Re: [Xen-devel] [PATCH v2 2/4] x86/pvh: Set 32b PVH guest mode in XEN_DOMCTL_set_address_size

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

On 07/07/2015 05:15 AM, Jan Beulich wrote:
> > > > On 29.06.15 at 22:21, <boris.ostrovsky@xxxxxxxxxx> wrote:
> > --- a/xen/arch/x86/domain.c
> > +++ b/xen/arch/x86/domain.c
> > @@ -377,25 +377,25 @@ int switch_compat(struct domain *d)
> >       struct vcpu *v;
> >       int rc;
> >   
> > -    if ( is_pvh_domain(d) )
> > -    {
> > -        printk(XENLOG_G_INFO
> > -               "Xen currently does not support 32bit PVH guests\n");
> > -        return -EINVAL;
> > -    }
> > -
> >       if ( !may_switch_mode(d) )
> >           return -EACCES;
> >       if ( has_32bit_shinfo(d) )
> >           return 0;
> >   
> > -    d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 1;
> > +    d->arch.has_32bit_shinfo = 1;
> > +    if ( is_pv_domain(d) )
> > +        d->arch.is_32bit_pv = 1;
> >   
> >       for_each_vcpu( d, v )
> >       {
> >           rc = setup_compat_arg_xlat(v);
> >           if ( !rc )
> > -            rc = setup_compat_l4(v);
> > +        {
> > +            if ( !is_pvh_domain(d) )
> > +                rc = setup_compat_l4(v);
> > +            else
> > +                rc = hvm_set_mode(v, 4);
> > +        }
> >           if ( rc )
> >               goto undo_and_fail;
> >       }
> > @@ -410,7 +410,7 @@ int switch_compat(struct domain *d)
> >       {
> >           free_compat_arg_xlat(v);
> >   
> > -        if ( !pagetable_is_null(v->arch.guest_table) )
> > +        if ( !is_pvh_domain(d) && !pagetable_is_null(v->arch.guest_table) )
> >               release_compat_l4(v);
> >       }
> >   
> And no respective change to switch_native()?


> > @@ -6491,6 +6490,20 @@ enum hvm_intblk nhvm_interrupt_blocked(struct vcpu *v)
> >       return hvm_funcs.nhvm_intr_blocked(v);
> >   }
> >   
> > +int hvm_set_mode(struct vcpu *v, int mode)
> > +{
> > +    if ( mode == 4 )
> > +    {
> > +        v->arch.hvm_vcpu.guest_efer &= ~(EFER_LMA | EFER_LME);
> > +        hvm_update_guest_efer(v);
> > +    }
> > +
> > +    if ( hvm_funcs.set_mode )
> > +        return hvm_funcs.set_mode(v, mode);
> > +
> > +    return 0;
> > +}
> -EOPNOTSUPP?
Why do you think this should be an error? I probably will need to update 
this to handle mode==8 for calls from switch_native() as you pointed out 
above but in general it seems to me it should be OK if this procedure 
doesn't do anything. Below too.
-boris

> > --- a/xen/arch/x86/hvm/vmx/vmx.c
> > +++ b/xen/arch/x86/hvm/vmx/vmx.c
> > @@ -1763,6 +1763,22 @@ static void vmx_enable_msr_exit_interception(struct 
> > domain *d)
> >                                            MSR_TYPE_W);
> >   }
> >   
> > +int vmx_set_mode(struct vcpu *v, int mode)
> > +{
> > +
> > +    if ( !is_pvh_vcpu(v) )
> > +        return 0;
> > +
> > +    if ( mode == 4 )
> > +    {
> > +        vmx_vmcs_enter(v);
> > +        __vmwrite(GUEST_CS_AR_BYTES, 0xc09b);
> > +        vmx_vmcs_exit(v);
> > +    }
> > +
> > +    return 0;
> > +}
> Again -EOPNOTSUPP?
>
> Jan

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