Re: [PATCH] hw/i386/pc_piix: Make piix_intx_routing_notifier_xen() more device independent

[David Woodhouse <dwmw2@infradead.org>]

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On Mon, 2024-01-08 at 00:16 +0100, Bernhard Beschow wrote:
> This is a follow-up on commit 89965db43cce "hw/isa/piix3: Avoid Xen-specific
> variant of piix3_write_config()" which introduced
> piix_intx_routing_notifier_xen(). This function is implemented in board code but
> accesses the PCI configuration space of the PIIX ISA function to determine the
> PCI interrupt routes. Avoid this by reusing pci_device_route_intx_to_irq() which
> makes piix_intx_routing_notifier_xen() more device-agnostic.
> 
> One remaining improvement would be making piix_intx_routing_notifier_xen()
> agnostic towards the number of PCI interrupt routes and move it to xen-hvm.
> This might be useful for possible Q35 Xen efforts but remains a future exercise
> for now.
> 
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>

I'm still moderately unhappy that all this code is written with the
apparent assumption that there is only *one* IRQ# which is the target
for a given INTx, when in fact it gets routed to that pin# on the
legacy PIC and a potentially *different* pin# on the I/O APIC.

But you aren't making that worse, so

Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>

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