diff options
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 70 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/README | 1 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 35 | ||||
| -rw-r--r-- | include/uapi/linux/kvm.h | 27 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 129 |
5 files changed, 262 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index a1f2200..66b58e4 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2189,6 +2189,76 @@ header; first `n_valid' valid entries with contents from the data written, then `n_invalid' invalid entries, invalidating any previously valid entries found. +4.79 KVM_CREATE_DEVICE + +Capability: KVM_CAP_DEVICE_CTRL +Type: vm ioctl +Parameters: struct kvm_create_device (in/out) +Returns: 0 on success, -1 on error +Errors: + ENODEV: The device type is unknown or unsupported + EEXIST: Device already created, and this type of device may not + be instantiated multiple times + + Other error conditions may be defined by individual device types or + have their standard meanings. + +Creates an emulated device in the kernel. The file descriptor returned +in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. + +If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the +device type is supported (not necessarily whether it can be created +in the current vm). + +Individual devices should not define flags. Attributes should be used +for specifying any behavior that is not implied by the device type +number. + +struct kvm_create_device { + __u32 type; /* in: KVM_DEV_TYPE_xxx */ + __u32 fd; /* out: device handle */ + __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ +}; + +4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR + +Capability: KVM_CAP_DEVICE_CTRL +Type: device ioctl +Parameters: struct kvm_device_attr +Returns: 0 on success, -1 on error +Errors: + ENXIO: The group or attribute is unknown/unsupported for this device + EPERM: The attribute cannot (currently) be accessed this way + (e.g. read-only attribute, or attribute that only makes + sense when the device is in a different state) + + Other error conditions may be defined by individual device types. + +Gets/sets a specified piece of device configuration and/or state. The +semantics are device-specific. See individual device documentation in +the "devices" directory. As with ONE_REG, the size of the data +transferred is defined by the particular attribute. + +struct kvm_device_attr { + __u32 flags; /* no flags currently defined */ + __u32 group; /* device-defined */ + __u64 attr; /* group-defined */ + __u64 addr; /* userspace address of attr data */ +}; + +4.81 KVM_HAS_DEVICE_ATTR + +Capability: KVM_CAP_DEVICE_CTRL +Type: device ioctl +Parameters: struct kvm_device_attr +Returns: 0 on success, -1 on error +Errors: + ENXIO: The group or attribute is unknown/unsupported for this device + +Tests whether a device supports a particular attribute. A successful +return indicates the attribute is implemented. It does not necessarily +indicate that the attribute can be read or written in the device's +current state. "addr" is ignored. 4.77 KVM_ARM_VCPU_INIT diff --git a/Documentation/virtual/kvm/devices/README b/Documentation/virtual/kvm/devices/README new file mode 100644 index 0000000..34a6983 --- /dev/null +++ b/Documentation/virtual/kvm/devices/README @@ -0,0 +1 @@ +This directory contains specific device bindings for KVM_CAP_DEVICE_CTRL. diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index dcef724..6dab6b5 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1064,6 +1064,41 @@ static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu) extern bool kvm_rebooting; +struct kvm_device_ops; + +struct kvm_device { + struct kvm_device_ops *ops; + struct kvm *kvm; + atomic_t users; + void *private; +}; + +/* create, destroy, and name are mandatory */ +struct kvm_device_ops { + const char *name; + int (*create)(struct kvm_device *dev, u32 type); + + /* + * Destroy is responsible for freeing dev. + * + * Destroy may be called before or after destructors are called + * on emulated I/O regions, depending on whether a reference is + * held by a vcpu or other kvm component that gets destroyed + * after the emulated I/O. + */ + void (*destroy)(struct kvm_device *dev); + + int (*set_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); + int (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); + int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); + long (*ioctl)(struct kvm_device *dev, unsigned int ioctl, + unsigned long arg); +}; + +void kvm_device_get(struct kvm_device *dev); +void kvm_device_put(struct