This patch enables the vhost-user protocol features to let the slave
initiates some request towards the master (VMM). It also takes care of
receiving the requests from the slave and take appropriate actions based
on the request type.
The way the flow works now are as follow:
- The VMM creates a region of memory that is made available to the
guest by exposing it through the virtio-fs PCI BAR 2.
- The virtio-fs device is created by the VMM, exposing some protocol
features bits to virtiofsd, letting it know that it can send some
request to the VMM through a dedicated socket.
- On behalf of the guest driver asking for reading or writing a file,
virtiofsd sends a request to the VMM, asking for a file descriptor to
be mapped into the shared memory region at a specific offset.
- The guest can directly read/write the file at the offset of the
memory region.
This implementation is more performant than the one using exclusively
the virtqueues. With the virtqueues, the content of the file needs to be
copied to the queues every time the guest is asking to access it.
With the shared memory region, the virtqueues become the control plane
where the libfuse commands are sent to virtiofsd. The data plane is
literally the whole memory region which does not need any extra copy of
the file content. The only penalty is the first time a file is accessed,
it needs to be mapped into the VMM virtual address space.
Another interesting case where this solution will not perform as well as
expected is when a file is larger than the region itself. This means the
file needs to be mapped in several times, but more than that this means
it needs to be remapped every time it's being accessed.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
One of the features of the virtio console device is its size can be
configured and updated. Our first iteration of the console device
implementation is lack of this feature. As a result, it had a
default fixed size which could not be changed. This commit implements
the console config feature and lets us change the console size from
the vmm side.
During the activation of the device, vmm reads the current terminal
size, sets the console configuration accordinly, and lets the driver
know about this configuration by sending an interrupt. Later, if
someone changes the terminal size, the vmm detects the corresponding
event, updates the configuration, and sends interrupt as before. As a
result, the console device driver, in the guest, updates the console
size.
Signed-off-by: A K M Fazla Mehrab <fazla.mehrab.akm@intel.com>
The virtio console device is a console for the communication between
the host and guest userspace. It has two parts: the device and the
driver. The console device is implemented here as a virtio-pci device
to the guest. On the other side, the guest OS expected to have a
character device driver which provides an interface to the userspace
applications.
The console device can have multiple ports where each port has one
transmit queue and one receive queue. The current implementation only
supports one port. For data IO communication, one or more empty
buffers are placed in the receive queue for incoming data, and
outgoing characters are placed in the transmit queue. Details spec
can be found from the following link.
https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.pdf#e7
Apart from the console, for the communication between guest and host,
the Cloud Hypervisor has a legacy serial device implemented. However,
the implementation of a console device lets us be independent of legacy
pin-based interrupts without losing the logs and access to the VM.
Signed-off-by: A K M Fazla Mehrab <fazla.mehrab.akm@intel.com>
This commit introduces the implementation of the virtio-pmem device
based on the pending proposal of the virtio specification here:
https://lists.oasis-open.org/archives/virtio-dev/201903/msg00083.html
It is also based on the kernel patches coming along with the virtio
proposal: https://lkml.org/lkml/2019/6/12/624
And it is based off of the current crosvm implementation found in
devices/src/virtio/pmem.rs relying on commit
bb340d9a94d48514cbe310d05e1ce539aae31264
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The vhost-user-fs or virtio-fs device allows files and directories to
be shared between host and guest. This patch adds the implementation
of this device to the cloud-hypervisor device model.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Most of the code is taken from crosvm(bbd24c5) but is modified to
be adapted to the current VirtioDevice definition and epoll
implementation.
A new command option '--rng' is provided and it gives one the option
to override the entropy source which is /dev/urandom by default.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
In order to provide connectivity through network interface between
host and guest, this patch introduces the virtio-net backend.
This code is based on Firecracker commit
d4a89cdc0bd2867f821e3678328dabad6dd8b767
It is a trimmed down version of the original files as it removes the
rate limiter support. It has been ported to support vm-memory crate
and the epoll handler has been modified in order to run a dedicated
epoll loop from the device itself. This epoll loop runs in its own
dedicated thread.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
If the driver triggers a reset by writing zero into the status register
then reset the underlying device if supported. A device reset also
requires resetting various aspects of the queue.
In order to be able to do a subsequent reactivate it is required to
reclaim certain resources (interrupt and queue EventFDs.) If a device
reset is requested by the driver but the underlying device does not
support it then generate an error as the driver would not be able to
configure it anyway.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Add the BSD and Apache license.
Make all crosvm references point to the BSD license.
Add the right copyrights and identifier to our VMM code.
Add Intel copyright to the vm-virtio and pci crates.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
After the virtio-blk device support has been introduced in the
previous commit, the vmm need to rely on this new device to boot
from disk images instead of initrd built into the kernel.
In order to achieve the proper support of virtio-blk, this commit
had to handle a few things:
- Register an ioevent fd for each virtqueue. This important to be
notified from the virtio driver that something has been written
on the queue.
- Fix the retrieval of 64bits BAR address. This is needed to provide
the right address which need to be registered as the notification
address from the virtio driver.
- Fix the write_bar and read_bar functions. They were both assuming
to be provided with an address, from which they were trying to
find the associated offset. But the reality is that the offset is
directly provided by the Bus layer.
- Register a new virtio-blk device as a virtio-pci device from the
vm.rs code. When the VM is started, it expects a block device to
be created, using this block device as the VM rootfs.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Copied from crosvm 107edb3e with one main modification: VirtioPciDevice
implements BusDevice.
We need this modification because it is the only way for us to be able
to add a VirtioPciDevice to the MMIO bus. Bus insertion takes a
BusDevice. The fact that VirtioPciDevice implements PciDevice which
itself implements BusDevice does not mean that Rust will automatically
downcast a VirtioPciDevice into a BusDevice.
crosvm works around that issue by having the PCI, virtio and BusDevice
implementations in the same crate.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Copied from Firecracker 17a9089d for the queue implementation and from
crosvm 107edb3e for the device Trait. The device trait has some PCI
specific methods hence its crosvm origin.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
