implement evtchn support

xenevtchn/src/lib.rs

@@ -0,0 +1,103 @@
+pub mod sys;
+
+use crate::sys::{BindInterdomain, BindUnboundPort, BindVirq, Notify, UnbindPort};
+use nix::errno::Errno;
+use std::error::Error;
+use std::fmt::{Display, Formatter};
+use std::fs::{File, OpenOptions};
+use std::os::fd::AsRawFd;
+
+pub struct EventChannel {
+    pub handle: File,
+}
+
+#[derive(Debug)]
+pub struct EventChannelError {
+    message: String,
+}
+
+impl EventChannelError {
+    pub fn new(msg: &str) -> EventChannelError {
+        EventChannelError {
+            message: msg.to_string(),
+        }
+    }
+}
+
+impl Display for EventChannelError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl Error for EventChannelError {
+    fn description(&self) -> &str {
+        &self.message
+    }
+}
+
+impl From<std::io::Error> for EventChannelError {
+    fn from(value: std::io::Error) -> Self {
+        EventChannelError::new(value.to_string().as_str())
+    }
+}
+
+impl From<Errno> for EventChannelError {
+    fn from(value: Errno) -> Self {
+        EventChannelError::new(value.to_string().as_str())
+    }
+}
+
+impl EventChannel {
+    pub fn open() -> Result<EventChannel, EventChannelError> {
+        let file = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .open("/dev/xen/evtchn")?;
+        Ok(EventChannel { handle: file })
+    }
+
+    pub fn bind_virq(&mut self, virq: u32) -> Result<u32, EventChannelError> {
+        unsafe {
+            let mut request = BindVirq { virq };
+            Ok(sys::bind_virq(self.handle.as_raw_fd(), &mut request)? as u32)
+        }
+    }
+
+    pub fn bind_interdomain(&mut self, domid: u32, port: u32) -> Result<u32, EventChannelError> {
+        unsafe {
+            let mut request = BindInterdomain {
+                remote_domain: domid,
+                remote_port: port,
+            };
+            Ok(sys::bind_interdomain(self.handle.as_raw_fd(), &mut request)? as u32)
+        }
+    }
+
+    pub fn bind_unbound_port(&mut self, domid: u32) -> Result<u32, EventChannelError> {
+        unsafe {
+            let mut request = BindUnboundPort {
+                remote_domain: domid,
+            };
+            Ok(sys::bind_unbound_port(self.handle.as_raw_fd(), &mut request)? as u32)
+        }
+    }
+
+    pub fn unbind(&mut self, port: u32) -> Result<u32, EventChannelError> {
+        unsafe {
+            let mut request = UnbindPort { port };
+            Ok(sys::unbind(self.handle.as_raw_fd(), &mut request)? as u32)
+        }
+    }
+
+    pub fn notify(&mut self, port: u32) -> Result<u32, EventChannelError> {
+        unsafe {
+            let mut request = Notify { port };
+            Ok(sys::notify(self.handle.as_raw_fd(), &mut request)? as u32)
+        }
+    }
+
+    pub fn reset(&mut self) -> Result<u32, EventChannelError> {
+        unsafe { Ok(sys::reset(self.handle.as_raw_fd())? as u32) }
+    }
+}

xenevtchn/src/sys.rs

@@ -0,0 +1,43 @@
+use nix::{ioctl_none, ioctl_readwrite_bad, request_code_none};
+use std::ffi::c_uint;
+
+#[repr(C)]
+pub struct BindVirq {
+    pub virq: c_uint,
+}
+
+#[repr(C)]
+pub struct BindInterdomain {
+    pub remote_domain: c_uint,
+    pub remote_port: c_uint,
+}
+
+#[repr(C)]
+pub struct BindUnboundPort {
+    pub remote_domain: c_uint,
+}
+
+#[repr(C)]
+pub struct UnbindPort {
+    pub port: c_uint,
+}
+
+#[repr(C)]
+pub struct Notify {
+    pub port: c_uint,
+}
+
+ioctl_readwrite_bad!(bind_virq, request_code_none!(b'E', 0), BindVirq);
+ioctl_readwrite_bad!(
+    bind_interdomain,
+    request_code_none!(b'E', 1),
+    BindInterdomain
+);
+ioctl_readwrite_bad!(
+    bind_unbound_port,
+    request_code_none!(b'E', 2),
+    BindUnboundPort
+);
+ioctl_readwrite_bad!(unbind, request_code_none!(b'E', 3), UnbindPort);
+ioctl_readwrite_bad!(notify, request_code_none!(b'E', 4), Notify);
+ioctl_none!(reset, b'E', 5);