The vhost-user implementation was always passing the maximum size
supported by the virtqueues to the backend, but this is obviously wrong
as it must pass the size being set by the driver running in the guest.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The 32 or 64 bits type for the memory BAR was not set correctly. This
patch ensure the right type is applied to the BAR.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
If we expect the vhost-user-blk device to be used for booting a VMM
along with the firmware, then need the device to support being reset.
In the vhost-user context, this means the backend needs to be informed
the vrings are disabled and stopped, and the owner needs to be reset
too.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In vhost-user-blk, only WCE value can be set back to device in
guest kernel like
echo "write through" > /sys/block/vda/cache_type
So write_config() will only set WCE value from guest kernel to
vhost user side.
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Since config space in vhost-user-blk are mostly from backend
device, this change will get config space info from backend
by vhost-user protocol.
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
vhost-user-blk has better performance than virtio-blk, so we need
add vhost-user-blk support with SPDK in Rust-based VMMs.
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Now that virtio-bindings is a crate part of the rust-vmm project, we
want to rely on this one instead of the local one we had so far.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Currently all devices and guest memory share the same 64GiB
allocation. With guest memory working upwards and devices working
downwards. This creates issues if you want to either have a VM with a
large amount of memory or want to have devices with a large allocation
(e.g. virtio-pmem.)
As it is possible for the hypervisor to place devices anywhere in its
address range it is required for simplistic users like the firmware to
set up an identity page table mapping across the full range. Currently
the hypervisor sets up an identify mapping of 1GiB which the firmware
extends to 64GiB to match the current address space size of the
hypervisor.
A simpler solution is to place the device needed for booting with the
firmware (virtio-block) inside the 32-bit memory hole. This allows the
firmware to easily access the block device and paves the way for
increasing the address space beyond the current 64GiB limit.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Derived from the crosvm code at 5656c124af2bb956dba19e409a269ca588c685e3
and adapted to work within cloud-hypervisor:
Main differences:
* Interrupt handling is done via a VirtioInterrupt turned into a
devices::Interrupt
* GuestMemory -> GuestMemoryMmap
* Differences in read/write for BusDevice
* Different crates for EventFd and GuestAddress
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This unit testing porting effort is based off of Firecracker commit
1e1cb6f8f8003e0bdce11d265f0feb23249a03f6
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This is the last step connecting the dots between the virtio-vsock
device and the bulk of the logic hosted in the unix and csm modules.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit relies on the new vsock::unix module to create the backend
that will be used from the virtio-vsock device.
The concept of backend is interesting here as it would allow for a vhost
kernel backend to be plugged if that was needed someday.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This code porting is based off of Firecracker commit
1e1cb6f8f8003e0bdce11d265f0feb23249a03f6
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This code porting is based off of Firecracker commit
1e1cb6f8f8003e0bdce11d265f0feb23249a03f6
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
There is a lot of code related to this virtio-vsock hybrid
implementation, that's why it's better to keep it under its
own module.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This is the first commit introducing the support for virtio-vsock.
This is based off of Firecracker commit
1e1cb6f8f8003e0bdce11d265f0feb23249a03f6
Fixes#102
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Regarding vhost-user-net, there are features in avail_features
and acked_features, like VIRTIO_NET_F_MAC which is required by
driver and device to transfer mac address through config space,
but not needed by backend, like ovs+dpdk, so it's necessary to
adjust backend_features based on acked_features before calling
set_features() API.
This fix is to record backend_features in vhost-user-net to avoid
requesting it twice.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
New event is added in VhostUserEpollHandler for vhost-user fs,
but the total event count is not update accordingly. Fix the
issue and refactor the event data setting for new event
expansion in the future.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
At this point in the code, the acked features have been provided by the
guest and they can be set back to the backend. There's no need to
retrieve one more time the backend features for this purpose.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
As mentioned in the vhost-user specification, each ring is initialized
in a stopped state. This means each ring should be enabled only after
it has been correctly initialized.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The available features are masked with the backend features, therefore
the available features should be the one used when calling into
set_features() API.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to factorize the code between vhost-user-net and virtio-fs one
step further, this patch extends the vhost-user handler implementation
to support slave requests.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch factorizes the existing virtio-fs code by relying onto the
common code part of the vhost_user module in the vm-virtio crate.
In details, it factorizes the vhost-user setup, and reuses the error
types defined by the module instead of defining its own types.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
vhost-user-net introduced a new module vhost_user inside the vm-virtio
crate. Because virtio-fs is actually vhost-user-fs, it belongs to this
new module and needs to be moved there.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
vhost-user framwork could provide good performance in data intensive
scenario due to the memory sharing mechanism. Implement vhost-user-net
device to get the benefit for Rust-based VMMs network.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
By making the registration functions immutable, this patch prevents from
self borrowing issues with the RwLock on self.mem.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Following the refactoring of the code allowing multiple threads to
access the same instance of the guest memory, this patch goes one step
further by adding RwLock to it. This anticipates the future need for
being able to modify the content of the guest memory at runtime.
The reasons for adding regions to an existing guest memory could be:
- Add virtio-pmem and virtio-fs regions after the guest memory was
created.
- Support future hotplug of devices, memory, or anything that would
require more memory at runtime.
