KVM: arm/arm64: vgic-new: Add MMIO handling framework

Add an MMIO handling framework to the VGIC emulation:
Each register is described by its offset, size (or number of bits per
IRQ, if applicable) and the read/write handler functions. We provide
initialization macros to describe each GIC register later easily.

Separate dispatch functions for read and write accesses are connected
to the kvm_io_bus framework and binary-search for the responsible
register handler based on the offset address within the region.
We convert the incoming data (referenced by a pointer) to the host's
endianess and use pass-by-value to hand the data over to the actual
handler functions.

The register handler prototype and the endianess conversion are
courtesy of Christoffer Dall.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
index f663288..ff3f9c2 100644
--- a/include/kvm/vgic/vgic.h
+++ b/include/kvm/vgic/vgic.h
@@ -106,6 +106,16 @@ struct vgic_irq {
 	enum vgic_irq_config config;	/* Level or edge */
 };
 
+struct vgic_register_region;
+
+struct vgic_io_device {
+	gpa_t base_addr;
+	struct kvm_vcpu *redist_vcpu;
+	const struct vgic_register_region *regions;
+	int nr_regions;
+	struct kvm_io_device dev;
+};
+
 struct vgic_dist {
 	bool			in_kernel;
 	bool			ready;
@@ -132,6 +142,9 @@ struct vgic_dist {
 	bool			enabled;
 
 	struct vgic_irq		*spis;
+
+	struct vgic_io_device	dist_iodev;
+	struct vgic_io_device	*redist_iodevs;
 };
 
 struct vgic_v2_cpu_if {