KVM: arm/arm64: add irqfd support
This patch enables irqfd on arm/arm64.
Both irqfd and resamplefd are supported. Injection is implemented
in vgic.c without routing.
This patch enables CONFIG_HAVE_KVM_EVENTFD and CONFIG_HAVE_KVM_IRQFD.
KVM_CAP_IRQFD is now advertised. KVM_CAP_IRQFD_RESAMPLE capability
automatically is advertised as soon as CONFIG_HAVE_KVM_IRQFD is set.
Irqfd injection is restricted to SPI. The rationale behind not
supporting PPI irqfd injection is that any device using a PPI would
be a private-to-the-CPU device (timer for instance), so its state
would have to be context-switched along with the VCPU and would
require in-kernel wiring anyhow. It is not a relevant use case for
irqfds.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index 83a448e..f1f79d1 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -28,6 +28,8 @@
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
select SRCU
select MMU_NOTIFIER
+ select HAVE_KVM_EVENTFD
+ select HAVE_KVM_IRQFD
depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
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