Re: [PATCH 6/6] hw/vmapple: XHCI controller's interrupt mapping workaround for macOS

[Akihiko Odaki <akihiko.odaki@daynix.com>]

On 2024/12/09 4:16, Phil Dennis-Jordan wrote:
> This change enables the new conditional interrupt mapping support
> property on the vmapple machine type's integrated XHCI controller.
> The macOS guest driver attempts to use event rings 1 and 2 on the XHCI
> controller, despite there being only one (PCI pin) interrupt channel
> available. With conditional interrupt mapping enabled, the XHCI
> controller will only schedule events on interrupter 0 in PCI pin mode
> or when only a single MSI vector is active.

I think docs/system/arm/vmapple.rst also needs to be updated.

> 
> Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
> ---
>   hw/vmapple/vmapple.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/hw/vmapple/vmapple.c b/hw/vmapple/vmapple.c
> index f607981bc40..156ea33ae79 100644
> --- a/hw/vmapple/vmapple.c
> +++ b/hw/vmapple/vmapple.c
> @@ -453,6 +453,13 @@ static void create_pcie(VMAppleMachineState *vms)
>       }
>   
>       usb_controller = qdev_new(TYPE_QEMU_XHCI);
> +    /*
> +     * macOS XHCI driver attempts to schedule events onto even rings 1 & 2
> +     * even when (as here) there is no MSI-X support on this PCIe bus. Disabling
> +     * interrupter mapping in the XHCI controller works around the problem.
> +     */
> +    object_property_set_bool(OBJECT(usb_controller),
> +                             "conditional-intr-mapping", true, &error_fatal);

Use compat_props to change the global default for this machine.

By the way, this unconditionally adds xHCI and USB devices, but that 
should be avoided so that users can customize the configuration. Use 
defaults_enabled() as a condition.

Regards,
Akihiko Odaki

>       qdev_realize_and_unref(usb_controller, BUS(pci->bus), &error_fatal);
>   
>       usb_bus = USB_BUS(object_resolve_type_unambiguous(TYPE_USB_BUS,