We want to be able to reuse the SerialBuffer from the virtio-devices
crate, particularly from the virtio-console implementation. That's why
we move the SerialBuffer definition to its own crate so that it can be
accessed from both vmm and virtio-devices crates, without creating any
cyclic dependency.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
If the epoll_wait() call returns EINTR, this only means a signal has
been delivered before any of the file descriptors registered triggered
an event or before the end of the timeout (if timeout isn't -1). For
that reason, we should simply try to listen on the epoll loop again.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The goal of this patch is to provide a reliable way to detect when the
other end of the PTY is connected, and therefore be able to identify
when we can write to the PTY device. This is needed because writing to
the PTY device when the other end isn't connected causes the loss of
the written bytes.
The way to detect the connection on the other end of the PTY is by
knowing the other end is disconnected at first with the presence of the
EPOLLHUP event. Later on, when the connection happens, EPOLLHUP is not
triggered anymore, and that's when we can assume it's okay to write to
the PTY main device.
It's important to note we had to ensure the file descriptor for the
other end was closed, otherwise we would have never seen the EPOLLHUP
event. And we did so by removing the "sub" field from the PtyPair
structure as it was keeping the associated File opened.
Fixes#3170
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
warning: you are deriving `PartialEq` and can implement `Eq`
--> vmm/src/serial_manager.rs:59:30
|
59 | #[derive(Debug, Clone, Copy, PartialEq)]
| ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Refactor the serial buffer handling in order to write the serial
buffer's output to a PTY connected after the serial device stops being
written to by the guest.
This change moves the serial buffer initialization inside the serial
manager. That is done to allow the serial buffer to be made aware of
the PTY and epoll fds needed in order to modify the
EpollDispatch::File trigger. These are then used by the serial buffer
to trigger an epoll event when the PTY fd is writable and the buffer
has content in it. They are also used to remove the trigger when the
buffer is emptied in order to avoid unnecessary wake-ups.
Signed-off-by: William Douglas <william.douglas@intel.com>
This change adds a SerialManager with its own epoll handling that
should be created and run by the DeviceManager when creating an
appropriately configured console (serial tty or pty).
Both stdin and pty input are handled by the SerialManager. The stdin
and pty specific methods used by the VMM should be removed in a future
commit.
Signed-off-by: William Douglas <william.douglas@intel.com>
