Re: [PATCH] do not p2m_invalidate_root when iommu_use_hap_pt

[Julien Grall <julien@xxxxxxx>]

Hi Stefano,

On 04/08/2021 01:08, Stefano Stabellini wrote:
> > > diff --git a/xen/arch/arm/arm64/vsysreg.c b/xen/arch/arm/arm64/vsysreg.c
> > > index caf17174b8..125a9281fc 100644
> > > --- a/xen/arch/arm/arm64/vsysreg.c
> > > +++ b/xen/arch/arm/arm64/vsysreg.c
> > > @@ -105,6 +105,13 @@ void do_sysreg(struct cpu_user_regs *regs,
> > >        case HSR_SYSREG_DCISW:
> > >        case HSR_SYSREG_DCCSW:
> > >        case HSR_SYSREG_DCCISW:
> > > +        if ( iommu_use_hap_pt(current->domain) )
> > > +        {
> > > +            gdprintk(XENLOG_ERR,
> > > +                     "d%u uses set/way cache flushes with the IOMMU on. It
> > > cannot work. Replace set/way instructions with dc [ci]vac and retry.
> > > Injecting exception into the guest now.\n",
> > This line would be far too long to print on the serial. I think you want to
> > add a few newline here.
> Fair enough but I'll try to keep most info on the same line because
> otherwise with a dom0less boot it can get confusing. I suggest:
I am not quite too sure to understand why it would get confusing with 
dom0less. Can you give an example?
Cheers,

--
Julien Grall