From: Nathan Chen <nathanc@nvidia.com>

Set the default oas value to auto. The default Output Address Size used
to be 44-bit, but we change it to match what the host IOMMU properties
report so that users do not have to introspect host IDR5 for the OAS.

Signed-off-by: Nathan Chen <nathanc@nvidia.com>
---
 hw/arm/smmuv3.c   | 4 ++--
 hw/core/machine.c | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 0ab6d1e762..7d537b7947 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -2155,7 +2155,7 @@ static const Property smmuv3_properties[] = {
     /* RIL can be turned off for accel cases */
     DEFINE_PROP_ON_OFF_AUTO("ril", SMMUv3State, ril, ON_OFF_AUTO_AUTO),
     DEFINE_PROP_ON_OFF_AUTO("ats", SMMUv3State, ats, ON_OFF_AUTO_AUTO),
-    DEFINE_PROP_OAS_MODE("oas", SMMUv3State, oas, OAS_MODE_44),
+    DEFINE_PROP_OAS_MODE("oas", SMMUv3State, oas, OAS_MODE_AUTO),
     DEFINE_PROP_SSIDSIZE_MODE("ssidsize", SMMUv3State, ssidsize,
                               SSID_SIZE_MODE_AUTO),
 };
@@ -2190,7 +2190,7 @@ static void smmuv3_class_init(ObjectClass *klass, const void *data)
         "platform has ATS support before enabling this.");
     object_class_property_set_description(klass, "oas",
         "Specify Output Address Size (for accel=on). Supported values "
-        "are 44 or 48 bits. Defaults to 44 bits.");
+        "are 44 or 48 bits. Defaults to auto.");
     object_class_property_set_description(klass, "ssidsize",
         "Number of bits used to represent SubstreamIDs (SSIDs). "
         "A value of N allows SSIDs in the range [0 .. 2^N - 1]. "
diff --git a/hw/core/machine.c b/hw/core/machine.c
index aa208a2d9a..a668bb2ec3 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -43,6 +43,7 @@ GlobalProperty hw_compat_11_0[] = {
     { TYPE_ARM_SMMUV3, "ats", "off" },
     { TYPE_ARM_SMMUV3, "ril", "on" },
     { TYPE_ARM_SMMUV3, "ssidsize", "0" },
+    { TYPE_ARM_SMMUV3, "oas", "44" },
 };
 
 GlobalProperty hw_compat_10_2[] = {
-- 
2.43.0