [mailto:JBeulich@xxxxxxxx]
> Sent: 02 July 2013 09:22
> To: Paul Durrant
> Cc: George Dunlap; xen-devel; Keir (Xen.org); Tim (Xen.org)
> Subject: RE: [PATCH] x86/HVM: tie RTC emulation mode to enabling of
> Viridian emulation
> 
> >>> On 02.07.13 at 10:01, Paul Durrant <Paul.Durrant@xxxxxxxxxx> wrote:
> >>  -----Original Message-----
> >> From: Jan Beulich [mailto:JBeulich@xxxxxxxx]
> >> Sent: 02 July 2013 08:03
> >> To: xen-devel
> >> Cc: Paul Durrant; George Dunlap; Keir (Xen.org); Tim (Xen.org)
> >> Subject: [PATCH] x86/HVM: tie RTC emulation mode to enabling of
> Viridian
> >> emulation
> >>
> >> As the mode not conforming to the hardware specification (by allowing
> >> the guest to skip the REG C reads in its interrupt handler) is a
> >> Viridian invention, it seems logical to tie this mode to that extension
> >> being enabled. If the extension is disabled, proper hardware emulation
> >> will be done instead.
> >>
> >> The main thing necessary here is the synchronization of the RTC
> >> emulation code and the setting of the respective flag in hvmloader's
> >> creation of the ACPI WAET table.
> >>
> >
> > Do we need to hardcode no_ack in the viridian case? Can we not be more
> > flexible and just have the WAET reflect whatever mode is in use?
> 
> We could, but is the extra work involved in coding this up (would
> require a new HVM param) worth it? Newer Windows really wants
> it that way...
> 

Ok. Fair enough. I guess the parameter could be introduced should the need 
arise.

Ack-ed by: Paul Durrant <paul.durrant@xxxxxxxxxx>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel