intel-iommu: add Intel IOMMU emulation to q35 and add a machine option "iommu" as a switch

Add Intel IOMMU emulation to q35 chipset and expose it to the guest.
1. Add a machine option. Users can use "-machine iommu=on|off" in the command
line to enable/disable Intel IOMMU. The default is off.
2. Accroding to the machine option, q35 will initialize the Intel IOMMU and
use pci_setup_iommu() to setup q35_host_dma_iommu() as the IOMMU function for
the pci bus.
3. q35_host_dma_iommu() will return different address space according to the
bus_num and devfn of the device.

Signed-off-by: Le Tan <tamlokveer@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index 37f228e77e..721cf5bcd4 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -347,6 +347,48 @@ static void mch_reset(DeviceState *qdev)
     mch_update(mch);
 }
 
+static AddressSpace *q35_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
+{
+    IntelIOMMUState *s = opaque;
+    VTDAddressSpace **pvtd_as;
+    int bus_num = pci_bus_num(bus);
+
+    assert(0 <= bus_num && bus_num <= VTD_PCI_BUS_MAX);
+    assert(0 <= devfn && devfn <= VTD_PCI_DEVFN_MAX);
+
+    pvtd_as = s->address_spaces[bus_num];
+    if (!pvtd_as) {
+        /* No corresponding free() */
+        pvtd_as = g_malloc0(sizeof(VTDAddressSpace *) * VTD_PCI_DEVFN_MAX);
+        s->address_spaces[bus_num] = pvtd_as;
+    }
+    if (!pvtd_as[devfn]) {
+        pvtd_as[devfn] = g_malloc0(sizeof(VTDAddressSpace));
+
+        pvtd_as[devfn]->bus_num = (uint8_t)bus_num;
+        pvtd_as[devfn]->devfn = (uint8_t)devfn;
+        pvtd_as[devfn]->iommu_state = s;
+        memory_region_init_iommu(&pvtd_as[devfn]->iommu, OBJECT(s),
+                                 &s->iommu_ops, "intel_iommu", UINT64_MAX);
+        address_space_init(&pvtd_as[devfn]->as,
+                           &pvtd_as[devfn]->iommu, "intel_iommu");
+    }
+    return &pvtd_as[devfn]->as;
+}
+
+static void mch_init_dmar(MCHPCIState *mch)
+{
+    PCIBus *pci_bus = PCI_BUS(qdev_get_parent_bus(DEVICE(mch)));
+
+    mch->iommu = INTEL_IOMMU_DEVICE(qdev_create(NULL, TYPE_INTEL_IOMMU_DEVICE));
+    object_property_add_child(OBJECT(mch), "intel-iommu",
+                              OBJECT(mch->iommu), NULL);
+    qdev_init_nofail(DEVICE(mch->iommu));
+    sysbus_mmio_map(SYS_BUS_DEVICE(mch->iommu), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
+
+    pci_setup_iommu(pci_bus, q35_host_dma_iommu, mch->iommu);
+}
+
 static int mch_init(PCIDevice *d)
 {
     int i;
@@ -370,6 +412,10 @@ static int mch_init(PCIDevice *d)
                  &mch->pam_regions[i+1], PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE,
                  PAM_EXPAN_SIZE);
     }
+    /* Intel IOMMU (VT-d) */
+    if (qemu_opt_get_bool(qemu_get_machine_opts(), "iommu", false)) {
+        mch_init_dmar(mch);
+    }
     return 0;
 }