[PATCH v4 01/15] hw/pci: Add a pci_setup_iommu_ops() helper

[Joao Martins]

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

Add a pci_setup_iommu_ops() that uses a newly added structure
(PCIIOMMUOps) instead of using PCIIOMMUFunc. The old pci_setup_iommu()
that uses PCIIOMMUFunc is still kept for other IOMMUs to get an
an address space for a PCI device in vendor specific way.

In preparation to expand to supplying vIOMMU attributes, add a
alternate helper pci_setup_iommu_ops() to setup the PCI device IOMMU.
For now the PCIIOMMUOps just defines the address_space, but it will
be extended to have another callback.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
[joao: Massage commit message and subject, and make it a complementary
rather than changing every single consumer of pci_setup_iommu()]
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
v1: https://lore.kernel.org/all/20210302203827.437645-5-yi.l.liu@intel.com/
---
 include/hw/pci/pci.h     |  7 +++++++
 include/hw/pci/pci_bus.h |  1 +
 hw/pci/pci.c             | 26 +++++++++++++++++++++++---
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index e6d0574a2999..f59aef5a329a 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -368,6 +368,13 @@ typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, 
int);
 AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
 void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
 
+typedef struct PCIIOMMUOps PCIIOMMUOps;
+struct PCIIOMMUOps {
+    AddressSpace * (*get_address_space)(PCIBus *bus,
+                                void *opaque, int32_t devfn);
+};
+void pci_setup_iommu_ops(PCIBus *bus, const PCIIOMMUOps *iommu_ops, void 
*opaque);
+
 pcibus_t pci_bar_address(PCIDevice *d,
                          int reg, uint8_t type, pcibus_t size);
 
diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
index 56531759578f..fb770b236d69 100644
--- a/include/hw/pci/pci_bus.h
+++ b/include/hw/pci/pci_bus.h
@@ -35,6 +35,7 @@ struct PCIBus {
     enum PCIBusFlags flags;
     PCIIOMMUFunc iommu_fn;
     void *iommu_opaque;
+    const PCIIOMMUOps *iommu_ops;
     uint8_t devfn_min;
     uint32_t slot_reserved_mask;
     pci_set_irq_fn set_irq;
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bf38905b7dc0..4e32c09e81d6 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2639,7 +2639,15 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice 
*dev)
     PCIBus *iommu_bus = bus;
     uint8_t devfn = dev->devfn;
 
-    while (iommu_bus && !iommu_bus->iommu_fn && iommu_bus->parent_dev) {
+    /*
+     * get_address_space() callback is mandatory when iommu uses
+     * pci_setup_iommu_ops(), so needs to ensure its presence in
+     * the iommu_bus search.
+     */
+    while (iommu_bus &&
+           !(iommu_bus->iommu_fn ||
+            (iommu_bus->iommu_ops && iommu_bus->iommu_ops->get_address_space)) 
&&
+           iommu_bus->parent_dev) {
         PCIBus *parent_bus = pci_get_bus(iommu_bus->parent_dev);
 
         /*
@@ -2678,8 +2686,14 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice 
*dev)
 
         iommu_bus = parent_bus;
     }
-    if (!pci_bus_bypass_iommu(bus) && iommu_bus && iommu_bus->iommu_fn) {
-        return iommu_bus->iommu_fn(bus, iommu_bus->iommu_opaque, devfn);
+    if (!pci_bus_bypass_iommu(bus) && iommu_bus) {
+        if (iommu_bus->iommu_fn) {
+           return iommu_bus->iommu_fn(bus, iommu_bus->iommu_opaque, devfn);
+        } else if (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);
+        }
     }
     return &address_space_memory;
 }
@@ -2690,6 +2704,12 @@ void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void 
*opaque)
     bus->iommu_opaque = opaque;
 }
 
+void pci_setup_iommu_ops(PCIBus *bus, const PCIIOMMUOps *ops, void *opaque)
+{
+    bus->iommu_ops = ops;
+    bus->iommu_opaque = opaque;
+}
+
 static void pci_dev_get_w64(PCIBus *b, PCIDevice *dev, void *opaque)
 {
     Range *range = opaque;
-- 
2.17.2