Re: paravirt & xen & SMP

[Jeremy Fitzhardinge <jeremy@goop.org>]

Gerd Hoffmann wrote:
> Anyone has this working?  Looks like there is a chicken-and-egg issue
> with pda setup:
>
>   * xen_load_gdt() uses multicalls, thus depends on cpu-specific
>     variables (per-cpu mc buffer) which in turn requires pda being
>     setup already.
>   * pda setup can't be done before xen_load_gdt() ...
>   

Good point.  I haven't done any SMP work yet, so if anything works at
all it is pure luck.

> Next question while looking at xen_load_gdt(): why does it use
> multicalls in the first place?  Seems that function puts only one
> hypercall into the multicall array, so there is no obvious point in
> using multicalls ...
>   

I think you're right; I probably converted it when I swept through and
did the others without really thinking about the bootstrap consequences.

    J