On 5/24/25 23:31, Tomita Moeko wrote:
> Introduce x-pci-class-code option to allow users to override PCI class
> code of a device, similar to the existing x-pci-vendor-id option. Only
> the lower 24 bits of this option are used, though a uint32 is used here
> for determining whether the value is valid and set by user.
>
> This is mainly intended for IGD devices that expose themselves either
> as VGA controller (primary display) or Display controller (non-primary
> display). The UEFI GOP driver depends on the device reporting a VGA
> controller class code (0x030000).
>
> Signed-off-by: Tomita Moeko <tomitamo...@gmail.com>
> ---
> hw/vfio/pci.c | 17 +++++++++++++++++
> hw/vfio/pci.h | 1 +
> hw/vfio/trace-events | 1 +
> 3 files changed, 19 insertions(+)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index a1bfdfe375..879347a54e 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3062,6 +3062,21 @@ static bool vfio_pci_config_setup(VFIOPCIDevice *vdev,
> Error **errp)
> vdev->sub_device_id);
> }
>
> + /*
> + * Class code is a 24-bit value at config space 0x09. Allow overriding it
> + * with any 24-bit value.
> + */
> + if (vdev->class_code != PCI_ANY_ID) {
> + if (vdev->class_code > 0xffffff) {
> + error_setg(errp, "invalid PCI class code provided");
> + return false;
> + }
> + /* Higher 24 bits of PCI_CLASS_REVISION are class code */
> + vfio_add_emulated_long(vdev, PCI_CLASS_REVISION,
> + vdev->class_code << 8, ~0xff);
> + trace_vfio_pci_emulated_class_code(vbasedev->name, vdev->class_code);
> + }
> +
> /* QEMU can change multi-function devices to single function, or reverse
> */
> vdev->emulated_config_bits[PCI_HEADER_TYPE] =
> PCI_HEADER_TYPE_MULTI_FUNCTION;
> @@ -3482,6 +3497,8 @@ static const Property vfio_pci_dev_properties[] = {
> sub_vendor_id, PCI_ANY_ID),
> DEFINE_PROP_UINT32("x-pci-sub-device-id", VFIOPCIDevice,
> sub_device_id, PCI_ANY_ID),
> + DEFINE_PROP_UINT32("x-pci-class-code", VFIOPCIDevice,
> + class_code, PCI_ANY_ID),
> DEFINE_PROP_UINT32("x-igd-gms", VFIOPCIDevice, igd_gms, 0),
> DEFINE_PROP_UNSIGNED_NODEFAULT("x-nv-gpudirect-clique", VFIOPCIDevice,
> nv_gpudirect_clique,
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index 5ce0fb916f..587eb8cc9a 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -156,6 +156,7 @@ struct VFIOPCIDevice {
> uint32_t device_id;
> uint32_t sub_vendor_id;
> uint32_t sub_device_id;
> + uint32_t class_code;
> uint32_t features;
> #define VFIO_FEATURE_ENABLE_VGA_BIT 0
> #define VFIO_FEATURE_ENABLE_VGA (1 << VFIO_FEATURE_ENABLE_VGA_BIT)
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index e90ec9bff8..d0b006aa29 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -46,6 +46,7 @@ vfio_pci_emulated_vendor_id(const char *name, uint16_t val)
> "%s 0x%04x"
> vfio_pci_emulated_device_id(const char *name, uint16_t val) "%s 0x%04x"
> vfio_pci_emulated_sub_vendor_id(const char *name, uint16_t val) "%s 0x%04x"
> vfio_pci_emulated_sub_device_id(const char *name, uint16_t val) "%s 0x%04x"
> +vfio_pci_emulated_class_code(const char *name, uint16_t val) "%s 0x%06x"
^^^^^^^^
Sorry there is a mistake, it should be `uint32_t` here...
> # pci-quirks.c
> vfio_quirk_rom_in_denylist(const char *name, uint16_t vid, uint16_t did) "%s
> %04x:%04x"
