ARM: KVM: Support vGICv3 ITS

This patch allows to build and use vGICv3 ITS in 32-bit mode.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Documentation/virtual/kvm/api.txt

@@ -2198,7 +2198,7 @@ after pausing the vcpu, but before it is resumed.
 4.71 KVM_SIGNAL_MSI
 
 Capability: KVM_CAP_SIGNAL_MSI
-Architectures: x86 arm64
+Architectures: x86 arm arm64
 Type: vm ioctl
 Parameters: struct kvm_msi (in)
 Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error

arch/arm/include/uapi/asm/kvm.h

@@ -87,9 +87,11 @@ struct kvm_regs {
 /* Supported VGICv3 address types  */
 #define KVM_VGIC_V3_ADDR_TYPE_DIST	2
 #define KVM_VGIC_V3_ADDR_TYPE_REDIST	3
+#define KVM_VGIC_ITS_ADDR_TYPE		4
 
 #define KVM_VGIC_V3_DIST_SIZE		SZ_64K
 #define KVM_VGIC_V3_REDIST_SIZE		(2 * SZ_64K)
+#define KVM_VGIC_V3_ITS_SIZE		(2 * SZ_64K)
 
 #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
 #define KVM_ARM_VCPU_PSCI_0_2		1 /* CPU uses PSCI v0.2 */

arch/arm/kvm/Kconfig

@@ -34,6 +34,7 @@ config KVM
 	select HAVE_KVM_IRQFD
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_IRQ_ROUTING
+	select HAVE_KVM_MSI
 	depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
 	---help---
 	  Support hosting virtualized guest machines.

arch/arm/kvm/Makefile

@@ -32,5 +32,6 @@ obj-y += $(KVM)/arm/vgic/vgic-mmio.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio-v2.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio-v3.o
 obj-y += $(KVM)/arm/vgic/vgic-kvm-device.o
+obj-y += $(KVM)/arm/vgic/vgic-its.o
 obj-y += $(KVM)/irqchip.o
 obj-y += $(KVM)/arm/arch_timer.o

arch/arm/kvm/arm.c

@@ -221,6 +221,12 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_MSI_DEVID:
+		if (!kvm)
+			r = -EINVAL;
+		else
+			r = kvm->arch.vgic.msis_require_devid;
+		break;
 	default:
 		r = kvm_arch_dev_ioctl_check_extension(kvm, ext);
 		break;

arch/arm64/kvm/Kconfig

@@ -16,9 +16,6 @@ menuconfig VIRTUALIZATION
 
 if VIRTUALIZATION
 
-config KVM_ARM_VGIC_V3_ITS
-	bool
-
 config KVM
 	bool "Kernel-based Virtual Machine (KVM) support"
 	depends on OF
@@ -34,7 +31,6 @@ config KVM
 	select KVM_VFIO
 	select HAVE_KVM_EVENTFD
 	select HAVE_KVM_IRQFD
-	select KVM_ARM_VGIC_V3_ITS
 	select KVM_ARM_PMU if HW_PERF_EVENTS
 	select HAVE_KVM_MSI
 	select HAVE_KVM_IRQCHIP

arch/arm64/kvm/reset.c

@@ -86,12 +86,6 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_VCPU_ATTRIBUTES:
 		r = 1;
 		break;
-	case KVM_CAP_MSI_DEVID:
-		if (!kvm)
-			r = -EINVAL;
-		else
-			r = kvm->arch.vgic.msis_require_devid;
-		break;
 	default:
 		r = 0;
 	}

virt/kvm/arm/vgic/vgic-kvm-device.c

@@ -221,11 +221,9 @@ int kvm_register_vgic_device(unsigned long type)
 		ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
 					      KVM_DEV_TYPE_ARM_VGIC_V3);
 
-#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 		if (ret)
 			break;
 		ret = kvm_vgic_register_its_device();
-#endif
 		break;
 	}
 

virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -42,7 +42,6 @@ u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len,
 	return reg | ((u64)val << lower);
 }
 
-#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 bool vgic_has_its(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
@@ -52,7 +51,6 @@ bool vgic_has_its(struct kvm *kvm)
 
 	return dist->has_its;
 }
-#endif
 
 static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len)

virt/kvm/arm/vgic/vgic.h

@@ -84,37 +84,11 @@ int vgic_v3_probe(const struct gic_kvm_info *info);
 int vgic_v3_map_resources(struct kvm *kvm);
 int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
 
-#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 int vgic_register_its_iodevs(struct kvm *kvm);
 bool vgic_has_its(struct kvm *kvm);
 int kvm_vgic_register_its_device(void);
 void vgic_enable_lpis(struct kvm_vcpu *vcpu);
 int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi);
-#else
-static inline int vgic_register_its_iodevs(struct kvm *kvm)
-{
-	return -ENODEV;
-}
-
-static inline bool vgic_has_its(struct kvm *kvm)
-{
-	return false;
-}
-
-static inline int kvm_vgic_register_its_device(void)
-{
-	return -ENODEV;
-}
-
-static inline void vgic_enable_lpis(struct kvm_vcpu *vcpu)
-{
-}
-
-static inline int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
-{
-	return -ENODEV;
-}
-#endif
 
 int kvm_register_vgic_device(unsigned long type);
 int vgic_lazy_init(struct kvm *kvm);