From mboxrd@z Thu Jan  1 00:00:00 1970
From: p.fedin@samsung.com (Pavel Fedin)
Date: Tue, 07 Jul 2015 13:57:51 +0300
Subject: [PATCH 1/7] KVM: api: add kvm_irq_routing_extended_msi
In-Reply-To: <559BA3BD.60404@arm.com>
References: <1435592237-17924-1-git-send-email-eric.auger@linaro.org>
 <1435592237-17924-2-git-send-email-eric.auger@linaro.org>
 <011f01d0b498$6a17aeb0$3e470c10$@samsung.com> <5596503E.6040902@arm.com>
 <00fd01d0b7b6$f6cf3550$e46d9ff0$@samsung.com> <559A3C9C.6050302@arm.com>
 <20150706093026.GA11590@cbox> <559A52E6.5050402@arm.com>
 <20150706103755.GC11590@cbox> <559A6164.1000401@redhat.com>
 <559A6527.1040107@arm.com> <559A6BBC.2040901@redhat.com>
 <024301d0b7f0$2b13b410$813b1c30$@samsung.com> <559AA0D6.7070703@arm.com>
 <014c01d0b884$deff46d0$9cfdd470$@samsung.com> <559BA3BD.60404@arm.com>
Message-ID: <023301d0b8a3$c5a30680$50e91380$@samsung.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

> I just don't want to end up with something like:
> (GICV3 && ARM64) || (GICV3 && ARM && KERNEL>4.4) || (SuperIRQC && i986)
> or
> (ARM || ARM64) && HAS_IRQ_ROUTING
> 
> Instead: If the kernel needs it, it tells you. Full stop.

 Agree.

> To be honest it's me to blame here to not having introduced the
> capability earlier. At the moment ARM has a different code path for
> KVM_SIGNAL_MSI, which does not bail out if the flag field is set. With
> Eric's patches this changes and we use the irqchip.c generic code, which
> returns -EINVAL atm. So I plan to introduce this capability already with
> the ITS emulation series, so we can just pick it up in the IRQ routing
> series.

 Then may be you follow https://lkml.org/lkml/2015/7/7/115 and replace flag with something like
KVM_SIGNAL_EXT_MSI ioctl ? After all you were one of people who voted against using flags.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia