Re: [Qemu-devel] RFC: ioapic polarity vs. qemu os-x guest

[Alexander Graf]

On 14.02.2014, at 23:06, Gabriel L. Somlo <address@hidden> wrote:

> On Fri, Feb 14, 2014 at 10:21:09PM +0100, Alexander Graf wrote:
>> 
>> Can't you just turn the polarity around in the pci host adapter?
> 
> I tried this:
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 1221f32..0e86d21 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -118,13 +118,13 @@ static int pci_bar(PCIDevice *d, int reg)
> 
> static inline int pci_irq_state(PCIDevice *d, int irq_num)
> {
> -     return (d->irq_state >> irq_num) & 0x1;
> +     return !(d->irq_state >> irq_num) & 0x1;
> }
> 
> static inline void pci_set_irq_state(PCIDevice *d, int irq_num, int level)
> {
>       d->irq_state &= ~(0x1 << irq_num);
> -     d->irq_state |= level << irq_num;
> +     d->irq_state &= ~(level << irq_num);
> }
> 
> static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change)
> @@ -229,7 +229,7 @@ static void pcibus_reset(BusState *qbus)
>     }
> 
>     for (i = 0; i < bus->nirq; i++) {
> -        assert(bus->irq_count[i] == 0);
> +        assert(bus->irq_count[i] != 0);
>     }
> }
> 
> ---
> 
> but now OS X freezes during boot right after
> 
>       [ PCI configuration begin ]
>       [ PCI configuration end, bridges 1, devices 10 ]
>       RTC: Only single RAM bank (128 bytes)
> 
> which all looks normal, except the process is supposed to continue on
> from there and doesn't :)
> 
> On Linux, I get Fedora 20 live all the way up with no obvious/loud
> complaints, but mouse and keyboard don't work at all...
> 
> I have to admit I'm a bit out of my depth here, though :)

Yeah, another thing we have to take into account is vhost-net which generates 
IRQs directly through irqfd. I guess for those we'll have to configure the 
polarity in the irq routing table?


Alex