The driver CQ event management is done by non vhost library thread,
either the dpdk host thread or the internal vDPA driver thread.
When a queue is updated the CQ may be destroyed and created by the vhost
library thread via the queue state operation.
When the queue update feature was added, it didn't synchronize the CQ
management to the queue update what may cause invalid memory access.
Add the aforementioned synchronization by a new per device configuration
mutex.
Fixes: c47d6e83334e ("vdpa/mlx5: support queue update")
Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Vdpa example failed on vq setup, the api to get event queue of specified
core failed.
Internal api devx_query_eqn expects index of event queue vectors, no
need to use cpu id. As the doorbell handling thread is per device, it's
sufficient to use default event queue.
This patch uses the default id(0) as event queue index.
Fixes: 8395927cdfaf ("vdpa/mlx5: prepare HW queues")
Cc: stable@dpdk.org
Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Vdpa device failed to initialize 2nd VQ during setup. From FW syndrome,
unsupported CQE size was specified in CQ initialization attributes.
The unsupported CQE size comes from uninitialized stack struct data, and
the struct has new fields defined recently which are not initialized in
vdpa code.
This patch initializes cq creation attributes with zero to avoid such
random data.
Fixes: 79a7e409a2f6 ("common/mlx5: prepare support of packet pacing")
Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
The issue is relevant only for the timer event modes: 0 and 1.
When the HW finishes to consume a burst of the guest Rx descriptors,
it creates a CQE in the CQ.
When traffic stops, the mlx5 driver arms the CQ to get a notification
when a specific CQE index is created - the index to be armed is the
next CQE index which should be polled by the driver.
The mlx5 driver configured the kernel driver to send notification to
the guest callfd in the same time of the armed CQE event.
It means that the guest was notified only for each first CQE in a
poll cycle, so if the driver polled CQEs of all the virtio queue
available descriptors, the guest was not notified again for the rest
because there was no any new CQE to trigger the guest notification.
Hence, the Rx queues might be stuck when the guest didn't work with
poll mode.
Remove prior kernel notification, and do manual notification after CQ
polling.
Fixes: a9dd7275a149 ("vdpa/mlx5: optimize notification events")
Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Xueming Li <xuemingl@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
The CQ polling is necessary in order to manage guest notifications when
the guest doesn't work with poll mode (callfd != -1).
The CQ polling scheduling method can affect the host CPU utilization and
the traffic bandwidth.
Define 3 modes to control the CQ polling scheduling:
1. A timer thread which automatically adjusts its delays to the coming
traffic rate.
2. A timer thread with fixed delay time.
3. Interrupts: Each CQE burst arms the CQ in order to get an interrupt
event in the next traffic burst.
When traffic becomes off, mode 3 is taken automatically.
The interrupt management takes a lot of CPU cycles but forward traffic
event to the guest very fast.
Timer thread save the interrupt overhead but may add delay for the guest
notification.
Add device arguments to control on the mode.
Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
The vDPA driver uses a CQ in order to know when traffic works were
completed by the HW.
Each traffic burst completion adds a CQE to the CQ.
When the vDPA driver detects CQEs in the CQ, it triggers the guest
notification for the corresponding queue and consumes all of them.
There is collapse feature in the HW that configures the HW to write all
the CQEs in the first entry of the CQ.
Using this feature, the vDPA driver can read only the first CQE,
validate that the completion counter inside the CQE was changed and if
so, to notify the guest.
Use CQ collapse feature in order to improve the poll utilization.
Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
When the virtio guest driver doesn't work with poll mode, the driver
creates event mechanism in order to schedule completion notifications
for each virtq burst traffic.
When traffic comes to a virtq, a CQE will be added to the virtq CQ by
the FW.
The driver requests interrupt for the next CQE index, and when interrupt
is triggered, the driver polls the CQ and notifies the guest by virtq
callfd writing.
According to the described method, the interrupts will be triggered for
each burst of traffic. The burst size depends on interrupt latency.
Interrupts management takes a lot of CPU cycles and using it for each
traffic burst takes big portion of CPU capacity.
When traffic is on, using timer for CQ poll scheduling instead of
interrupts saves a lot of CPU cycles.
Move CQ poll scheduling to be done by timer in case of running traffic.
Request interrupts only when traffic is off.
The timer scheduling management is done by a new dedicated thread uses
a usleep command.
Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
When the HW finishes to consume the guest Rx descriptors, it creates a
CQE in the CQ.
The mlx5 driver arms the CQ to get notifications when a specific CQE
index is created - the index to be armed is the next CQE index which
should be polled by the driver.
The mlx5 driver configured the kernel driver to send notification to the
guest callfd in the same time it arrives to the mlx5 driver.
It means that the guest was notified only for each first CQE in a poll
cycle, so if the driver polled CQEs of all the virtio queue available
descriptors, the guest was not notified again for the rest because
there was no any new cycle for polling.
Hence, the Rx queues might be stuck when the guest didn't work with
poll mode.
Move the guest notification to be after the driver consumes all the
SW own CQEs.
By this way, guest will be notified only after all the SW CQEs are
polled.
Also init the CQ to be with HW owner in the start.
Fixes: 8395927cdfaf ("vdpa/mlx5: prepare HW queues")
Signed-off-by: Matan Azrad <matan@mellanox.com>
The completion event mechanism should work only if at least one of the
virtqs has valid callfd to be notified on.
When all the virtqs works with poll mode, the event mechanism should not
be configured.
The driver didn't take it into account and crashed in the above case.
Do not configure event interrupt when all the virtqs are in poll mode.
Fixes: 8395927cdfaf ("vdpa/mlx5: prepare HW queues")
Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
The mlx5 vDPA driver manages QP and CQ in order to forward the HW event
to the guest by the callfd file descriptor for each virtq.
The driver arms the CQ for the next CQE index that should be
completed by the HW in order to create completion event.
In the SW completion event handler, the driver arms the CQ again for the
next index,
The CQE index in the CQ doorbell and in the CQ doorbell record was
masked incorrectly with the CQ size mask while it should be masked only
with 0xFFFFFF mask.
Remove the CQ size mask, stay only with 0xFFFFFF mask.
Fixes: 8395927cdfaf ("vdpa/mlx5: prepare HW queues")
Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Maxime Coquelin <maxime.coquelin@redhat.com>
As an arrangement to the vitrio queues creation, a 2 QPs and CQ may be
created for the virtio queue.
The design is to trigger an event for the guest and for the vdpa driver
when a new CQE is posted by the HW after the packet transition.
This patch add the basic operations to create and destroy the above HW
objects and to trigger the CQE events when a new CQE is posted.
Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
