On 20.08.2024 10:20, Juergen Gross wrote: > @@ -838,6 +839,31 @@ void __init xen_do_remap_nonram(void) > pr_info("Remapped %u non-RAM page(s)\n", remapped); > } > > +/* > + * Xen variant of acpi_os_ioremap() taking potentially remapped non-RAM > + * regions into acount. > + * Any attempt to map an area crossing a remap boundary will produce a > + * WARN() splat. > + */ > +static void __iomem *xen_acpi_os_ioremap(acpi_physical_address phys, > + acpi_size size) > +{ > + unsigned int i; > + struct nonram_remap *remap = xen_nonram_remap; const (also in one of the functions in patch 5)? > + for (i = 0; i < nr_nonram_remap; i++) { > + if (phys + size > remap->maddr && > + phys < remap->maddr + remap->size) { > + WARN_ON(phys < remap->maddr || > + phys + size > remap->maddr + remap->size); > + phys = remap->paddr + phys - remap->maddr; > + break; > + } > + } > + > + return x86_acpi_os_ioremap(phys, size); > +} At least this, perhaps also what patch 5 adds, likely wants to be limited to the XEN_DOM0 case? Or else I wonder whether ... > @@ -850,6 +876,10 @@ void __init xen_add_remap_nonram(phys_addr_t maddr, phys_addr_t paddr, > BUG(); > } > > + /* Switch to the Xen acpi_os_ioremap() variant. */ > + if (nr_nonram_remap == 0) > + acpi_os_ioremap = xen_acpi_os_ioremap; ... this would actually build when XEN_DOM0=n. I'm actually surprised there's no Dom0-only code section in this file, where the new code could then simply be inserted. Jan