KVM: arm-vgic: Set base addr through device API

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 manner.

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

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index a30035d..867112f 100644 (file)
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2391,7 +2391,8 @@ struct kvm_reg_list {
 This ioctl returns the guest registers that are supported for the
 KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
 
-4.85 KVM_ARM_SET_DEVICE_ADDR
+
+4.85 KVM_ARM_SET_DEVICE_ADDR (deprecated)
 
 Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
 Architectures: arm, arm64
@@ -2429,6 +2430,10 @@ 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.
+
+
 4.86 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 (file)
--- 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 835b867..76a7427 100644 (file)
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -163,6 +163,8 @@ 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
 
 /* KVM_IRQ_LINE irq field index values */
 #define KVM_ARM_IRQ_TYPE_SHIFT         24

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index cc7c41a..f290b22 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -776,7 +776,7 @@ 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 (file)
--- 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 b15d6c1..45db48d 100644 (file)
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1495,6 +1495,12 @@ 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)
@@ -1507,26 +1513,41 @@ 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;
@@ -1538,16 +1559,58 @@ 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;
+
+               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)
 {
+       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;
 }