Because most of the time, the lock will be taken as read only, using
RwLock instead of Mutex is the right approach.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The VMM guest memory was cloned (copied) everywhere the code needed to
have ownership of it. In order to clean the code, and in anticipation
for future support of modifying this guest memory instance at runtime,
it is important that every part of the code share the same instance.
Because VirtioDevice implementations need to have access to it from
different threads, that's why Arc must be used in this case.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When there are no available descriptors in the queue (observed when the
network interface hasn't been brought up by the kernel) stop waiting for
notifications that the TAP fd should be read from.
This avoids a situation where the TAP device has data avaiable and wakes
up the virtio-net thread only for the virtio-net thread not read that
data as it has nowhere to put it.
When there are descriptors available in the queue then we resume waiting
for the epoll event on the TAP fd.
This bug demonstrated itself as 100% CPU usage for cloud-hypervisor
binary prior to the guest network interface being brought up. The
solution was inspired by the Firecracker virtio-net code.
Fixes: #208
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Latest clippy version complains about our existing code for the
following reasons:
- trait objects without an explicit `dyn` are deprecated
- `...` range patterns are deprecated
- lint `clippy::const_static_lifetime` has been renamed to
`clippy::redundant_static_lifetimes`
- unnecessary `unsafe` block
- unneeded return statement
All these issues have been fixed through this patch, and rustfmt has
been run to cleanup potential formatting errors due to those changes.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
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>
When the cache_size parameter from virtio-fs device is not empty, the
VMM creates a dedicated memory region where the shared files will be
memory mapped by the virtio-fs device.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In the context of shared memory regions, they could not be present for
most of the virtio devices. For this reason, we prefer dedicate a BAR
for the shared memory regions.
Another reason is that memory regions, if there are several, can be
allocated all at once as a contiguous region, which then can be used as
its own BAR. It would be more complicated to try to allocate the BAR 0
holding the regular information about the virtio-pci device along with
the shared memory regions.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch cleans up the VirtioDevice trait. Since some function are PCI
specific and since they are not even used, it makes sense to remove them
from the trait definition.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the newly added SharedMemoryConfig capability to the virtio
specification, and based on the fact that it is not tied to the type of
transport (pci or mmio), we can create as part of the VirtioDevice trait
a new method that will provide the shared memory regions associated with
the device.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the latest version of the virtio specification, the structure
virtio_pci_cap has been updated and a new structure virtio_pci_cap64 has
been introduced.
virtio_pci_cap now includes a field "id" that does not modify the
existing structure size since there was a 3 bytes reserved field
already there. The id is used in the context of shared memory regions
which need to be identified since there could be more than one of this
kind of capability.
virtio_pci_cap64 is a new structure that includes virtio_pci_cap and
extends it to allow 64 bits offsets and 64 bits region length. This is
used in the context of shared memory regions capability, as we might need
to describe regions of 4G or more, that could be placed at a 4G offset
or more in the associated BAR.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The length of the PCI capability as it is being calculated by the guest
was not accurate since it was not including the implicit 2 bytes offset.
The reason for this offset is that the structure itself does not contain
the capability ID (1 byte) and the next capability pointer (1 byte), but
the structure exposed through PCI config space does include those bytes.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The numbr of bytes read was being incorrectly increased by the potential
length of the end of the sliced data rather than the number of bytes
that was in the range. This caused a panic when the the network was
under load by using iperf.
It's important to note that in the Firecracker code base the function
that read_slice() returns the number of bytes read which is used to
increment this counter. The VM memory version however only returns the
empty unit "()".
Fixes: #166
Signed-off-by: Rob Bradford <robert.bradford@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>
Relying on the newly added MSI-X helper, the interrupt callback checks
the interrupts are enabled on the device before to try triggering the
interrupt.
Fixes#156
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The structure of the vmm-sys-util crate has changed with lots of code
moving to submodules.
This change adjusts the use of the imported structs to reference the
submodules.
Fixes: #145
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Update all dependencies with "cargo upgrade" with the exception of
vmm-sys-utils which needs some extra porting work.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The existing code taking care of the epoll loop was too restrictive as
it was propagating the error returned from the epoll_wait() syscall, no
matter what was the error. This causes the epoll loop to be broken,
leading to a non-functional virtio device.
This patch enforces the parsing of the returned error and prevent from
the error propagation in case it is EINTR, which stands for Interrupted.
In case the epoll loop is interrupted, it is appropriate to retry.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
As per the VIRTIO specification, every virtio device configuration can
be updated while the guest is running. The guest needs to be notified
when this happens, and it can be done in two different ways, depending
on the type of interrupt being used for those devices.
In case the device uses INTx, the allocated IRQ pin is shared between
queues and configuration updates. The way for the guest to differentiate
between an interrupt meant for a virtqueue or meant for a configuration
update is tied to the value of the ISR status field. This field is a
simple 32 bits bitmask where only bit 0 and 1 can be changed, the rest
is reserved.
In case the device uses MSI/MSI-X, the driver should allocate a
dedicated vector for configuration updates. This case is much simpler as
it only requires the device to send the appropriate MSI vector.
The cloud-hypervisor codebase was not supporting the update of a virtio
device configuration. This patch extends the existing VirtioInterrupt
closure to accept a type that can be Config or Queue, so that based on
this type, the closure implementation can make the right choice about
which interrupt pin or vector to trigger.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@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>
