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

[Joerg Roedel]

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.

> +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()...


	Joerg