Re: [RFC XEN PATCH v4 5/5] libxl: Use gsi instead of irq for mapping pirq

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 5 Jan 2024, Jiqian Chen wrote:
> In PVH dom0, it uses the linux local interrupt mechanism,
> when it allocs irq for a gsi, it is dynamic, and follow
> the principle of applying first, distributing first. And
> the irq number is alloced from small to large, but the
> applying gsi number is not, may gsi 38 comes before gsi
> 28, that causes the irq number is not equal with the gsi
> number. And when passthrough a device, xl wants to use
> gsi to map pirq, see pci_add_dm_done->xc_physdev_map_pirq,
> but the gsi number is got from file
> /sys/bus/pci/devices/<sbdf>/irq in current code, so it
> will fail when mapping.
> 
> So, use real gsi number read from gsi sysfs.
> 
> Co-developed-by: Huang Rui <ray.huang@xxxxxxx>
> Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>