hw/riscv/virt.c: add virtio-iommu-pci hotplug support

We want to add a RISC-V 'virt' libqos machine to increase our test
coverage. Some of the tests will try to plug a virtio-iommu-pci
device into the board and do some tests with it.

Enable virtio-iommu-pci in the 'virt' machine.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240217192607.32565-5-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

hw/riscv/virt.c

@@ -53,6 +53,7 @@
 #include "hw/display/ramfb.h"
 #include "hw/acpi/aml-build.h"
 #include "qapi/qapi-visit-common.h"
+#include "hw/virtio/virtio-iommu.h"
 
 /* KVM AIA only supports APLIC MSI. APLIC Wired is always emulated by QEMU. */
 static bool virt_use_kvm_aia(RISCVVirtState *s)
@@ -971,6 +972,34 @@ static void create_fdt_fw_cfg(RISCVVirtState *s, const MemMapEntry *memmap)
     qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0);
 }
 
+static void create_fdt_virtio_iommu(RISCVVirtState *s, uint16_t bdf)
+{
+    const char compat[] = "virtio,pci-iommu\0pci1af4,1057";
+    void *fdt = MACHINE(s)->fdt;
+    uint32_t iommu_phandle;
+    g_autofree char *iommu_node = NULL;
+    g_autofree char *pci_node = NULL;
+
+    pci_node = g_strdup_printf("/soc/pci@%lx",
+                               (long) virt_memmap[VIRT_PCIE_ECAM].base);
+    iommu_node = g_strdup_printf("%s/virtio_iommu@%x,%x", pci_node,
+                                 PCI_SLOT(bdf), PCI_FUNC(bdf));
+    iommu_phandle = qemu_fdt_alloc_phandle(fdt);
+
+    qemu_fdt_add_subnode(fdt, iommu_node);
+
+    qemu_fdt_setprop(fdt, iommu_node, "compatible", compat, sizeof(compat));
+    qemu_fdt_setprop_sized_cells(fdt, iommu_node, "reg",
+                                 1, bdf << 8, 1, 0, 1, 0,
+                                 1, 0, 1, 0);
+    qemu_fdt_setprop_cell(fdt, iommu_node, "#iommu-cells", 1);
+    qemu_fdt_setprop_cell(fdt, iommu_node, "phandle", iommu_phandle);
+
+    qemu_fdt_setprop_cells(fdt, pci_node, "iommu-map",
+                           0, iommu_phandle, 0, bdf,
+                           bdf + 1, iommu_phandle, bdf + 1, 0xffff - bdf);
+}
+
 static void finalize_fdt(RISCVVirtState *s)
 {
     uint32_t phandle = 1, irq_mmio_phandle = 1, msi_pcie_phandle = 1;
@@ -1680,7 +1709,8 @@ static HotplugHandler *virt_machine_get_hotplug_handler(MachineState *machine,
 {
     MachineClass *mc = MACHINE_GET_CLASS(machine);
 
-    if (device_is_dynamic_sysbus(mc, dev)) {
+    if (device_is_dynamic_sysbus(mc, dev) ||
+        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
         return HOTPLUG_HANDLER(machine);
     }
     return NULL;
@@ -1699,6 +1729,10 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
                                      SYS_BUS_DEVICE(dev));
         }
     }
+
+    if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
+        create_fdt_virtio_iommu(s, pci_get_bdf(PCI_DEVICE(dev)));
+    }
 }
 
 static void virt_machine_class_init(ObjectClass *oc, void *data)