2 // SPDX-License-Identifier: Apache-2.0 or BSD-3-Clause
7 //! is a set of three different single-producer, single-consumer ring structures designed to store
8 //! generic scatter-gather I/O. The virtio specification 1.1 introduces an alternative compact
10 //! hardware implemented virtio devices. The packed virtqueue uses read-write memory, that means
25 //! Later Vhost-user protocol is introduced to complement the ioctl interface used to control the
35 #[cfg_attr(feature = "vhost-user", macro_use)]
37 #[cfg_attr(feature = "vhost-kern", macro_use)]
43 #[cfg(feature = "vhost-net")]
45 #[cfg(feature = "vhost-vdpa")]
47 #[cfg(feature = "vhost-kern")]
49 #[cfg(feature = "vhost-user")]
51 #[cfg(feature = "vhost-vsock")]
54 /// Error codes for vhost operations
56 pub enum Error {  enum
75     #[cfg(feature = "vhost-kern")]
76     /// Error opening the vhost backend driver.
77     VhostOpen(std::io::Error),
78     #[cfg(feature = "vhost-kern")]
79     /// Error while running ioctl.
80     IoctlError(std::io::Error),
81     /// Error from IO subsystem.
82     IOError(std::io::Error),
83     #[cfg(feature = "vhost-user")]
84     /// Error from the vhost-user subsystem.
85     VhostUserProtocol(vhost_user::Error),
88 impl std::fmt::Display for Error {  implementation
89     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {  in fmt()
91             Error::InvalidOperation => write!(f, "invalid vhost operations"),  in fmt()
92             Error::InvalidGuestMemory => write!(f, "invalid guest memory object"),  in fmt()
93             Error::InvalidGuestMemoryRegion => write!(f, "invalid guest memory region"),  in fmt()
94             Error::InvalidIotlbMsg => write!(f, "invalid IOTLB message"),  in fmt()
95             Error::InvalidQueue => write!(f, "invalid virtqueue"),  in fmt()
96             Error::DescriptorTableAddress => {  in fmt()
97                 write!(f, "invalid virtqueue descriptor table address")  in fmt()
99             Error::UsedAddress => write!(f, "invalid virtqueue used table address"),  in fmt()
100             Error::AvailAddress => write!(f, "invalid virtqueue available table address"),  in fmt()
101             Error::LogAddress => write!(f, "invalid virtqueue log address"),  in fmt()
102             Error::IOError(e) => write!(f, "IO error: {}", e),  in fmt()
103             #[cfg(feature = "vhost-kern")]  in fmt()
104             Error::VhostOpen(e) => write!(f, "failure in opening vhost file: {}", e),  in fmt()
105             #[cfg(feature = "vhost-kern")]  in fmt()
106             Error::IoctlError(e) => write!(f, "failure in vhost ioctl: {}", e),  in fmt()
107             #[cfg(feature = "vhost-user")]  in fmt()
108             Error::VhostUserProtocol(e) => write!(f, "vhost-user: {}", e),  in fmt()
113 impl std::error::Error for Error {}  implementation
115 #[cfg(feature = "vhost-user")]
116 impl std::convert::From<vhost_user::Error> for Error {  implementation
117     fn from(err: vhost_user::Error) -> Self {  in from()
118         Error::VhostUserProtocol(err)  in from()
123 pub type Result<T> = std::result::Result<T, Error>;
132             format!("{}", Error::AvailAddress),  in test_error()
136             format!("{}", Error::InvalidOperation),  in test_error()
140             format!("{}", Error::InvalidGuestMemory),  in test_error()
144             format!("{}", Error::InvalidGuestMemoryRegion),  in test_error()
148             format!("{}", Error::InvalidIotlbMsg),  in test_error()
151         assert_eq!(format!("{}", Error::InvalidQueue), "invalid virtqueue");  in test_error()
153             format!("{}", Error::DescriptorTableAddress),  in test_error()
157             format!("{}", Error::UsedAddress),  in test_error()
161             format!("{}", Error::LogAddress),  in test_error()
165         assert_eq!(format!("{:?}", Error::AvailAddress), "AvailAddress");  in test_error()
168     #[cfg(feature = "vhost-user")]
171         let e: Error = vhost_user::Error::OversizedMsg.into();  in test_convert_from_vhost_user_error()
173         assert_eq!(format!("{}", e), "vhost-user: oversized message");  in test_convert_from_vhost_user_error()