diff options
| -rw-r--r-- | Documentation/lguest/lguest.c | 62 | ||||
| -rw-r--r-- | drivers/block/virtio_blk.c | 6 | ||||
| -rw-r--r-- | drivers/lguest/lguest_device.c | 14 | ||||
| -rw-r--r-- | drivers/net/virtio_net.c | 5 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 12 | ||||
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 11 | ||||
| -rw-r--r-- | include/linux/virtio.h | 5 | ||||
| -rw-r--r-- | include/linux/virtio_config.h | 4 |
8 files changed, 87 insertions, 32 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 8ff2d8b..0f23d67 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -193,6 +193,13 @@ static void *_convert(struct iovec *iov, size_t size, size_t align, #define le32_to_cpu(v32) (v32) #define le64_to_cpu(v64) (v64) +/* The device virtqueue descriptors are followed by feature bitmasks. */ +static u8 *get_feature_bits(struct device *dev) +{ + return (u8 *)(dev->desc + 1) + + dev->desc->num_vq * sizeof(struct lguest_vqconfig); +} + /*L:100 The Launcher code itself takes us out into userspace, that scary place * where pointers run wild and free! Unfortunately, like most userspace * programs, it's quite boring (which is why everyone likes to hack on the @@ -914,21 +921,58 @@ static void enable_fd(int fd, struct virtqueue *vq) write(waker_fd, &vq->dev->fd, sizeof(vq->dev->fd)); } +/* Resetting a device is fairly easy. */ +static void reset_device(struct device *dev) +{ + struct virtqueue *vq; + + verbose("Resetting device %s\n", dev->name); + /* Clear the status. */ + dev->desc->status = 0; + + /* Clear any features they've acked. */ + memset(get_feature_bits(dev) + dev->desc->feature_len, 0, + dev->desc->feature_len); + + /* Zero out the virtqueues. */ + for (vq = dev->vq; vq; vq = vq->next) { + memset(vq->vring.desc, 0, + vring_size(vq->config.num, getpagesize())); + vq->last_avail_idx = 0; + } +} + /* This is the generic routine we call when the Guest uses LHCALL_NOTIFY. */ static void handle_output(int fd, unsigned long addr) { struct device *i; struct virtqueue *vq; - /* Check each virtqueue. */ + /* Check each device and virtqueue. */ for (i = devices.dev; i; i = i->next) { + /* Notifications to device descriptors reset the device. */ + if (from_guest_phys(addr) == i->desc) { + reset_device(i); + return; + } + + /* Notifications to virtqueues mean output has occurred. */ for (vq = i->vq; vq; vq = vq->next) { - if (vq->config.pfn == addr/getpagesize()) { - verbose("Output to %s\n", vq->dev->name); - if (vq->handle_output) - vq->handle_output(fd, vq); + if (vq->config.pfn != addr/getpagesize()) + continue; + + /* Guest should acknowledge (and set features!) before + * using the device. */ + if (i->desc->status == 0) { + warnx("%s gave early output", i->name); return; } + + if (strcmp(vq->dev->name, "console") != 0) + verbose("Output to %s\n", vq->dev->name); + if (vq->handle_output) + vq->handle_output(fd, vq); + return; } } @@ -1074,10 +1118,11 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, vq->vring.used->flags = VRING_USED_F_NO_NOTIFY; } -/* The virtqueue descriptors are followed by feature bytes. */ +/* The first half of the feature bitmask is for us to advertise features. The + * second half if for the Guest to accept features. */ static void add_feature(struct device *dev, unsigned bit) { - u8 *features; + u8 *features = get_feature_bits(dev); /* We can't extend the feature bits once we've added config bytes */ if (dev->desc->feature_len <= bit / CHAR_BIT) { @@ -1085,9 +1130,6 @@ static void add_feature(struct device *dev, unsigned bit) dev->desc->feature_len = (bit / CHAR_BIT) + 1; } - features = (u8 *)(dev->desc + 1) - + dev->desc->num_vq * sizeof(struct lguest_vqconfig); - features[bit / CHAR_BIT] |= (1 << (bit % CHAR_BIT)); } diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 54a8017..6143337 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -264,12 +264,16 @@ static void virtblk_remove(struct virtio_device *vdev) struct virtio_blk *vblk = vdev->priv; int major = vblk->disk->major; + /* Nothing should be pending. */ BUG_ON(!list_empty(&vblk->reqs)); + + /* Stop all the virtqueues. */ + vdev->config->reset(vdev); + blk_cleanup_queue(vblk->disk->queue); put_disk(vblk->disk); unregister_blkdev(major, "virtblk"); mempool_destroy(vblk->pool); - /* There should be nothing in the queue now, so no need to shutdown */ vdev->config->del_vq(vblk->vq); kfree(vblk); } diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index ced5b44..84f85e2 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -54,7 +54,7 @@ struct lguest_device { * * The configuration information for a device consists of one or more * virtqueues, a feature bitmaks, and some configuration bytes. The - * configuration bytes don't really matter to us: the Launcher set them up, and + * configuration bytes don't really matter to us: the Launcher sets them up, and * the