On Wed, 21 May 2025 23:40:36 +0800
Tomita Moeko <tomitamo...@gmail.com> wrote:
> In vfio_pci_igd_opregion_detect(), errp will be set when device does
> not have OpRegion or is hotplugged. This errp will be propergated to
propagated
> pci_qdev_realize(), which interprets it as failure, causing unexpected
> termination on devices without OpRegion like SR-IOV VFs or discrete
> GPUs. Fix it by not setting errp in vfio_pci_igd_opregion_detect().
>
> This patch also checks if the device has OpRegion before hotplug status
> to prvent unwanted warning messages on non-IGD devices.
>
> Fixes: c0273e77f2d7 ("vfio/igd: Detect IGD device by OpRegion")
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2968
> Reported-by: Edmund Raile <edmund.ra...@protonmail.com>
> Link:
> https://lore.kernel.org/qemu-devel/30044d14-17ec-46e3-b9c3-63d27a5bd...@gmail.com
> Signed-off-by: Tomita Moeko <tomitamo...@gmail.com>
> ---
> hw/vfio/igd.c | 22 ++++++++++------------
> 1 file changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
> index e7952d15a0..e7a9d1ffc1 100644
> --- a/hw/vfio/igd.c
> +++ b/hw/vfio/igd.c
> @@ -187,23 +187,21 @@ static bool vfio_pci_igd_opregion_init(VFIOPCIDevice
> *vdev,
> }
>
> static bool vfio_pci_igd_opregion_detect(VFIOPCIDevice *vdev,
> - struct vfio_region_info **opregion,
> - Error **errp)
> + struct vfio_region_info **opregion)
> {
> int ret;
>
> - /* Hotplugging is not supported for opregion access */
> - if (vdev->pdev.qdev.hotplugged) {
> - error_setg(errp, "IGD OpRegion is not supported on hotplugged
> device");
> - return false;
> - }
> -
> ret = vfio_device_get_region_info_type(&vdev->vbasedev,
> VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
> VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, opregion);
> if (ret) {
> - error_setg_errno(errp, -ret,
> - "Device does not supports IGD OpRegion feature");
> + return false;
> + }
> +
> + /* Hotplugging is not supported for opregion access */
> + if (vdev->pdev.qdev.hotplugged) {
> + warn_report("IGD device detected, but OpRegion is not supported "
> + "on hotplugged device.");
> return false;
> }
>
> @@ -524,7 +522,7 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice
> *vdev, Error **errp)
> }
>
> /* IGD device always comes with OpRegion */
> - if (!vfio_pci_igd_opregion_detect(vdev, &opregion, errp)) {
> + if (!vfio_pci_igd_opregion_detect(vdev, &opregion)) {
> return true;
> }
> info_report("OpRegion detected on Intel display %x.", vdev->device_id);
> @@ -695,7 +693,7 @@ static bool vfio_pci_kvmgt_config_quirk(VFIOPCIDevice
> *vdev, Error **errp)
> return true;
> }
>
> - if (!vfio_pci_igd_opregion_detect(vdev, &opregion, errp)) {
> + if (!vfio_pci_igd_opregion_detect(vdev, &opregion)) {
> /* Should never reach here, KVMGT always emulates OpRegion */
> return false;
> }
