[PATCH v4 09/10] arm: add support for supplying GICv3 redistributor addresses

[Andre Przywara]

Instead of the GIC virtual CPU interface an emulated GICv3 needs to
have accesses to its emulated redistributors trapped in the guest.
Add code to tell the kernel about the mapping if a GICv3 emulation was
requested by the user.

This contains some defines which are not (yet) in the (32 bit) header
files to allow compilation for ARM.

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
---
 arm/gic.c                         | 36 +++++++++++++++++++++++++++++++++++-
 arm/include/arm-common/gic.h      |  1 +
 arm/include/arm-common/kvm-arch.h |  7 +++++++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/arm/gic.c b/arm/gic.c
index b6c5868..efe4b42 100644
--- a/arm/gic.c
+++ b/arm/gic.c
@@ -9,7 +9,18 @@
 #include <linux/kernel.h>
 #include <linux/kvm.h>
 
+/* Those names are not defined for ARM (yet) */
+#ifndef KVM_VGIC_V3_ADDR_TYPE_DIST
+#define KVM_VGIC_V3_ADDR_TYPE_DIST 2
+#endif
+
+#ifndef KVM_VGIC_V3_ADDR_TYPE_REDIST
+#define KVM_VGIC_V3_ADDR_TYPE_REDIST 3
+#endif
+
 static int gic_fd = -1;
+static u64 gic_redists_base;
+static u64 gic_redists_size;
 
 static int gic__create_device(struct kvm *kvm, enum irqchip_type type)
 {
@@ -28,12 +39,21 @@ static int gic__create_device(struct kvm *kvm, enum irqchip_type type)
 		.group	= KVM_DEV_ARM_VGIC_GRP_ADDR,
 		.addr	= (u64)(unsigned long)&dist_addr,
 	};
+	struct kvm_device_attr redist_attr = {
+		.group	= KVM_DEV_ARM_VGIC_GRP_ADDR,
+		.attr	= KVM_VGIC_V3_ADDR_TYPE_REDIST,
+		.addr	= (u64)(unsigned long)&gic_redists_base,
+	};
 
 	switch (type) {
 	case IRQCHIP_GICV2:
 		gic_device.type = KVM_DEV_TYPE_ARM_VGIC_V2;
 		dist_attr.attr  = KVM_VGIC_V2_ADDR_TYPE_DIST;
 		break;
+	case IRQCHIP_GICV3:
+		gic_device.type = KVM_DEV_TYPE_ARM_VGIC_V3;
+		dist_attr.attr  = KVM_VGIC_V3_ADDR_TYPE_DIST;
+		break;
 	}
 
 	err = ioctl(kvm->vm_fd, KVM_CREATE_DEVICE, &gic_device);
@@ -46,6 +66,9 @@ static int gic__create_device(struct kvm *kvm, enum irqchip_type type)
 	case IRQCHIP_GICV2:
 		err = ioctl(gic_fd, KVM_SET_DEVICE_ATTR, &cpu_if_attr);
 		break;
+	case IRQCHIP_GICV3:
+		err = ioctl(gic_fd, KVM_SET_DEVICE_ATTR, &redist_attr);
+		break;
 	}
 	if (err)
 		goto out_err;
@@ -97,6 +120,10 @@ int gic__create(struct kvm *kvm, enum irqchip_type type)
 	switch (type) {
 	case IRQCHIP_GICV2:
 		break;
+	case IRQCHIP_GICV3:
+		gic_redists_size = kvm->cfg.nrcpus * ARM_GIC_REDIST_SIZE;
+		gic_redists_base = ARM_GIC_DIST_BASE - gic_redists_size;
+		break;
 	default:
 		return -ENODEV;
 	}
@@ -156,12 +183,19 @@ void gic__generate_fdt_nodes(void *fdt, u32 phandle, enum irqchip_type type)
 	const char *compatible;
 	u64 reg_prop[] = {
 		cpu_to_fdt64(ARM_GIC_DIST_BASE), cpu_to_fdt64(ARM_GIC_DIST_SIZE),
-		cpu_to_fdt64(ARM_GIC_CPUI_BASE), cpu_to_fdt64(ARM_GIC_CPUI_SIZE),
+		0, 0,				/* to be filled */
 	};
 
 	switch (type) {
 	case IRQCHIP_GICV2:
 		compatible = "arm,cortex-a15-gic";
+		reg_prop[2] = cpu_to_fdt64(ARM_GIC_CPUI_BASE);
+		reg_prop[3] = cpu_to_fdt64(ARM_GIC_CPUI_SIZE);
+		break;
+	case IRQCHIP_GICV3:
+		compatible = "arm,gic-v3";
+		reg_prop[2] = cpu_to_fdt64(gic_redists_base);
+		reg_prop[3] = cpu_to_fdt64(gic_redists_size);
 		break;
 	default:
 		return;
diff --git a/arm/include/arm-common/gic.h b/arm/include/arm-common/gic.h
index d524f55..4fde5ac 100644
--- a/arm/include/arm-common/gic.h
+++ b/arm/include/arm-common/gic.h
@@ -23,6 +23,7 @@
 
 enum irqchip_type {
 	IRQCHIP_GICV2,
+	IRQCHIP_GICV3,
 };
 
 struct kvm;
diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h
index 90d6733..0f5fb7f 100644
--- a/arm/include/arm-common/kvm-arch.h
+++ b/arm/include/arm-common/kvm-arch.h
@@ -30,6 +30,13 @@
 #define KVM_PCI_MMIO_AREA	(KVM_PCI_CFG_AREA + ARM_PCI_CFG_SIZE)
 #define KVM_VIRTIO_MMIO_AREA	ARM_MMIO_AREA
 
+/*
+ * On a GICv3 there must be one redistributor per vCPU.
+ * The value here is the size for one, we multiply this at runtime with
+ * the number of requested vCPUs to get the actual size.
+ */
+#define ARM_GIC_REDIST_SIZE	0x20000
+
 #define KVM_IRQ_OFFSET		GIC_SPI_IRQ_BASE
 
 #define KVM_VM_TYPE		0
-- 
2.3.5