[PATCH v4 03/12] KVM: arm64: Introduce new MMIO region for the ITS base address

[Chalamarla, Tirumalesh]

On 3/25/16, 7:14 PM, "kvmarm-bounces at lists.cs.columbia.edu on behalf of Andre Przywara" <kvmarm-bounces at lists.cs.columbia.edu on behalf of andre.przywara at arm.com> wrote:

>The ARM GICv3 ITS controller requires a separate register frame to
>cover ITS specific registers. Add a new VGIC address type and store
>the address in a field in the vgic_dist structure.
>Provide a function to check whether userland has provided the address,
>so ITS functionality can be guarded by that check.
>
>Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>---
> Documentation/virtual/kvm/devices/arm-vgic.txt |  9 +++++++++
> arch/arm64/include/uapi/asm/kvm.h              |  2 ++
> include/kvm/vgic/vgic.h                        |  5 +++++
> virt/kvm/arm/vgic/vgic.c                       | 10 ++++++++++
> virt/kvm/arm/vgic/vgic_init.c                  |  1 +
> virt/kvm/arm/vgic/vgic_kvm_device.c            |  7 +++++++
> 6 files changed, 34 insertions(+)
>
>diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
>index 59541d4..087e2d9 100644
>--- a/Documentation/virtual/kvm/devices/arm-vgic.txt
>+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
>@@ -39,6 +39,15 @@ Groups:
>       Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
>       This address needs to be 64K aligned.
> 
>+    KVM_VGIC_V3_ADDR_TYPE_ITS (rw, 64-bit)
>+      Base address in the guest physical address space of the GICv3 ITS
>+      control register frame. The ITS allows MSI(-X) interrupts to be
>+      injected into guests. This extension is optional, if the kernel
>+      does not support the ITS, the call returns -ENODEV.
>+      This memory is solely for the guest to access the ITS control
>+      registers and does not cover the ITS translation register.
>+      Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
>+      This address needs to be 64K aligned and the region covers 64 KByte.
> 
>   KVM_DEV_ARM_VGIC_GRP_DIST_REGS
>   Attributes:
>diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
>index f209ea1..c2b257d 100644
>--- a/arch/arm64/include/uapi/asm/kvm.h
>+++ b/arch/arm64/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_V3_ADDR_TYPE_ITS	4
> 
> #define KVM_VGIC_V3_DIST_SIZE		SZ_64K
> #define KVM_VGIC_V3_REDIST_SIZE		(2 * SZ_64K)
>+#define KVM_VGIC_V3_ITS_SIZE		SZ_64K
> 
> #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
> #define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */
>diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
>index 7c1d145..11344e6 100644
>--- a/include/kvm/vgic/vgic.h
>+++ b/include/kvm/vgic/vgic.h
>@@ -135,6 +135,9 @@ struct vgic_dist {
> 		gpa_t			vgic_redist_base;
> 	};
> 
>+	/* The base address of the ITS control register frame */
>+	gpa_t			vgic_its_base;
>+
> 	/* distributor enabled */
> 	u32			enabled;
> 
>@@ -253,4 +256,6 @@ static inline int kvm_vgic_get_max_vcpus(void)
> 	return kvm_vgic_global_state.max_gic_vcpus;
> }
> 
>+bool vgic_has_its(struct kvm *kvm);
>+
> #endif /* __ASM_ARM_KVM_VGIC_VGIC_H */
>diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
>index 65395af..1de2478 100644
>--- a/virt/kvm/arm/vgic/vgic.c
>+++ b/virt/kvm/arm/vgic/vgic.c
>@@ -612,3 +612,13 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, u32 intid)
> 
> 	return map_is_active;
> }
>+
>+bool vgic_has_its(struct kvm *kvm)
>+{
>+	struct vgic_dist *dist = &kvm->arch.vgic;
>+
>+	if (dist->vgic_model != KVM_DEV_TYPE_ARM_VGIC_V3)
>+		return false;
>+
>+	return !IS_VGIC_ADDR_UNDEF(dist->vgic_its_base);
>+}
>diff --git a/virt/kvm/arm/vgic/vgic_init.c b/virt/kvm/arm/vgic/vgic_init.c
>index ac655b5..2301e03 100644
>--- a/virt/kvm/arm/vgic/vgic_init.c
>+++ b/virt/kvm/arm/vgic/vgic_init.c
>@@ -132,6 +132,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
> 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
> 	kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
> 	kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
>+	kvm->arch.vgic.vgic_its_base = VGIC_ADDR_UNDEF;
> 
> out_unlock:
> 	for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
>diff --git a/virt/kvm/arm/vgic/vgic_kvm_device.c b/virt/kvm/arm/vgic/vgic_kvm_device.c
>index 7f78a16..3ec2ac3 100644
>--- a/virt/kvm/arm/vgic/vgic_kvm_device.c
>+++ b/virt/kvm/arm/vgic/vgic_kvm_device.c
>@@ -109,6 +109,12 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> 		block_size = KVM_VGIC_V3_REDIST_SIZE;
> 		alignment = SZ_64K;
> 		break;
>+	case KVM_VGIC_V3_ADDR_TYPE_ITS:
>+		type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
>+		addr_ptr = &vgic->vgic_its_base;
>+		block_size = KVM_VGIC_V3_ITS_SIZE;
>+		alignment = SZ_64K;
>+		break;

Should there be a check based on number of vcpus? 
> #endif
> 	default:
> 		r = -ENODEV;
>@@ -495,6 +501,7 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
> 		switch (attr->attr) {
> 		case KVM_VGIC_V3_ADDR_TYPE_DIST:
> 		case KVM_VGIC_V3_ADDR_TYPE_REDIST:
>+		case KVM_VGIC_V3_ADDR_TYPE_ITS:
> 			return 0;
> 		}
> 		break;
>-- 
>2.7.3
>
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