[PATCH v2 09/10] hw/pci: Introduce pci_device_set/unset_iommu_device()

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

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

This adds pci_device_set/unset_iommu_device() to set/unset
HostIOMMUDevice for a given PCI device. Caller of set
should fail if set operation fails.

Extract out pci_device_get_iommu_bus_devfn() to facilitate
implementation of pci_device_set/unset_iommu_device().

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 include/hw/pci/pci.h | 40 ++++++++++++++++++++++-
 hw/pci/pci.c         | 75 ++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 111 insertions(+), 4 deletions(-)

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index eaa3fc99d8..4ae7fe6f3f 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -3,6 +3,7 @@
 
 #include "exec/memory.h"
 #include "sysemu/dma.h"
+#include "sysemu/host_iommu_device.h"
 
 /* PCI includes legacy ISA access.  */
 #include "hw/isa/isa.h"
@@ -383,10 +384,47 @@ typedef struct PCIIOMMUOps {
      *
      * @devfn: device and function number
      */
-   AddressSpace * (*get_address_space)(PCIBus *bus, void *opaque, int devfn);
+    AddressSpace * (*get_address_space)(PCIBus *bus, void *opaque, int devfn);
+    /**
+     * @set_iommu_device: attach a HostIOMMUDevice to a vIOMMU
+     *
+     * Optional callback, if not implemented in vIOMMU, then vIOMMU can't
+     * retrieve host information from the associated HostIOMMUDevice.
+     *
+     * Return true if HostIOMMUDevice is attached, or else return false
+     * with errp set.
+     *
+     * @bus: the #PCIBus of the PCI device.
+     *
+     * @opaque: the data passed to pci_setup_iommu().
+     *
+     * @devfn: device and function number of the PCI device.
+     *
+     * @dev: the data structure representing host IOMMU device.
+     *
+     * @errp: pass an Error out only when return false
+     *
+     */
+    int (*set_iommu_device)(PCIBus *bus, void *opaque, int devfn,
+                            HostIOMMUDevice *dev, Error **errp);
+    /**
+     * @unset_iommu_device: detach a HostIOMMUDevice from a vIOMMU
+     *
+     * Optional callback.
+     *
+     * @bus: the #PCIBus of the PCI device.
+     *
+     * @opaque: the data passed to pci_setup_iommu().
+     *
+     * @devfn: device and function number of the PCI device.
+     */
+    void (*unset_iommu_device)(PCIBus *bus, void *opaque, int devfn);
 } PCIIOMMUOps;
 
 AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
+int pci_device_set_iommu_device(PCIDevice *dev, HostIOMMUDevice *hiod,
+                                Error **errp);
+void pci_device_unset_iommu_device(PCIDevice *dev);
 
 /**
  * pci_setup_iommu: Initialize specific IOMMU handlers for a PCIBus
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index e7a39cb203..8ece617673 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2648,11 +2648,27 @@ static void pci_device_class_base_init(ObjectClass *klass, void *data)
     }
 }
 
-AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
+/*
+ * Get IOMMU root bus, aliased bus and devfn of a PCI device
+ *
+ * IOMMU root bus is needed by all call sites to call into iommu_ops.
+ * For call sites which don't need aliased BDF, passing NULL to
+ * aliased_[bus/devfn] is allowed.
+ *
+ * @piommu_bus: return root #PCIBus backed by an IOMMU for the PCI device.
+ *
+ * @aliased_bus: return aliased #PCIBus of the PCI device, optional.
+ *
+ * @aliased_devfn: return aliased devfn of the PCI device, optional.
+ */
+static void pci_device_get_iommu_bus_devfn(PCIDevice *dev,
+                                           PCIBus **piommu_bus,
+                                           PCIBus **aliased_bus,
+                                           int *aliased_devfn)
 {
     PCIBus *bus = pci_get_bus(dev);
     PCIBus *iommu_bus = bus;
-    uint8_t devfn = dev->devfn;
+    int devfn = dev->devfn;
 
     while (iommu_bus && !iommu_bus->iommu_ops && iommu_bus->parent_dev) {
         PCIBus *parent_bus = pci_get_bus(iommu_bus->parent_dev);
@@ -2693,13 +2709,66 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
 
         iommu_bus = parent_bus;
     }
-    if (!pci_bus_bypass_iommu(bus) && iommu_bus->iommu_ops) {
+
+    assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+    assert(iommu_bus);
+
+    if (pci_bus_bypass_iommu(bus) || !iommu_bus->iommu_ops) {
+        iommu_bus = NULL;
+    }
+
+    *piommu_bus = iommu_bus;
+
+    if (aliased_bus) {
+        *aliased_bus = bus;
+    }
+
+    if (aliased_devfn) {
+        *aliased_devfn = devfn;
+    }
+}
+
+AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
+{
+    PCIBus *bus;
+    PCIBus *iommu_bus;
+    int devfn;
+
+    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
+    if (iommu_bus) {
         return iommu_bus->iommu_ops->get_address_space(bus,
                                  iommu_bus->iommu_opaque, devfn);
     }
     return &address_space_memory;
 }
 
+int pci_device_set_iommu_device(PCIDevice *dev, HostIOMMUDevice *hiod,
+                                Error **errp)
+{
+    PCIBus *iommu_bus;
+
+    /* set_iommu_device requires device's direct BDF instead of aliased BDF */
+    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, NULL, NULL);
+    if (iommu_bus && iommu_bus->iommu_ops->set_iommu_device) {
+        return iommu_bus->iommu_ops->set_iommu_device(pci_get_bus(dev),
+                                                      iommu_bus->iommu_opaque,
+                                                      dev->devfn, hiod, errp);
+    }
+    return 0;
+}
+
+void pci_device_unset_iommu_device(PCIDevice *dev)
+{
+    PCIBus *iommu_bus;
+
+    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, NULL, NULL);
+    if (iommu_bus && iommu_bus->iommu_ops->unset_iommu_device) {
+        return iommu_bus->iommu_ops->unset_iommu_device(pci_get_bus(dev),
+                                                        iommu_bus->iommu_opaque,
+                                                        dev->devfn);
+    }
+}
+
 void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *ops, void *opaque)
 {
     /*
-- 
2.34.1