This is the same workaround as commit 523b018dde3b765, which was lost with libvhost-user transition in commit e10e798c85c2331.
Signed-off-by: Marc-André Lureau <[email protected]> --- contrib/libvhost-user/libvhost-user.h | 5 +++++ contrib/libvhost-user/libvhost-user.c | 13 +++++++++++++ 2 files changed, 18 insertions(+) diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h index 53ef222c0b..aca71717c1 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -132,6 +132,7 @@ typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t features); typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg, int *do_reply); typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started); +typedef bool (*vu_queue_resume_to_used_cb) (VuDev *dev, int qidx); typedef struct VuDevIface { /* called by VHOST_USER_GET_FEATURES to get the features bitmask */ @@ -148,6 +149,10 @@ typedef struct VuDevIface { vu_process_msg_cb process_msg; /* tells when queues can be processed */ vu_queue_set_started_cb queue_set_started; + /* If the queue must be resumed to vring.used->idx. */ + /* This can help to support resuming on unmanaged exit/crash when + * the slave/driver processes elements in order. */ + vu_queue_resume_to_used_cb queue_resume_to_used; } VuDevIface; typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx); diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index 35fa0c5e56..36439caed6 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -521,6 +521,19 @@ vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg) vq->used_idx = vq->vring.used->idx; + if (vq->last_avail_idx != vq->used_idx) { + bool resume = dev->iface->queue_resume_to_used && + dev->iface->queue_resume_to_used(dev, index); + + DPRINT("Last avail index != used index: %u != %u%s\n", + vq->last_avail_idx, vq->used_idx, + resume ? ", resuming" : ""); + + if (resume) { + vq->shadow_avail_idx = vq->last_avail_idx = vq->used_idx; + } + } + return false; } -- 2.14.1.146.gd35faa819
