hw/i386/pc: Move IOMMU singleton into PCMachineState

We're about to support a third vIOMMU for x86, virtio-iommu which
doesn't inherit X86IOMMUState. Move the IOMMU singleton into
PCMachineState, so it can be shared between all three vIOMMUs.

The x86_iommu_get_default() helper is still needed by KVM and IOAPIC to
fetch the default IRQ-remapping IOMMU. Since virtio-iommu doesn't
support IRQ remapping, this interface doesn't need to change for the
moment. We could later replace X86IOMMUState with an "IRQ remapping
IOMMU" interface if necessary.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Message-Id: <20211026182024.2642038-4-jean-philippe@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 86223acfd3..7b1c4f41cd 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1330,6 +1330,15 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
                object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
         pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE)) {
+        PCMachineState *pcms = PC_MACHINE(hotplug_dev);
+
+        if (pcms->iommu) {
+            error_setg(errp, "QEMU does not support multiple vIOMMUs "
+                       "for x86 yet.");
+            return;
+        }
+        pcms->iommu = dev;
     }
 }
 
@@ -1384,7 +1393,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
         object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
         object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
-        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) ||
+        object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE)) {
         return HOTPLUG_HANDLER(machine);
     }