Re: [PATCH 0/3] hw/boards: Remove MachineState::usb_disabled field

[Paolo Bonzini <pbonzini@redhat.com>]

On 5/26/25 16:20, Philippe Mathieu-Daudé wrote:
> On 26/5/25 15:18, BALATON Zoltan wrote:
>> On Mon, 26 May 2025, Philippe Mathieu-Daudé wrote:
>>> Only add default devices checking defaults_enabled().
>>> Remove the unused usb_disabled field in MachineState.
>>
>> At least for Mac machines this may be more complex. I think there is a 
>> - usb switch to enable/disable USB independently of defaults and due 
>> to some bugs some MacOS versions may need this to boot so maybe it's 
>> used.
> 
> If the user asks -usb off, we shouldn't re-enable it in the shadow.

And if the user asks -usb on, you shouldn't disable it.  My
understanding is that adding

-        if (!has_adb || machine_arch == ARCH_MAC99_U3) {
+        if ((!has_adb || machine_arch == ARCH_MAC99_U3) && defaults_enabled()) {

disables USB completely when -nodefaults.

If you want to remove usb_disabled, change machine->usb to ON_OFF_AUTO
and query

static inline bool machine_usb_enabled(MachineState *ms)
{
         return (defaults_enabled()
                 ? machine->usb != ON_OFF_AUTO_OFF
                 : machine->usb == ON_OFF_AUTO_ON);
}

instead of machine->usb (even better, change the name of the field so that
it causes a compilation error).

Paolo