[PATCH 3/8] KVM: arm-vgic: Set base addr through device API

Christoffer Dall christoffer.dall at linaro.org
Fri Aug 23 15:20:01 EDT 2013


Support setting the distributor and cpu interface base addresses in the
VM physical address space through the KVM_{SET,GET}_DEVICE_ATTR API
in addition to the ARM specific API.

This has the added benefit of being able to share more code in user
space and do things in a uniform maner.

Also deprecate the older API at the same time, but backwards
compatibility will be maintained.

Reviewed-by: Alexander Graf <agraf at suse.de>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
 Documentation/virtual/kvm/api.txt              |    6 +-
 Documentation/virtual/kvm/devices/arm-vgic.txt |   11 +++
 arch/arm/include/uapi/asm/kvm.h                |    9 +++
 arch/arm/kvm/arm.c                             |    2 +-
 include/kvm/arm_vgic.h                         |    2 +-
 virt/kvm/arm/vgic.c                            |   90 ++++++++++++++++++++----
 6 files changed, 105 insertions(+), 15 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index ef925ea..594a3be 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2324,7 +2324,7 @@ This ioctl returns the guest registers that are supported for the
 KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
 
 
-4.84 KVM_ARM_SET_DEVICE_ADDR
+4.84 KVM_ARM_SET_DEVICE_ADDR (deprecated)
 
 Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
 Architectures: arm, arm64
@@ -2362,6 +2362,10 @@ must be called after calling KVM_CREATE_IRQCHIP, but before calling
 KVM_RUN on any of the VCPUs.  Calling this ioctl twice for any of the
 base addresses will return -EEXIST.
 
+Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API
+should be used instead.
+
+
 4.85 KVM_PPC_RTAS_DEFINE_TOKEN
 
 Capability: KVM_CAP_PPC_RTAS
diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
index 38f27f7..c9febb2 100644
--- a/Documentation/virtual/kvm/devices/arm-vgic.txt
+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
@@ -8,3 +8,14 @@ Only one VGIC instance may be instantiated through either this API or the
 legacy KVM_CREATE_IRQCHIP api.  The created VGIC will act as the VM interrupt
 controller, requiring emulated user-space devices to inject interrupts to the
 VGIC instead of directly to CPUs.
+
+Groups:
+  KVM_DEV_ARM_VGIC_GRP_ADDR
+  Attributes:
+    KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
+      Base address in the guest physical address space of the GIC distributor
+      register mappings.
+
+    KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
+      Base address in the guest physical address space of the GIC virtual cpu
+      interface register mappings.
diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index 1c85102..587f1ae 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -142,6 +142,15 @@ struct kvm_arch_memory_slot {
 #define KVM_REG_ARM_VFP_FPINST		0x1009
 #define KVM_REG_ARM_VFP_FPINST2		0x100A
 
+/* Device Control API: ARM VGIC */
+#define KVM_DEV_ARM_VGIC_GRP_ADDR	0
+#define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1
+#define KVM_DEV_ARM_VGIC_GRP_CPU_REGS	2
+#define   KVM_DEV_ARM_VGIC_CPUID_SHIFT	32
+#define   KVM_DEV_ARM_VGIC_CPUID_MASK	(0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT)
+#define   KVM_DEV_ARM_VGIC_OFFSET_SHIFT	0
+#define   KVM_DEV_ARM_VGIC_OFFSET_MASK	(0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT)
+
 /* KVM_IRQ_LINE irq field index values */
 #define KVM_ARM_IRQ_TYPE_SHIFT		24
 #define KVM_ARM_IRQ_TYPE_MASK		0xff
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index c7b7474..0208ed1 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -769,7 +769,7 @@ static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
 	case KVM_ARM_DEVICE_VGIC_V2:
 		if (!vgic_present)
 			return -ENXIO;
-		return kvm_vgic_set_addr(kvm, type, dev_addr->addr);
+		return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
 	default:
 		return -ENODEV;
 	}
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 7e2d158..be85127 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -144,7 +144,7 @@ struct kvm_run;
 struct kvm_exit_mmio;
 
