[PATCH v8 6/9] virtio-iommu: Add an option to define the input range width

[Eric Auger <eric.auger@redhat.com>]

aw-bits is a new option that allows to set the bit width of
the input address range. This value will be used as a default for
the device config input_range.end. By default it is set to 64 bits
which is the current value.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>

---
v7 -> v8:
- add return when error [Phil]

v1 -> v2:
- Check the aw-bits value is within [32,64]
---
 include/hw/virtio/virtio-iommu.h | 1 +
 hw/virtio/virtio-iommu.c         | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h
index 67ea5022af..83a52cc446 100644
--- a/include/hw/virtio/virtio-iommu.h
+++ b/include/hw/virtio/virtio-iommu.h
@@ -68,6 +68,7 @@ struct VirtIOIOMMU {
     Notifier machine_done;
     bool granule_frozen;
     GranuleMode granule_mode;
+    uint8_t aw_bits;
 };
 
 #endif
diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index aab97e1527..1326c6ec41 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -1314,7 +1314,12 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp)
      * in vfio realize
      */
     s->config.bypass = s->boot_bypass;
-    s->config.input_range.end = UINT64_MAX;
+    if (s->aw_bits < 32 || s->aw_bits > 64) {
+        error_setg(errp, "aw-bits must be within [32,64]");
+        return;
+    }
+    s->config.input_range.end =
+        s->aw_bits == 64 ? UINT64_MAX : BIT_ULL(s->aw_bits) - 1;
 
     switch (s->granule_mode) {
     case GRANULE_MODE_4K:
@@ -1544,6 +1549,7 @@ static Property virtio_iommu_properties[] = {
     DEFINE_PROP_BOOL("boot-bypass", VirtIOIOMMU, boot_bypass, true),
     DEFINE_PROP_GRANULE_MODE("granule", VirtIOIOMMU, granule_mode,
                              GRANULE_MODE_HOST),
+    DEFINE_PROP_UINT8("aw-bits", VirtIOIOMMU, aw_bits, 64),
     DEFINE_PROP_END_OF_LIST(),
 };
 
-- 
2.41.0