hw/i386/intel_iommu: Do not use SysBus API to map local MMIO region

There is no point in exposing an internal MMIO region via
SysBus and directly mapping it in the very same device.

Just map it without using the SysBus API.

Transformation done using the following coccinelle script:

  @@
  expression sbdev;
  expression index;
  expression addr;
  expression subregion;
  @@
  -    sysbus_init_mmio(sbdev, subregion);
       ... when != sbdev
  -    sysbus_mmio_map(sbdev, index, addr);
  +    memory_region_add_subregion(get_system_memory(), addr, subregion);

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20231018141151.87466-3-philmd@linaro.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 2c832ab..e4f6ced 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -4134,6 +4134,8 @@ static void vtd_realize(DeviceState *dev, Error **errp)
     qemu_mutex_init(&s->iommu_lock);
     memory_region_init_io(&s->csrmem, OBJECT(s), &vtd_mem_ops, s,
                           "intel_iommu", DMAR_REG_SIZE);
+    memory_region_add_subregion(get_system_memory(),
+                                Q35_HOST_BRIDGE_IOMMU_ADDR, &s->csrmem);
 
     /* Create the shared memory regions by all devices */
     memory_region_init(&s->mr_nodmar, OBJECT(s), "vtd-nodmar",
@@ -4148,15 +4150,12 @@ static void vtd_realize(DeviceState *dev, Error **errp)
     memory_region_add_subregion_overlap(&s->mr_nodmar,
                                         VTD_INTERRUPT_ADDR_FIRST,
                                         &s->mr_ir, 1);
-
-    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->csrmem);
     /* No corresponding destroy */
     s->iotlb = g_hash_table_new_full(vtd_iotlb_hash, vtd_iotlb_equal,
                                      g_free, g_free);
     s->vtd_address_spaces = g_hash_table_new_full(vtd_as_hash, vtd_as_equal,
                                       g_free, g_free);
     vtd_init(s);
-    sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
     pci_setup_iommu(bus, vtd_host_dma_iommu, dev);
     /* Pseudo address space under root PCI bus. */
     x86ms->ioapic_as = vtd_host_dma_iommu(bus, s, Q35_PSEUDO_DEVFN_IOAPIC);