From: Liu Yi L <yi.l.liu@intel.com>

This patch adds pci_device_iommu_context() to get an iommu_context
for a given device. A new callback is added in PCIIOMMUOps. Users
who wants to call into vIOMMU could leaverage it. And further vIOMMU
operation could be done via IOMMUContext.

Note:
Previous version has got Reviewed by from David Gibson and Peter Xu.
But this version has slight changes due to the patch rebase. so I
didn't add reviewed by from you two in case of that you two want to
have one more review. If you two have no objection, I would add your
review by in next version. Thanks.

Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
---
 hw/pci/pci.c         | 35 ++++++++++++++++++++++++++++++-----
 include/hw/pci/pci.h |  5 +++++
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index e331a5c..d2cd810 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2638,7 +2638,8 @@ static void pci_device_class_base_init(ObjectClass *klass, void *data)
     }
 }
 
-AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
+static void pci_device_get_iommu_bus_devfn(PCIDevice *dev,
+                              PCIBus **pbus, uint8_t *pdevfn)
 {
     PCIBus *bus = pci_get_bus(dev);
     PCIBus *iommu_bus = bus;
@@ -2683,14 +2684,38 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
 
         iommu_bus = parent_bus;
     }
-    if (iommu_bus && iommu_bus->iommu_ops &&
-                     iommu_bus->iommu_ops->get_address_space) {
-        return iommu_bus->iommu_ops->get_address_space(bus,
-                                 iommu_bus->iommu_opaque, devfn);
+    *pbus = iommu_bus;
+    *pdevfn = devfn;
+}
+
+AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
+{
+    PCIBus *bus;
+    uint8_t devfn;
+
+    pci_device_get_iommu_bus_devfn(dev, &bus, &devfn);
+    if (bus && bus->iommu_ops &&
+                     bus->iommu_ops->get_address_space) {
+        return bus->iommu_ops->get_address_space(bus,
+                                bus->iommu_opaque, devfn);
     }
     return &address_space_memory;
 }
 
+IOMMUContext *pci_device_iommu_context(PCIDevice *dev)
+{
+    PCIBus *bus;
+    uint8_t devfn;
+
+    pci_device_get_iommu_bus_devfn(dev, &bus, &devfn);
+    if (bus && bus->iommu_ops &&
+                    bus->iommu_ops->get_iommu_context) {
+        return bus->iommu_ops->get_iommu_context(bus,
+                              bus->iommu_opaque, devfn);
+    }
+    return NULL;
+}
+
 void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *ops, void *opaque)
 {
     bus->iommu_ops = ops;
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index dc89aa1..43e2023 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -9,6 +9,8 @@
 
 #include "hw/pci/pcie.h"
 
+#include "hw/iommu/iommu_context.h"
+
 extern bool pci_available;
 
 /* PCI bus */
@@ -488,9 +490,12 @@ typedef struct PCIIOMMUOps PCIIOMMUOps;
 struct PCIIOMMUOps {
     AddressSpace * (*get_address_space)(PCIBus *bus,
                                 void *opaque, int32_t devfn);
+    IOMMUContext * (*get_iommu_context)(PCIBus *bus,
+                                void *opaque, int32_t devfn);
 };
 
 AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
+IOMMUContext *pci_device_iommu_context(PCIDevice *dev);
 void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *iommu_ops, void *opaque);
 
 static inline void
-- 
2.7.4