kvm_device *dev); +struct kvm_device *kvm_device_from_filp(struct file *filp); + #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index c741902..38a0be0 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -666,6 +666,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_PPC_EPR 86 #define KVM_CAP_ARM_PSCI 87 #define KVM_CAP_ARM_SET_DEVICE_ADDR 88 +#define KVM_CAP_DEVICE_CTRL 89 #ifdef KVM_CAP_IRQ_ROUTING @@ -819,6 +820,24 @@ struct kvm_arm_device_addr { }; /* + * Device control API, available with KVM_CAP_DEVICE_CTRL + */ +#define KVM_CREATE_DEVICE_TEST 1 + +struct kvm_create_device { + __u32 type; /* in: KVM_DEV_TYPE_xxx */ + __u32 fd; /* out: device handle */ + __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ +}; + +struct kvm_device_attr { + __u32 flags; /* no flags currently defined */ + __u32 group; /* device-defined */ + __u64 attr; /* group-defined */ + __u64 addr; /* userspace address of attr data */ +}; + +/* * ioctls for VM fds */ #define KVM_SET_MEMORY_REGION _IOW(KVMIO, 0x40, struct kvm_memory_region) @@ -906,6 +925,14 @@ struct kvm_s390_ucas_mapping { /* Available with KVM_CAP_ARM_SET_DEVICE_ADDR */ #define KVM_ARM_SET_DEVICE_ADDR _IOW(KVMIO, 0xab, struct kvm_arm_device_addr) +/* ioctl for vm fd */ +#define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device) + +/* ioctls for fds returned by KVM_CREATE_DEVICE */ +#define KVM_SET_DEVICE_ATTR _IOW(KVMIO, 0xe1, struct kvm_device_attr) +#define KVM_GET_DEVICE_ATTR _IOW(KVMIO, 0xe2, struct kvm_device_attr) +#define KVM_HAS_DEVICE_ATTR _IOW(KVMIO, 0xe3, struct kvm_device_attr) + /* * ioctls for vcpu fds */ diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f9492f3..5f0d78c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2159,6 +2159,117 @@ out: } #endif +static int kvm_device_ioctl_attr(struct kvm_device *dev, + int (*accessor)(struct kvm_device *dev, + struct kvm_device_attr *attr), + unsigned long arg) +{ + struct kvm_device_attr attr; + + if (!accessor) + return -EPERM; + + if (copy_from_user(&attr, (void __user *)arg, sizeof(attr))) + return -EFAULT; + + return accessor(dev, &attr); +} + +static long kvm_device_ioctl(struct file *filp, unsigned int ioctl, + unsigned long arg) +{ + struct kvm_device *dev = filp->private_data; + + switch (ioctl) { + case KVM_SET_DEVICE_ATTR: + return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg); + case KVM_GET_DEVICE_ATTR: + return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg); + case KVM_HAS_DEVICE_ATTR: + return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg); + default: + if (dev->ops->ioctl) + return dev->ops->ioctl(dev, ioctl, arg); + + return -ENOTTY; + } +} + +void kvm_device_get(struct kvm_device *dev) +{ + atomic_inc(&dev->users); +} + +void kvm_device_put(struct kvm_device *dev) +{ + if (atomic_dec_and_test(&dev->users)) + dev->ops->destroy(dev); +} + +static int kvm_device_release(struct inode *inode, struct file *filp) +{ + struct kvm_device *dev = filp->private_data; + struct kvm *kvm = dev->kvm; + + kvm_device_put(dev); + kvm_put_kvm(kvm); + return 0; +} + +static const struct file_operations kvm_device_fops = { + .unlocked_ioctl = kvm_device_ioctl, + .release = kvm_device_release, +}; + +struct kvm_device *kvm_device_from_filp(struct file *filp) +{ + if (filp->f_op != &kvm_device_fops) + return NULL; + + return filp->private_data; +} + +static int kvm_ioctl_create_device(struct kvm *kvm, + struct kvm_create_device *cd) +{ + struct kvm_device_ops *ops = NULL; + struct kvm_device *dev; + bool test = cd->flags & KVM_CREATE_DEVICE_TEST; + int ret; + + switch (cd->type) { + default: + return -ENODEV; + } + + if (test) + return 0; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + dev->ops = ops; + dev->kvm = kvm; + atomic_set(&dev->users, 1); + + ret = ops->create(dev, cd->type); + if (ret < 0) { + kfree(dev); + return ret; + } + + ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR); + if (ret < 0) { + ops->destroy(dev); + return ret; + } + + kvm_get_kvm(kvm); + cd->fd = ret; + return 0; +} + static long kvm_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -2304,6 +2415,24 @@ static long kvm_vm_ioctl(struct file *filp, break; } #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */ + case KVM_CREATE_DEVICE: { + struct kvm_create_device cd; + + r = -EFAULT; + if (copy_from_user(&cd, argp, sizeof(cd))) + goto out; + + r = kvm_ioctl_create_device(kvm, &cd); + if (r) + goto out; + + r = -EFAULT; + if (copy_to_user(argp, &cd, sizeof(cd))) + goto out; + + r = 0; + break; + } default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); if (r == -ENOTTY) |
