From 35480cbfcb73143af66c8de4b444d686a46c2e88 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Tue, 29 Aug 2017 17:27:50 +0200 Subject: [PATCH] libvhost-user: support resuming vq->last_avail_idx based on used_idx MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is the same workaround as commit 523b018dde3b765, which was lost with libvhost-user transition in commit e10e798c85c2331. Signed-off-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- contrib/libvhost-user/libvhost-user.c | 13 +++++++++++++ contrib/libvhost-user/libvhost-user.h | 7 +++++++ 2 files changed, 20 insertions(+) diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index 35fa0c5e56..d27d6303db 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_is_processed_in_order && + dev->iface->queue_is_processed_in_order(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; } diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h index 53ef222c0b..4021f1124e 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_is_processed_in_order_cb) (VuDev *dev, int qidx); typedef struct VuDevIface { /* called by VHOST_USER_GET_FEATURES to get the features bitmask */ @@ -148,6 +149,12 @@ 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 is processed in order, in which case it will be + * resumed to vring.used->idx. This can help to support resuming + * on unmanaged exit/crash. + */ + vu_queue_is_processed_in_order_cb queue_is_processed_in_order; } VuDevIface; typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);