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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Sat, 22 Jun 2013 07:54:47 +1000
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Subject: Re: [Qemu-devel] [PATCH 2/3] KVM: add kvm_arch_irqchip_add_msi_route
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To: Alexander Graf <agraf@suse.de>
Cc: Anthony Liguori <aliguori@us.ibm.com>, Alexey Kardashevskiy <aik@ozlabs.ru>, qemu-devel@nongnu.org, Alex Williamson <alex.williamson@redhat.com>, qemu-ppc@nongnu.org, David Gibson <david@gibson.dropbear.id.au>

On Fri, 2013-06-21 at 15:46 +0200, Alexander Graf wrote:
> Not sure. We could just declare a "direct virq==irq" mode in which
> msi.data == virq == irq. No need for any translation then.

Maybe. Beware that MSI data is only 16-bit on the wire but we may not
care here.

One thing I'm not 100% certain of is how Alexey makes all that work with
VFIO since the MSI address/data in the device shall not be the qemu
"cooked up" ones, but the real HW ones (corresponding to a different
host interrupt).

How do that work ?

Cheers,
Ben.