IOTLB entries contain the host virtual address of the guest
pages. When receiving a new VHOST_USER_SET_MEM_TABLE request,
the previous regions get unmapped, so the IOTLB entries, if any,
will be invalid. It does cause the vhost-user process to
segfault.
This patch introduces a new function to flush the IOTLB cache,
and call it as soon as the backend handles a VHOST_USER_SET_MEM
request.
Fixes: 69c90e98f483 ("vhost: enable IOMMU support")
Cc: stable@dpdk.org
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
In case vhost_user_iotlb_miss returns an error, the pending IOTLB
entry has to be removed from the list as no IOTLB update will be
received.
Fixes: fed67a20ac94 ("vhost: introduce guest IOVA to backend VA helper")
Cc: stable@dpdk.org
Suggested-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
In the unlikely case the IOTLB memory pool runs out of memory,
an issue may happen if all entries are used by the IOTLB cache,
and an IOTLB miss happen. If the iotlb pending list is empty,
then no memory is freed and allocation fails a second time.
This patch fixes this by doing an IOTLB cache random evict if
the IOTLB pending list is empty, ensuring the second allocation
try will succeed.
In the same spirit, the opposite is done when inserting an
IOTLB entry in the IOTLB cache fails due to out of memory. In
this case, the IOTLB pending is flushed if the IOTLB cache is
empty to ensure the new entry can be inserted.
Fixes: d012d1f293f4 ("vhost: add IOTLB helper functions")
Fixes: f72c2ad63aeb ("vhost: add pending IOTLB miss request list and helpers")
Cc: stable@dpdk.org
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
In case of NUMA reallocation, virtqueue's iotlb list is broken,
has its head changes but first iotlb entry in the list still points
to the previous head pointer.
Also, in case of reallocation, we want the IOTLB cache mempool to be
on the new socket.
This patch perform a full re-init of the IOTLB cache when mempool
already exists, and calls the IOTLB cache init function in case
the virtqueue is being reallocated on a new socket.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
When compiling with clang extra warning flags, such as used by default with
meson, a warning is given in iotlb.c:
lib/librte_vhost/iotlb.c:318:6: warning:
variable 'socket' is used uninitialized whenever
'if' condition is false [-Wsometimes-uninitialized]
This is a false positive, as the socket value will be initialized by the
call to get_mempolicy in the case where the NUMA build-time flag is set,
and in cases where it is not set, "if (ret)" will always be true as ret is
initialized to -1 and never changed.
However, this is not immediately obvious, and is perhaps a little fragile,
as it will break if other code using ret is subsequently added above the
call to get_mempolicy by someone unaware of this subtle dependency.
Therefore, we can fix the warning and making the code more robust by
explicitly initializing socket to zero, and moving the extra condition
check on the return from get_mempolicy() into the #ifdef
Fixes: d012d1f293f4 ("vhost: add IOTLB helper functions")
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
In order to be able to handle other ports or queues while waiting
for an IOTLB miss reply, a pending list is created so that waiter
can return and restart later on with sending again a miss request.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yliu@fridaylinux.org>
