hw/arm/virt: Write extra pci roots into fw_cfg

Add bus property to virt machine for primary PCI root bus and use it to add
extra pci roots behind it.

Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
Signed-off-by: Yubo Miao <miaoyubo@huawei.com>
Message-Id: <20201119014841.7298-4-cenjiahui@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/arm/virt.c

@@ -1289,7 +1289,8 @@ static void create_pcie(VirtMachineState *vms)
     }
 
     pci = PCI_HOST_BRIDGE(dev);
-    if (pci->bus) {
+    vms->bus = pci->bus;
+    if (vms->bus) {
         for (i = 0; i < nb_nics; i++) {
             NICInfo *nd = &nd_table[i];
 
@@ -1346,7 +1347,7 @@ static void create_pcie(VirtMachineState *vms)
 
         switch (vms->iommu) {
         case VIRT_IOMMU_SMMUV3:
-            create_smmu(vms, pci->bus);
+            create_smmu(vms, vms->bus);
             qemu_fdt_setprop_cells(vms->fdt, nodename, "iommu-map",
                                    0x0, vms->iommu_phandle, 0x0, 0x10000);
             break;
@@ -1481,6 +1482,8 @@ void virt_machine_done(Notifier *notifier, void *data)
         exit(1);
     }
 
+    fw_cfg_add_extra_pci_roots(vms->bus, vms->fw_cfg);
+
     virt_acpi_setup(vms);
     virt_build_smbios(vms);
 }

include/hw/arm/virt.h

@@ -163,6 +163,7 @@ struct VirtMachineState {
     DeviceState *gic;
     DeviceState *acpi_dev;
     Notifier powerdown_notifier;
+    PCIBus *bus;
 };
 
 #define VIRT_ECAM_ID(high) (high ? VIRT_HIGH_PCIE_ECAM : VIRT_PCIE_ECAM)