When a virtio device is paused an event is written to the appropriate
"pause" EventFd for the device. This will be noticed by the the device's
epoll_wait(), an atomic bool checked an if true then the thread is
parked(). When resuming the bool is reset and the thread is unpark()ed.
However the event triggering the pause is still in the EventFd so the
epoll_wait() will continue to return but because the boolean is not set
the thread will not be park()ed but instead we will busy loop around an
event that is not being consumed.
The solution is to drain the "pause" EventFd when the event is first
received and thus the epoll_wait() will only return for the pause event
once. This resolves the infinite epoll_wait() wake-ups.
Fixes: #869
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Relying on the latest vm-memory version, including the freshly
introduced structure GuestMemoryAtomic, this patch replaces every
occurrence of Arc<ArcSwap<GuestMemoryMmap> with
GuestMemoryAtomic<GuestMemoryMmap>.
The point is to rely on the common RCU-like implementation from
vm-memory so that we don't have to do it from Cloud-Hypervisor.
Fixes#735
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
By detecting if an existing tap interface supports multiqueue, we now
have the information to determine if the command line parameters
regarding the number of queues is correct.
Fixes#738
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit introduces a clear definition of the virtio-net
configuration structure, allowing both vhost-user-net and
virtio-net devices to rely on it.
This makes the code more readable for developers.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Update the common part in net_util.rs under vm-virtio to add mq
support, meanwhile enable mq for virtio-net device, vhost-user-net
device and vhost-user-net backend. Multiple threads will be created,
one thread will be responsible to handle one queue pair separately.
To gain the better performance, it requires to have the same amount
of vcpus as queue pair numbers defined for the net device, due to
the cpu affinity.
Multiple thread support is not added for vhost-user-net backend
currently, it will be added in future.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
Add support to allow VMMs to open the same tap device many times, it will
create multiple file descriptors meanwhile.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
Current guest kernel will check the oneline cpu count, in principle,
if the online cpu count is not smaller than the number of queue pairs
VMM reported, the net packets could be put/get to all the virtqueues,
otherwise, only the number of queue pairs that match the oneline cpu
count will have packets work with. guest kernel will send command
through control queue to tell VMMs the actual queue pair numbers which
it could currently play with. Add mq process in control queue handling
to get the queue pair number, VMM will verify if it is in a valid range,
nothing else but this.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
As virtio spec 1.1 said, the driver uses the control queue
to send commands to manipulate various features of the devices,
such as VIRTIO_NET_F_MQ which is required by multiple queue
support. Here add the control queue handling process.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
There are some common logic shared among virtio-net device, vhost-user-net
device and vhost-user-net backend, abstract those parts into net_util.rs
to improve code maintainability and readability.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
