On 4/11/22 13:00, David Marchand wrote:
This change simply annotates existing paths of the code leading to manipulations of the IOTLB r/w locks. clang does not support conditionally held locks, so always take iotlb locks regardless of VIRTIO_F_IOMMU_PLATFORM feature. vdpa and vhost_crypto code are annotated though they end up not taking a IOTLB lock and have been marked with a FIXME. Signed-off-by: David Marchand <david.march...@redhat.com> --- lib/vhost/iotlb.h | 8 +++++++ lib/vhost/vdpa.c | 1 + lib/vhost/vhost.c | 11 +++++---- lib/vhost/vhost.h | 22 +++++++++++++----- lib/vhost/vhost_crypto.c | 7 ++++++ lib/vhost/virtio_net.c | 49 ++++++++++++++++++++++++++++++---------- 6 files changed, 75 insertions(+), 23 deletions(-)
I agree with the change. I don't expect performance impact of taking the lock unconditionally, because there won't be cache line sharing since it is per-vq lock and the locking cost will be offset by removing the feature check. Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com> Thanks, Maxime
