[PATCH v2 05/10] vfio: Implement get_host_iommu_info() callback

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

Utilize iova_ranges to calculate host IOMMU address width and
package it in HIOD_LEGACY_INFO for vIOMMU usage.

HIOD_LEGACY_INFO will be used by both VFIO and VDPA so declare
it in host_iommu_device.h.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 include/sysemu/host_iommu_device.h | 10 ++++++++++
 hw/vfio/container.c                | 24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/include/sysemu/host_iommu_device.h b/include/sysemu/host_iommu_device.h
index 22ccbe3a5d..beb8be8231 100644
--- a/include/sysemu/host_iommu_device.h
+++ b/include/sysemu/host_iommu_device.h
@@ -16,4 +16,14 @@ struct HostIOMMUDeviceClass {
     int (*get_host_iommu_info)(HostIOMMUDevice *hiod, void *data, uint32_t len,
                                Error **errp);
 };
+
+/*
+ * Define the format of host IOMMU related info that current VFIO
+ * or VDPA can privode to vIOMMU.
+ *
+ * @aw_bits: Host IOMMU address width. 0xff if no limitation.
+ */
+typedef struct HIOD_LEGACY_INFO {
+    uint8_t aw_bits;
+} HIOD_LEGACY_INFO;
 #endif
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 44018ef085..ba0ad4a41b 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -1143,8 +1143,32 @@ static void vfio_iommu_legacy_class_init(ObjectClass *klass, void *data)
     vioc->pci_hot_reset = vfio_legacy_pci_hot_reset;
 };
 
+static int hiod_legacy_vfio_get_host_iommu_info(HostIOMMUDevice *hiod,
+                                                void *data, uint32_t len,
+                                                Error **errp)
+{
+    VFIODevice *vbasedev = HIOD_LEGACY_VFIO(hiod)->vdev;
+    /* iova_ranges is a sorted list */
+    GList *l = g_list_last(vbasedev->bcontainer->iova_ranges);
+    HIOD_LEGACY_INFO *info = data;
+
+    assert(sizeof(HIOD_LEGACY_INFO) <= len);
+
+    if (l) {
+        Range *range = l->data;
+        info->aw_bits = find_last_bit(&range->upb, BITS_PER_LONG) + 1;
+    } else {
+        info->aw_bits = 0xff;
+    }
+
+    return 0;
+}
+
 static void hiod_legacy_vfio_class_init(ObjectClass *oc, void *data)
 {
+    HostIOMMUDeviceClass *hioc = HOST_IOMMU_DEVICE_CLASS(oc);
+
+    hioc->get_host_iommu_info = hiod_legacy_vfio_get_host_iommu_info;
 };
 
 static const TypeInfo types[] = {
-- 
2.34.1