Commit cd4d7fb721 for qemu.org

commit cd4d7fb72109043d60b5cf6191a1678e96775b98
Author: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date:   Tue Jan 6 01:28:03 2026 -0500

    hw/pci: Introduce pci_device_get_host_iommu_quirks()

    In VFIO core, we call iommufd_backend_get_device_info() to return vendor
    specific hardware information data, but it's not good to retrieve this raw
    data in VFIO core.

    Introduce a new PCIIOMMUOps optional callback, get_host_iommu_quirk() which
    allows to retrieve the vendor specific hardware information data and convert
    it into bitmaps defined with enum host_iommu_quirks.

    pci_device_get_host_iommu_quirks() is a wrapper that can be called on a PCI
    device potentially protected by a vIOMMU.

    Suggested-by: Eric Auger <eric.auger@redhat.com>
    Suggested-by: Nicolin Chen <nicolinc@nvidia.com>
    Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
    Link: https://lore.kernel.org/qemu-devel/20260106062808.316574-2-zhenzhong.duan@intel.com
    Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index a136e772a3..8cbf5f5d70 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -3032,6 +3032,18 @@ uint64_t pci_device_get_viommu_flags(PCIDevice *dev)
     return 0;
 }

+uint64_t pci_device_get_host_iommu_quirks(PCIDevice *dev, uint32_t type,
+                                          void *caps, uint32_t size)
+{
+    PCIBus *iommu_bus;
+
+    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, NULL, NULL);
+    if (iommu_bus && iommu_bus->iommu_ops->get_host_iommu_quirks) {
+        return iommu_bus->iommu_ops->get_host_iommu_quirks(type, caps, size);
+    }
+    return 0;
+}
+
 int pci_pri_request_page(PCIDevice *dev, uint32_t pasid, bool priv_req,
                          bool exec_req, hwaddr addr, bool lpig,
                          uint16_t prgi, bool is_read, bool is_write)
diff --git a/include/hw/core/iommu.h b/include/hw/core/iommu.h
index fcbbcd1015..d5401a397b 100644
--- a/include/hw/core/iommu.h
+++ b/include/hw/core/iommu.h
@@ -22,4 +22,9 @@ enum viommu_flags {
     VIOMMU_FLAG_WANT_NESTING_PARENT = BIT_ULL(0),
 };

+/* Host IOMMU quirks. Extracted from host IOMMU capabilities */
+enum host_iommu_quirks {
+    HOST_IOMMU_QUIRK_NESTING_PARENT_BYPASS_RO = BIT_ULL(0),
+};
+
 #endif /* HW_IOMMU_H */
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 868817cc05..6fd8984c99 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -474,6 +474,23 @@ typedef struct PCIIOMMUOps {
      * enum viommu_flags.
      */
     uint64_t (*get_viommu_flags)(void *opaque);
+    /**
+     * @get_host_iommu_quirks: get host IOMMU quirks
+     *
+     * Optional callback, if not implemented, then vIOMMU doesn't support
+     * converting @type specific hardware information data into a standard
+     * bitmap format.
+     *
+     * @type: IOMMU hardware info type
+     *
+     * @caps: IOMMU @type specific hardware information data
+     *
+     * @size: size of @caps
+     *
+     * Returns: bitmap with each bit representing a host IOMMU quirk defined in
+     * enum host_iommu_quirks
+     */
+    uint64_t (*get_host_iommu_quirks)(uint32_t type, void *caps, uint32_t size);
     /**
      * @get_iotlb_info: get properties required to initialize a device IOTLB.
      *
@@ -666,6 +683,20 @@ void pci_device_unset_iommu_device(PCIDevice *dev);
  */
 uint64_t pci_device_get_viommu_flags(PCIDevice *dev);

+/**
+ * pci_device_get_host_iommu_quirks: get host IOMMU quirks.
+ *
+ * Returns: bitmap with each bit representing a host IOMMU quirk defined in
+ * enum host_iommu_quirks. Or 0 if vIOMMU doesn't convert any.
+ *
+ * @dev: PCI device pointer.
+ * @type: IOMMU hardware info type
+ * @caps: IOMMU @type specific hardware information data
+ * @size: size of @caps
+ */
+uint64_t pci_device_get_host_iommu_quirks(PCIDevice *dev, uint32_t type,
+                                          void *caps, uint32_t size);
+
 /**
  * pci_iommu_get_iotlb_info: get properties required to initialize a
  * device IOTLB.