pci: Add an API to get IOMMU's min page size and virtual address width
This kind of information is needed by devices implementing ATS in order
to initialize their translation cache.
Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>
Message-Id: <20250520071823.764266-8-clement.mathieu--drif@eviden.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 1114ba8..fc4954a 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2970,6 +2970,23 @@
}
}
+int pci_iommu_get_iotlb_info(PCIDevice *dev, uint8_t *addr_width,
+ uint32_t *min_page_size)
+{
+ PCIBus *bus;
+ PCIBus *iommu_bus;
+ int devfn;
+
+ pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
+ if (iommu_bus && iommu_bus->iommu_ops->get_iotlb_info) {
+ iommu_bus->iommu_ops->get_iotlb_info(iommu_bus->iommu_opaque,
+ addr_width, min_page_size);
+ return 0;
+ }
+
+ return -ENODEV;
+}
+
void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *ops, void *opaque)
{
/*
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index c2fe6ca..d67ffe1 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -429,6 +429,19 @@
* @devfn: device and function number of the PCI device.
*/
void (*unset_iommu_device)(PCIBus *bus, void *opaque, int devfn);
+ /**
+ * @get_iotlb_info: get properties required to initialize a device IOTLB.
+ *
+ * Callback required if devices are allowed to cache translations.
+ *
+ * @opaque: the data passed to pci_setup_iommu().
+ *
+ * @addr_width: the address width of the IOMMU (output parameter).
+ *
+ * @min_page_size: the page size of the IOMMU (output parameter).
+ */
+ void (*get_iotlb_info)(void *opaque, uint8_t *addr_width,
+ uint32_t *min_page_size);
} PCIIOMMUOps;
AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
@@ -437,6 +450,19 @@
void pci_device_unset_iommu_device(PCIDevice *dev);
/**
+ * pci_iommu_get_iotlb_info: get properties required to initialize a
+ * device IOTLB.
+ *
+ * Returns 0 on success, or a negative errno otherwise.
+ *
+ * @dev: the device that wants to get the information.
+ * @addr_width: the address width of the IOMMU (output parameter).
+ * @min_page_size: the page size of the IOMMU (output parameter).
+ */
+int pci_iommu_get_iotlb_info(PCIDevice *dev, uint8_t *addr_width,
+ uint32_t *min_page_size);
+
+/**
* pci_setup_iommu: Initialize specific IOMMU handlers for a PCIBus
*
* Let PCI host bridges define specific operations.
