RE: [Xen-ia64-devel] PATCH: rewrite vcpu_get_psr

[tgingold@xxxxxxx]

Quoting "Xu, Anthony" <anthony.xu@xxxxxxxxx>:
> Machine psr dt it rt are always 1.
Sure!

> While this code segment is used to emulate guest execution of "mov from psr"
> From the view of guest OS, vpsr dt it rt can be any value.
It depends on how these bits are used.

> In xenodomaim,
> There are only two situations.
> Virtual mode;  vpsr.it=dt=rt=1.
> Physical mode: vpsr.dt=0, vpsr.it=vpsr.rt=1, which happens in linux OS tlb
> fault
> related handlers.

vpsr.it=dt=rt=0 is also supported (initial boot and possibly PAL calls).

Should vpsr.dt set metaphysical mode and other bits ignored ?

But Xen should be coherent on this point.

>
> In vti-domain.
> We support more situations except for above two.
>
> Vpsr.it=dt=rt=0, this happens when guest calls PAL call, which can be called
> only
> in physical mode.
>
> Vpsr.it=rt=0, vpsr.dt=1, this happens at the very beginning of windows boot.
Interesting!

Tristan.

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