vfio/igd: Enable OpRegion by default

As the presence of OpRegion is used to detect IGD device now, and
guest driver usually depends on OpRegion to work. Enable OpRegion
on IGD devices by default for out-of-the-box passthrough experience
(except pre-boot display output), especially for libvirt users.

Example of IGD passthrough with libvirt:
<hostdev mode="subsystem" type="pci" managed="yes">
  <source>
    <address domain="0x0000" bus="0x00" slot="0x02" function="0x0"/>
  </source>
  <rom file="/path/to/igd/rom"/>
  <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x0"/>
 </hostdev>

Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Reviewed-by: Corvin Köhne <c.koehne@beckhoff.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250505170305.23622-7-tomitamoeko@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/docs/igd-assign.txt b/docs/igd-assign.txt
index 95beb7681279ca97fc2b4b390045847dcd59eabd..fc444503ff310a317d5d6724b4656c29c4a7dc87 100644 (file)
--- a/docs/igd-assign.txt
+++ b/docs/igd-assign.txt
@@ -102,7 +102,7 @@ digital formats work well.
 
 Options
 =======
-* x-igd-opregion=[on|*off*]
+* x-igd-opregion=[*on*|off]
   Copy host IGD OpRegion and expose it to guest with fw_cfg
 
 * x-igd-lpc=[on|*off*]
@@ -124,7 +124,7 @@ Examples
 
 * Adding IGD with OpRegion and LPC ID hack, but without VGA ranges
   (For UEFI guests)
-  -device vfio-pci,host=00:02.0,id=hostdev0,addr=2.0,x-igd-legacy-mode=off,x-igd-opregion=on,x-igd-lpc=on,romfile=efi_oprom.rom
+  -device vfio-pci,host=00:02.0,id=hostdev0,addr=2.0,x-igd-legacy-mode=off,x-igd-lpc=on,romfile=efi_oprom.rom
 
 
 Guest firmware

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 6908bcc0d3145c98d2999841d00451bdc51b6a3e..e1fab21b47adb4df9b011b3efb6d7c15c84bc8c2 100644 (file)
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3385,7 +3385,7 @@ static const Property vfio_pci_dev_properties[] = {
     DEFINE_PROP_BIT("x-req", VFIOPCIDevice, features,
                     VFIO_FEATURE_ENABLE_REQ_BIT, true),
     DEFINE_PROP_BIT("x-igd-opregion", VFIOPCIDevice, features,
-                    VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false),
+                    VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, true),
     DEFINE_PROP_BIT("x-igd-lpc", VFIOPCIDevice, features,
                     VFIO_FEATURE_ENABLE_IGD_LPC_BIT, false),
     DEFINE_PROP_ON_OFF_AUTO("x-igd-legacy-mode", VFIOPCIDevice,