Re: [PATCH 2/3] HYPERV/IOMMU: Add Hyper-V stub IOMMU driver

[Tianyu Lan]

Hi Joerg:
             Thanks for your review.

On Sat, Feb 2, 2019 at 12:34 AM Joerg Roedel <joro@xxxxxxxxxx> wrote:
>
> Hi,
>
> On Thu, Jan 31, 2019 at 06:17:32PM +0800, lantianyu1986@xxxxxxxxx wrote:
> > +config HYPERV_IOMMU
> > +     bool "Hyper-V stub IOMMU support"
>
> This is not a real IOMMU driver, it only implements IRQ remapping
> capabilities. Please change the name to reflect that, e.g. to
> "Hyper-V IRQ Remapping Support" or something like that.

Yes, that makes sense. Will update.

>
> > +static int __init hyperv_prepare_irq_remapping(void)
> > +{
> > +     struct fwnode_handle *fn;
> > +     u32 apic_id;
> > +     int i;
> > +
> > +     if (x86_hyper_type != X86_HYPER_MS_HYPERV ||
> > +         !x2apic_supported())
> > +             return -ENODEV;
> > +
> > +     fn = irq_domain_alloc_named_id_fwnode("HYPERV-IR", 0);
> > +     if (!fn)
> > +             return -EFAULT;
>
> Why does this return -EFAULT? I guess there is no fault happening in
> irq_domain_alloc_named_id_fwnode()...

Yes, â-ENOMEMâ should be more accurate.

-- 
Best regards
Tianyu Lan