Re: [Qemu-devel] [PATCH v2] hw/arm/virt-acpi - reserve ECAM space as PNP0C02 device

[Peter Maydell]

On 13 January 2017 at 17:32, Ard Biesheuvel <address@hidden> wrote:
> Linux for arm64 v4.10 and later will complain if the ECAM config space is
> not reserved in the ACPI namespace:
>
>   acpi PNP0A08:00: [Firmware Bug]: ECAM area [mem 0x3f000000-0x3fffffff] not 
> reserved in ACPI namespace
>
> The rationale is that OSes that don't consume the MCFG table should still
> be able to infer that the PCI config space MMIO region is occupied.
>
> So update the ACPI table generation routine to add this reservation.
>
> Signed-off-by: Ard Biesheuvel <address@hidden>
> ---
>  hw/arm/virt-acpi-build.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 085a61117378..50d52f685f68 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -310,6 +310,13 @@ static void acpi_dsdt_add_pci(Aml *scope, const 
> MemMapEntry *memmap,
>      Aml *dev_rp0 = aml_device("%s", "RP0");
>      aml_append(dev_rp0, aml_name_decl("_ADR", aml_int(0)));
>      aml_append(dev, dev_rp0);
> +
> +    Aml *dev_res0 = aml_device("%s", "RES0");
> +    aml_append(dev_res0, aml_name_decl("_HID", aml_string("PNP0C02")));
> +    crs = aml_resource_template();
> +    aml_append(crs, aml_memory32_fixed(base_ecam, size_ecam, 
> AML_READ_WRITE));
> +    aml_append(dev_res0, aml_name_decl("_CRS", crs));
> +    aml_append(dev, dev_res0);
>      aml_append(scope, dev);
>  }

This needs to be controlled via the machine class back-compat
machinery in hw/arm/virt.c so that it only happens for virt-2.9
and later.

thanks
-- PMM