Currently it is possible to attach several arm-smmuv3 devices to the
same bus although it is a wrong setup.
Change the prototype of pci_setup_iommu_per_bus to pass an error
handle. This latter is set when iommu_per_bus is already set and
used by the single caller (smmu_base_realize) to report a useful
error to the end-user.
While at it document pci_setup_iommu_per_bus callback in the header.
Fixes: 66d2f665e163 ("hw/arm/virt: Allow user-creatable SMMUv3 dev
instantiation")
Signed-off-by: Eric Auger <[email protected]>
Tested-by: Nathan Chen <[email protected]>
Reviewed-by: Shameer Kolothum <[email protected]>
Reviewed-by: Nicolin Chen <[email protected]>
---
v1 -> v2:
- in smmu_base_realize, return if pci_setup_iommu_per_bus returns false
(Philippe)
---
include/hw/pci/pci.h | 16 +++++++++++++++-
hw/arm/smmu-common.c | 4 +++-
hw/pci/pci.c | 9 +++++++--
3 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 5b179091de..f2448e941a 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -863,7 +863,21 @@ int pci_iommu_unregister_iotlb_notifier(PCIDevice *dev,
uint32_t pasid,
*/
void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *ops, void *opaque);
-void pci_setup_iommu_per_bus(PCIBus *bus, const PCIIOMMUOps *ops, void
*opaque);
+/**
+ * pci_setup_iommu_per_bus: Initialize specific IOMMU handlers for a PCIBus
+ *
+ * Similar to pci_setup_iommu but enforces that the iommu only protects
+ * @bus downstream end points and no other bus hierarchy
+ *
+ * @bus: the #PCIBus being updated.
+ * @ops: the #PCIIOMMUOps
+ * @opaque: passed to callbacks of the @ops structure.
+ * @errp: error handle
+ *
+ * Returns false on failure with @errp set, true on success
+ */
+bool pci_setup_iommu_per_bus(PCIBus *bus, const PCIIOMMUOps *ops,
+ void *opaque, Error **errp);
pcibus_t pci_bar_address(PCIDevice *d,
int reg, uint8_t type, pcibus_t size);
diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index 58c4452b1f..8e40ba603d 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -981,7 +981,9 @@ static void smmu_base_realize(DeviceState *dev, Error
**errp)
}
if (s->smmu_per_bus) {
- pci_setup_iommu_per_bus(pci_bus, s->iommu_ops, s);
+ if (!pci_setup_iommu_per_bus(pci_bus, s->iommu_ops, s, errp)) {
+ return;
+ }
} else {
pci_setup_iommu(pci_bus, s->iommu_ops, s);
}
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 4298adf5a0..6d54524c9b 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -3307,11 +3307,16 @@ void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps
*ops, void *opaque)
* IOMMU ops are returned, avoiding the use of the parent’s IOMMU when
* it's not appropriate.
*/
-void pci_setup_iommu_per_bus(PCIBus *bus, const PCIIOMMUOps *ops,
- void *opaque)
+bool pci_setup_iommu_per_bus(PCIBus *bus, const PCIIOMMUOps *ops,
+ void *opaque, Error **errp)
{
+ if (bus->iommu_per_bus) {
+ error_setg(errp, "An iommu is already attached to this bus");
+ return false;
+ }
pci_setup_iommu(bus, ops, opaque);
bus->iommu_per_bus = true;
+ return true;
}
static void pci_dev_get_w64(PCIBus *b, PCIDevice *dev, void *opaque)
--
2.53.0
