[RFC,v2,1/6] hw/pci/pci_host: Add iommu property for pci host

Commit Message

Wang Xingang March 24, 2021, 1:16 p.m. UTC

From: Xingang Wang <[e-mail]>

The pci host iommu property is useful to check whether
the iommu is enabled on the pci root bus.

Signed-off-by: Xingang Wang <[e-mail]>
Signed-off-by: Jiahui Cen <[e-mail]>
---
 hw/pci/pci.c              | 18 +++++++++++++++++-
 hw/pci/pci_host.c         |  2 ++
 include/hw/pci/pci.h      |  1 +
 include/hw/pci/pci_host.h |  1 +
 4 files changed, 21 insertions(+), 1 deletion(-)

Patch

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 0eadcdbc9e..b82f39af10 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -416,6 +416,22 @@  const char *pci_root_bus_path(PCIDevice *dev)
     return rootbus->qbus.name;
 }
 
+bool pci_root_bus_has_iommu(PCIBus *bus)
+{
+    PCIBus *rootbus = bus;
+    PCIHostState *host_bridge;
+
+    if (!pci_bus_is_root(bus)) {
+        rootbus = pci_device_root_bus(bus->parent_dev);
+    }
+
+    host_bridge = PCI_HOST_BRIDGE(rootbus->qbus.parent);
+
+    assert(host_bridge->bus == rootbus);
+
+    return host_bridge->iommu;
+}
+
 static void pci_root_bus_init(PCIBus *bus, DeviceState *parent,
                               MemoryRegion *address_space_mem,
                               MemoryRegion *address_space_io,
@@ -2715,7 +2731,7 @@  AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
 
         iommu_bus = parent_bus;
     }
-    if (iommu_bus && iommu_bus->iommu_fn) {
+    if (pci_root_bus_has_iommu(bus) && iommu_bus && iommu_bus->iommu_fn) {
         return iommu_bus->iommu_fn(bus, iommu_bus->iommu_opaque, devfn);
     }
     return &address_space_memory;
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index 8ca5fadcbd..92ce213b18 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -222,6 +222,8 @@  const VMStateDescription vmstate_pcihost = {
 static Property pci_host_properties_common[] = {
     DEFINE_PROP_BOOL("x-config-reg-migration-enabled", PCIHostState,
                      mig_enabled, true),
+    DEFINE_PROP_BOOL("pci-host-iommu-enabled", PCIHostState,
+                     iommu, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 1bc231480f..300332bc2c 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -479,6 +479,7 @@  void pci_for_each_bus(PCIBus *bus,
 
 PCIBus *pci_device_root_bus(const PCIDevice *d);
 const char *pci_root_bus_path(PCIDevice *dev);
+bool pci_root_bus_has_iommu(PCIBus *bus);
 PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn);
 int pci_qdev_find_device(const char *id, PCIDevice **pdev);
 void pci_bus_get_w64_range(PCIBus *bus, Range *range);
diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
index 52e038c019..64128e3a19 100644
--- a/include/hw/pci/pci_host.h
+++ b/include/hw/pci/pci_host.h
@@ -43,6 +43,7 @@  struct PCIHostState {
     uint32_t config_reg;
     bool mig_enabled;
     PCIBus *bus;
+    bool iommu;
 
     QLIST_ENTRY(PCIHostState) next;
 };