Re: [PATCH v3 2/2] x86/xen: Allow per-domain usage of hardware virtualized APIC

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Thu, Feb 24, 2022 at 03:16:08PM +0100, Jan Beulich wrote:
> On 18.02.2022 18:29, Jane Malalane wrote:
> > --- a/xen/arch/x86/hvm/vmx/vmx.c
> > +++ b/xen/arch/x86/hvm/vmx/vmx.c
> > @@ -3333,15 +3333,15 @@ static void vmx_install_vlapic_mapping(struct vcpu 
> > *v)
> >  
> >  void vmx_vlapic_msr_changed(struct vcpu *v)
> >  {
> > -    int virtualize_x2apic_mode;
> > +    bool virtualize_x2apic_mode;
> >      struct vlapic *vlapic = vcpu_vlapic(v);
> >      unsigned int msr;
> >  
> >      virtualize_x2apic_mode = ( (cpu_has_vmx_apic_reg_virt ||
> >                                  cpu_has_vmx_virtual_intr_delivery) &&
> > -                               cpu_has_vmx_virtualize_x2apic_mode );
> > +                               v->domain->arch.hvm.assisted_x2apic );
> 
> Following from my comment on patch 1, I'd expect this to become a simple
> assignment of v->domain->arch.hvm.assisted_x2apic (at which point the
> local variable could go away), just like ...

I think we want to keep assisted_x{2}apic mapped to
SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES and
SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE respectively, so that in the
future we could add further controls for
SECONDARY_EXEC_APIC_REGISTER_VIRT and interrupt delivery.

Thanks, Roger.