From 28770ff935bce723c5799d292bc788770b69a733 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 9 Jun 2021 08:46:53 -0700 Subject: vhost: Distinguish errors in vhost_backend_init() Instead of just returning 0/-1 and letting the caller make up a meaningless error message, add an Error parameter to allow reporting the real error and switch to 0/-errno so that different kind of errors can be distinguished in the caller. Specifically, in vhost-user, EPROTO is used for all errors that relate to the connection itself, whereas other error codes are used for errors relating to the content of the connection. This will allow us later to automatically reconnect when the connection goes away, without ending up in an endless loop if it's a permanent error in the configuration. Signed-off-by: Kevin Wolf Message-Id: <20210609154658.350308-3-kwolf@redhat.com> Reviewed-by: Stefano Garzarella Reviewed-by: Raphael Norwitz Signed-off-by: Kevin Wolf --- hw/virtio/vhost-user.c | 41 +++++++++++++++++++++-------------------- 1 file changed, 21 insertions(+), 20 deletions(-) (limited to 'hw/virtio/vhost-user.c') diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index ee57abe..024cb20 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -1856,7 +1856,8 @@ static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier, return 0; } -static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) +static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque, + Error **errp) { uint64_t features, protocol_features, ram_slots; struct vhost_user *u; @@ -1871,7 +1872,7 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) err = vhost_user_get_features(dev, &features); if (err < 0) { - return err; + return -EPROTO; } if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) { @@ -1880,7 +1881,7 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES, &protocol_features); if (err < 0) { - return err; + return -EPROTO; } dev->protocol_features = @@ -1891,14 +1892,14 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) dev->protocol_features &= ~(1ULL << VHOST_USER_PROTOCOL_F_CONFIG); } else if (!(protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_CONFIG))) { - error_report("Device expects VHOST_USER_PROTOCOL_F_CONFIG " - "but backend does not support it."); - return -1; + error_setg(errp, "Device expects VHOST_USER_PROTOCOL_F_CONFIG " + "but backend does not support it."); + return -EINVAL; } err = vhost_user_set_protocol_features(dev, dev->protocol_features); if (err < 0) { - return err; + return -EPROTO; } /* query the max queues we support if backend supports Multiple Queue */ @@ -1906,12 +1907,12 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM, &dev->max_queues); if (err < 0) { - return err; + return -EPROTO; } } if (dev->num_queues && dev->max_queues < dev->num_queues) { - error_report("The maximum number of queues supported by the " - "backend is %" PRIu64, dev->max_queues); + error_setg(errp, "The maximum number of queues supported by the " + "backend is %" PRIu64, dev->max_queues); return -EINVAL; } @@ -1920,9 +1921,9 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) VHOST_USER_PROTOCOL_F_SLAVE_REQ) && virtio_has_feature(dev->protocol_features, VHOST_USER_PROTOCOL_F_REPLY_ACK))) { - error_report("IOMMU support requires reply-ack and " - "slave-req protocol features."); - return -1; + error_setg(errp, "IOMMU support requires reply-ack and " + "slave-req protocol features."); + return -EINVAL; } /* get max memory regions if backend supports configurable RAM slots */ @@ -1932,15 +1933,15 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) } else { err = vhost_user_get_max_memslots(dev, &ram_slots); if (err < 0) { - return err; + return -EPROTO; } if (ram_slots < u->user->memory_slots) { - error_report("The backend specified a max ram slots limit " - "of %" PRIu64", when the prior validated limit was %d. " - "This limit should never decrease.", ram_slots, - u->user->memory_slots); - return -1; + error_setg(errp, "The backend specified a max ram slots limit " + "of %" PRIu64", when the prior validated limit was " + "%d. This limit should never decrease.", ram_slots, + u->user->memory_slots); + return -EINVAL; } u->user->memory_slots = MIN(ram_slots, VHOST_USER_MAX_RAM_SLOTS); @@ -1958,7 +1959,7 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque) if (dev->vq_index == 0) { err = vhost_setup_slave_channel(dev); if (err < 0) { - return err; + return -EPROTO; } } -- cgit v1.1