driver will look at them during setup. * * A convenient routine to return the device's virtqueue config array: @@ -139,9 +139,20 @@ static u8 lg_get_status(struct virtio_device *vdev) static void lg_set_status(struct virtio_device *vdev, u8 status) { + BUG_ON(!status); to_lgdev(vdev)->desc->status = status; } +/* To reset the device, we (ab)use the NOTIFY hypercall, with the descriptor + * address of the device. The Host will zero the status and all the + * features. */ +static void lg_reset(struct virtio_device *vdev) +{ + unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices; + + hcall(LHCALL_NOTIFY, (max_pfn<<PAGE_SHIFT) + offset, 0, 0); +} + /* * Virtqueues * @@ -279,6 +290,7 @@ static struct virtio_config_ops lguest_config_ops = { .set = lg_set, .get_status = lg_get_status, .set_status = lg_set_status, + .reset = lg_reset, .find_vq = lg_find_vq, .del_vq = lg_del_vq, }; diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ec43284..6e0a9fe 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -390,13 +390,14 @@ static void virtnet_remove(struct virtio_device *vdev) struct virtnet_info *vi = vdev->priv; struct sk_buff *skb; + /* Stop all the virtqueues. */ + vdev->config->reset(vdev); + /* Free our skbs in send and recv queues, if any. */ - vi->rvq->vq_ops->shutdown(vi->rvq); while ((skb = __skb_dequeue(&vi->recv)) != NULL) { kfree_skb(skb); vi->num--; } - vi->svq->vq_ops->shutdown(vi->svq); while ((skb = __skb_dequeue(&vi->send)) != NULL) kfree_skb(skb); diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 303cb6f..7dddb18 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -102,9 +102,13 @@ static int virtio_dev_remove(struct device *_d) struct virtio_driver *drv = container_of(dev->dev.driver, struct virtio_driver, driver); - dev->config->set_status(dev, dev->config->get_status(dev) - & ~VIRTIO_CONFIG_S_DRIVER); drv->remove(dev); + + /* Driver should have reset device. */ + BUG_ON(dev->config->get_status(dev)); + + /* Acknowledge the device's existence again. */ + add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); return 0; } @@ -130,6 +134,10 @@ int register_virtio_device(struct virtio_device *dev) dev->dev.bus = &virtio_bus; sprintf(dev->dev.bus_id, "%u", dev->index); + /* We always start by resetting the device, in case a previous + * driver messed it up. This also tests that code path a little. */ + dev->config->reset(dev); + /* Acknowledge that we've seen the device. */ add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index dbe1d35..9849bab 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -173,16 +173,6 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head) vq->num_free++; } -/* FIXME: We need to tell other side about removal, to synchronize. */ -static void vring_shutdown(struct virtqueue *_vq) -{ - struct vring_virtqueue *vq = to_vvq(_vq); - unsigned int i; - - for (i = 0; i < vq->vring.num; i++) - detach_buf(vq, i); -} - static inline bool more_used(const struct vring_virtqueue *vq) { return vq->last_used_idx != vq->vring.used->idx; @@ -278,7 +268,6 @@ static struct virtqueue_ops vring_vq_ops = { .kick = vring_kick, .disable_cb = vring_disable_cb, .enable_cb = vring_enable_cb, - .shutdown = vring_shutdown, }; struct virtqueue *vring_new_virtqueue(unsigned int num, diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 78408d5..260d1fc 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -45,9 +45,6 @@ struct virtqueue * vq: the struct virtqueue we're talking about. * This returns "false" (and doesn't re-enable) if there are pending * buffers in the queue, to avoid a race. - * @shutdown: "unadd" all buffers. - * vq: the struct virtqueue we're talking about. - * Remove everything from the queue. * * Locking rules are straightforward: the driver is responsible for * locking. No two operations may be invoked simultaneously. @@ -67,8 +64,6 @@ struct virtqueue_ops { void (*disable_cb)(struct virtqueue *vq); bool (*enable_cb)(struct virtqueue *vq); - - void (*shutdown)(struct virtqueue *vq); }; /** diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 81f828a..d581b29 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -43,6 +43,9 @@ struct virtio_device; * @set_status: write the status byte * vdev: the virtio_device * status: the new status byte + * @reset: reset the device + * vdev: the virtio device + * After this, status and feature negotiation must be done again * @find_vq: find a virtqueue and instantiate it. * vdev: the virtio_device * index: the 0-based virtqueue number in case there's more than one. @@ -59,6 +62,7 @@ struct virtio_config_ops const void *buf, unsigned len); u8 (*get_status)(struct virtio_device *vdev); void (*set_status)(struct virtio_device *vdev, u8 status); + void (*reset)(struct virtio_device *vdev); struct virtqueue *(*find_vq)(struct virtio_device *vdev, unsigned index, void (*callback)(struct virtqueue *)); |