 #ifdef CONFIG_KVM_ARM_VGIC
-int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr);
+int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
 int kvm_vgic_hyp_init(void);
 int kvm_vgic_init(struct kvm *kvm);
 int kvm_vgic_create(struct kvm *kvm);
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 140608a..a51efb8 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1481,6 +1481,12 @@ static int vgic_ioaddr_assign(struct kvm *kvm, phys_addr_t *ioaddr,
 {
 	int ret;
 
+	if (addr & ~KVM_PHYS_MASK)
+		return -E2BIG;
+
+	if (addr & (SZ_4K - 1))
+		return -EINVAL;
+
 	if (!IS_VGIC_ADDR_UNDEF(*ioaddr))
 		return -EEXIST;
 	if (addr + size < addr)
@@ -1493,26 +1499,41 @@ static int vgic_ioaddr_assign(struct kvm *kvm, phys_addr_t *ioaddr,
 	return ret;
 }
 
-int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
+/**
+ * kvm_vgic_addr - set or get vgic VM base addresses
+ * @kvm:   pointer to the vm struct
+ * @type:  the VGIC addr type, one of KVM_VGIC_V2_ADDR_TYPE_XXX
+ * @addr:  pointer to address value
+ * @write: if true set the address in the VM address space, if false read the
+ *          address
+ *
+ * Set or get the vgic base addresses for the distributor and the virtual CPU
+ * interface in the VM physical address space.  These addresses are properties
+ * of the emulated core/SoC and therefore user space initially knows this
+ * information.
+ */
+int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
 {
 	int r = 0;
 	struct vgic_dist *vgic = &kvm->arch.vgic;
 
-	if (addr & ~KVM_PHYS_MASK)
-		return -E2BIG;
-
-	if (addr & (SZ_4K - 1))
-		return -EINVAL;
-
 	mutex_lock(&kvm->lock);
 	switch (type) {
 	case KVM_VGIC_V2_ADDR_TYPE_DIST:
-		r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base,
-				       addr, KVM_VGIC_V2_DIST_SIZE);
+		if (write) {
+			r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base,
+					       *addr, KVM_VGIC_V2_DIST_SIZE);
+		} else {
+			*addr = vgic->vgic_dist_base;
+		}
 		break;
 	case KVM_VGIC_V2_ADDR_TYPE_CPU:
-		r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base,
-				       addr, KVM_VGIC_V2_CPU_SIZE);
+		if (write) {
+			r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base,
+					       *addr, KVM_VGIC_V2_CPU_SIZE);
+		} else {
+			*addr = vgic->vgic_cpu_base;
+		}
 		break;
 	default:
 		r = -ENODEV;
@@ -1524,16 +1545,61 @@ int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
 
 static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
+	int r;
+
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
+		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+		u64 addr;
+		unsigned long type = (unsigned long)attr->attr;
+
+		if (copy_from_user(&addr, uaddr, sizeof(addr)))
+			return -EFAULT;
+
+		r = kvm_vgic_addr(dev->kvm, type, &addr, true);
+		return (r == -ENODEV) ? -ENXIO : r;
+	}
+	}
+
 	return -ENXIO;
 }
 
 static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
-	return -ENXIO;
+	int r = ENXIO;
+
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
+		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+		u64 addr;
+		unsigned long type = (unsigned long)attr->attr;
+
+		r = kvm_vgic_addr(dev->kvm, type, &addr, false);
+		if (r)
+			return (r == -ENODEV) ? -ENXIO : r;
+
+		r = 0;
+		if (copy_to_user(uaddr, &addr, sizeof(addr)))
+			return -EFAULT;
+	}
+	}
+
+	return r;
 }
 
 static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
+	phys_addr_t offset;
+
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_ADDR:
+		switch (attr->attr) {
+		case KVM_VGIC_V2_ADDR_TYPE_DIST:
+		case KVM_VGIC_V2_ADDR_TYPE_CPU:
+			return 0;
+		}
+		break;
+	}
 	return -ENXIO;
 }
 
-- 
1.7.10.4




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