Commit 35480cbf authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Michael S. Tsirkin
Browse files

libvhost-user: support resuming vq->last_avail_idx based on used_idx 



This is the same workaround as commit 523b018d, which was lost
with libvhost-user transition in commit e10e798c.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 0b4a7751

contrib/libvhost-user/libvhost-user.c

+13 −0
Original line number Diff line number Diff line
@@ -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;

}

contrib/libvhost-user/libvhost-user.h

+7 −0
Original line number Diff line number Diff line
@@ -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);