hw/arm/virt-acpi - reserve ECAM space as PNP0C02 device

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 <ard.biesheuvel@linaro.org>
Message-id: 1484328738-21149-1-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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);
 }