2 files changed, 71 insertions, 0 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index a1f2200e43d0..66b58e494935 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 000000000000..34a69834124a
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/README
@@ -0,0 +1 @@
+This directory contains specific device bindings for KVM_CAP_DEVICE_CTRL.