[PATCH 05/13] microvm: add acpi_dsdt_add_virtio() for x86

[Gerd Hoffmann <kraxel@redhat.com>]

Makes x86 linux kernel find virtio-mmio devices automatically.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/i386/acpi-build.c | 51 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 0e45a646af56..80844db24d6b 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -21,6 +21,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qnum.h"
 #include "acpi-build.h"
@@ -60,6 +61,7 @@
 #include "hw/pci-host/q35.h"
 #include "hw/i386/x86-iommu.h"
 #include "hw/i386/microvm.h"
+#include "hw/virtio/virtio-mmio.h"
 
 #include "hw/acpi/aml-build.h"
 #include "hw/acpi/utils.h"
@@ -2750,6 +2752,54 @@ static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg)
     return true;
 }
 
+static void acpi_dsdt_add_virtio(Aml *scope)
+{
+    gchar *separator;
+    long int index;
+    BusState *bus;
+    BusChild *kid;
+
+    bus = sysbus_get_default();
+    QTAILQ_FOREACH(kid, &bus->children, sibling) {
+        DeviceState *dev = kid->child;
+        ObjectClass *class = object_get_class(OBJECT(dev));
+
+        if (class == object_class_by_name(TYPE_VIRTIO_MMIO)) {
+            VirtIOMMIOProxy *mmio = VIRTIO_MMIO(OBJECT(dev));
+            VirtioBusState *mmio_virtio_bus = &mmio->bus;
+            BusState *mmio_bus = &mmio_virtio_bus->parent_obj;
+
+            if (QTAILQ_EMPTY(&mmio_bus->children)) {
+                continue;
+            }
+            separator = g_strrstr(mmio_bus->name, ".");
+            if (!separator) {
+                continue;
+            }
+            if (qemu_strtol(separator + 1, NULL, 10, &index) != 0) {
+                continue;
+            }
+
+            uint32_t irq = VIRTIO_IRQ_BASE + index;
+            hwaddr base = VIRTIO_MMIO_BASE + index * 512;
+            hwaddr size = 512;
+
+            Aml *dev = aml_device("VR%02u", (unsigned)index);
+            aml_append(dev, aml_name_decl("_HID", aml_string("LNRO0005")));
+            aml_append(dev, aml_name_decl("_UID", aml_int(index)));
+            aml_append(dev, aml_name_decl("_CCA", aml_int(1)));
+
+            Aml *crs = aml_resource_template();
+            aml_append(crs, aml_memory32_fixed(base, size, AML_READ_WRITE));
+            aml_append(crs,
+                       aml_interrupt(AML_CONSUMER, AML_LEVEL, AML_ACTIVE_HIGH,
+                                     AML_EXCLUSIVE, &irq, 1));
+            aml_append(dev, aml_name_decl("_CRS", crs));
+            aml_append(scope, dev);
+        }
+    }
+}
+
 static void
 build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
                    MicrovmMachineState *mms)
@@ -2766,6 +2816,7 @@ build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
 
     sb_scope = aml_scope("_SB");
     acpi_dsdt_add_fw_cfg(sb_scope, OBJECT(x86ms->fw_cfg));
+    acpi_dsdt_add_virtio(sb_scope);
     aml_append(dsdt, sb_scope);
 
     scope = aml_scope("\\");
-- 
2.18.2