Re: [Xen-devel] [PATCH v2 07/11] xen/hvmlite: Initialize context for secondary VCPUs

[Boris Ostrovsky]

On 02/04/2016 07:58 AM, Doug Goldstein wrote:
> On 2/2/16 10:58 AM, Boris Ostrovsky wrote:
> > On 02/02/2016 11:21 AM, David Vrabel wrote:
> > > This needs some more description in the commit message.
> > >
> > > > --- a/arch/x86/xen/smp.c
> > > > +++ b/arch/x86/xen/smp.c
> > > [...]
> > > > +        hctxt->cpu_regs.x86_32.cs_base = 0;
> > > > +        hctxt->cpu_regs.x86_32.cs_limit = ~0u;
> > > > +        hctxt->cpu_regs.x86_32.cs_ar = 0xc9b;
> > > > +        hctxt->cpu_regs.x86_32.ds_base = 0;
> > > > +        hctxt->cpu_regs.x86_32.ds_limit = ~0u;
> > > > +        hctxt->cpu_regs.x86_32.ds_ar = 0xc93;
> > > > +        hctxt->cpu_regs.x86_32.es_base = 0;
> > > > +        hctxt->cpu_regs.x86_32.es_limit = ~0u;
> > > > +        hctxt->cpu_regs.x86_32.es_ar = 0xc93;
> > > > +        hctxt->cpu_regs.x86_32.ss_base = 0;
> > > > +        hctxt->cpu_regs.x86_32.ss_limit = ~0u;
> > > > +        hctxt->cpu_regs.x86_32.ss_ar = 0xc93;
> > > > +        hctxt->cpu_regs.x86_32.tr_base = 0;
> > > > +        hctxt->cpu_regs.x86_32.tr_limit = 0xff;
> > > > +        hctxt->cpu_regs.x86_32.tr_ar = 0x8b;
> > > Lots of hard-coded values here.  Should this be #defined somewhere?
> > We also don't need to set bases to zero since hctxt is kzalloc'd. I'll
> > remove that and add a comment.
> >
> > As for macros --- I couldn't find the bits defined symbolically anywhere
> > and since this is the only place this is used the macros would be local
> > here.
> >
> > -boris
> It could be useful to have them defined locally if only to give them
> some more meaning by having a name rather than 0x8b. Just a thought.

Yes, I'll do that (or at least have a comment explaining the bits).

Looks like this we should wait with this series though until we figure 
out APIC emulation status.

-boris