intel_iommu: Add support for translation for devices behind bridges

- Use a hash table indexed on bus pointers to store information about buses
  instead of using the bus numbers.
  Bus pointers are stored in a new VTDBus struct together with the vector
  of device address space pointers indexed by devfn.
- The bus number is still used for lookup for selective SID based invalidate,
  in which case the bus number is lazily resolved from the bus hash table and
  cached in a separate index.

Signed-off-by: Knut Omang <knut.omang@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 3 insertions, 22 deletions

diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index bd7409456f..c81507d710 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -426,31 +426,12 @@ static void mch_reset(DeviceState *qdev)
 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);
+    VTDAddressSpace *vtd_as;
 
-    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;
-        pvtd_as[devfn]->context_cache_entry.context_cache_gen = 0;
-        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;
+    vtd_as = vtd_find_add_as(s, bus, devfn);
+    return &vtd_as->as;
 }
 
 static void mch_init_dmar(MCHPCIState *mch)