Re: [kvmarm] [RFC PATCH 0/3] KVM: ARM: Get rid of hardcoded VGIC addresses

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-10-26 12:15, Paolo Bonzini wrote:
> Il 26/10/2012 12:09, Peter Maydell ha scritto:
>>>>
>>>> The other problem is configuring the redirection table.  If you need >64
>>>> sources you need ioctls like KVM_GET/SET_IRQCHIP_ONE_REG.
>> Why would you want an extra ONE_REG-like ioctl? The existing ONE_REG
>> ioctls have plenty of space in the ID range to allow you to devote
>> a subsection of it to your irqchip. (This is exactly how the ARM
>> VGIC save/load is going to work.)
> 
> Ok, I stand corrected. :)
> 
>> Whether you want to do startup configuration and board wiring via
>> the same ioctl that handles runtime state save/load/migration is
>> a different question, of course.
> 
> QEMU's MSI-X routing is not x86-specific, so it should use the same
> KVM_SET_GSI_ROUTING ioctl that x86 uses.

And it's not only MSI[-X]. Most IRQ sources need to be rounted, either
from userspace or from irqfd or from some other in-kernel source to a
specific IRQ controller. That allows to customize things according to a
specific board / SoC emulation.

Jan

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