rte_vhost has rejected a patch with this feature, so
we implement it using the external rte_vhost msg handling
hooks directly in SPDK.
Change-Id: Ib072fc19b921fe0fa01c7f4892e60430232e3a1c
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/447025
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
rte_vhost requires all queues to be fully initialized
in order to start I/O processing. This behavior is not
compliant with the vhost-user specification and doesn't
work with QEMU 2.12+, which will only initialize 1 I/O
queue for the SeaBIOS boot. Theoretically, we should
start polling each virtqueue individually after
receiving its SET_VRING_KICK message, but rte_vhost is
not designed to poll individual queues. So we use
a workaround to detect when a vhost session could be
potentially at that SeaBIOS stage and we mark it to
start polling as soon as its first virtqueue gets
initialized. This doesn't hurt any non-QEMU vhost slaves
and allows QEMU 2.12+ to boot correctly. SET_FEATURES
could be sent at any time, but QEMU will send it at
least once on SeaBIOS initialization - whenever
powered-up or rebooted.
Vhost sessions are still mostly started/stopped from
within rte_vhost callbacks, but now there's additional
concept of "forced" polling, in which SPDK starts
sessions manually, while rte_vhost still thinks the
sessions are stopped. This can potentially lead to cases
where a session is "started" twice, or gets destroyed
while it's still being polled (by force). Those cases
also need to be handled within this patch.
Change-Id: I70636d63e27914906ddece59cec34f1dd37ec5cd
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/446086
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
VHOST_USER_SET_VRING_CALL invalidates the previous
file descriptor that SPDK may be using on a different
thread. The new descriptor is stored inside rte_vhost
internals and is queryable with rte_vhost APIs, but
those APIs are too expensive to be called every tick
or every time we need to use that fd. Hence, we will
now stop the entire vhost session before processing
SET_VRING_CALL msg and restart it right after. SPDK
will query the most recent call descriptor on session
start.
We do not necessarily have to stop the device - just
letting the session know that its callfd has changed
would be enough. That's an area for future optimization.
Change-Id: Idccf56fccd21ad0d3c2307eefee7bf35e350fec6
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/447639
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
DPDK 19.05+ gives us an ability to pre or post-process
any single vhost-user message. The user can either perform
additional actions upon some generic events, or can
implement handling for brand new message types that
rte_vhost doesn't even know about.
In order to smoothly switch to the upstream rte_vhost
and drop our internal copy, we introduce an SPDK wrapper
function to register SPDK-specific message handlers. For
DPDK 19.05+ this will use the new rte_vhost API to
register those message handlers, and for older DPDKs
this function simply won't do anything - as w assume the
internal rte_copy already contains all the necessary
changes and does not need any "external" hooks.
For now we use the message handlers to stop the vhost
device and wait for any pending DMA ops before letting
rte_vhost to process the SET_MEM_TABLE message and unmap
the current shared memory.
Change-Id: Ic0fefa9174254627cb3fc0ed30ab1e54be4dd654
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/446085
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
