Hi, On Thu, Jan 31, 2019 at 06:17:32PM +0800, lantianyu1...@gmail.com 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