[RFC 6/6] KVM: arm: implement kvm_set_msi by gsi direct mapping

[Eric Auger <eric.auger@linaro.org>]

If the ITS modality is not available, let's simply support MSI
injection by transforming the MSI.data into an SPI ID.

This becomes possible to use KVM_SIGNAL_MSI ioctl for arm too.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 arch/arm/kvm/Kconfig | 1 +
 virt/kvm/arm/vgic.c  | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index 151e710..0f58baf 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -31,6 +31,7 @@ config KVM
 	select KVM_VFIO
 	select HAVE_KVM_EVENTFD
 	select HAVE_KVM_IRQFD
+	select HAVE_KVM_MSI
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_IRQ_ROUTING
 	depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 16d232f..40e96f9 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -2293,6 +2293,11 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 			return kvm->arch.vgic.vm_ops.inject_msi(kvm, &msi);
 		else
 			return -ENODEV;
+	case KVM_IRQ_ROUTING_MSI:
+		if (kvm->arch.vgic.vm_ops.inject_msi)
+			return -EINVAL;
+		else
+			return kvm_vgic_inject_irq(kvm, 0, e->msi.data, level);
 	default:
 		return -EINVAL;
 	}
-- 
1.9.1