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authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-12 06:10:33 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-12 06:10:33 +0200
commit5c02c392cd2320e8d612376d6b72b6548a680923 (patch)
tree56615b31e21b34414821564cd9bf4c13d7e5d14e
parentMerge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost (diff)
parentvirtio_scsi: don't call virtqueue_add_sgs(... GFP_NOIO) holding spinlock. (diff)
downloadlinux-5c02c392cd2320e8d612376d6b72b6548a680923.tar.xz
linux-5c02c392cd2320e8d612376d6b72b6548a680923.zip
Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio updates from Rusty Russell: "Main excitement is a virtio_scsi fix for alloc holding spinlock on the abort path, which I refuse to CC stable since (1) I discovered it myself, and (2) it's been there forever with no reports" * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: virtio_scsi: don't call virtqueue_add_sgs(... GFP_NOIO) holding spinlock. virtio-rng: fixes for device registration/unregistration virtio-rng: fix boot with virtio-rng device virtio-rng: support multiple virtio-rng devices virtio_ccw: introduce device_lost in virtio_ccw_device virtio: virtio_break_device() to mark all virtqueues broken.
-rw-r--r--drivers/char/hw_random/virtio-rng.c105
-rw-r--r--drivers/s390/kvm/virtio_ccw.c49
-rw-r--r--drivers/scsi/virtio_scsi.c15
-rw-r--r--drivers/virtio/virtio_ring.c15
-rw-r--r--include/linux/virtio.h2
5 files changed, 127 insertions, 59 deletions
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 2ce0e225e58c..f3e71501de54 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -25,88 +25,115 @@
#include <linux/virtio_rng.h>
#include <linux/module.h>
-static struct virtqueue *vq;
-static unsigned int data_avail;
-static DECLARE_COMPLETION(have_data);
-static bool busy;
+static DEFINE_IDA(rng_index_ida);
+
+struct virtrng_info {
+ struct virtio_device *vdev;
+ struct hwrng hwrng;
+ struct virtqueue *vq;
+ unsigned int data_avail;
+ struct completion have_data;
+ bool busy;
+ char name[25];
+ int index;
+};
static void random_recv_done(struct virtqueue *vq)
{
+ struct virtrng_info *vi = vq->vdev->priv;
+
/* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
- if (!virtqueue_get_buf(vq, &data_avail))
+ if (!virtqueue_get_buf(vi->vq, &vi->data_avail))
return;
- complete(&have_data);
+ complete(&vi->have_data);
}
/* The host will fill any buffer we give it with sweet, sweet randomness. */
-static void register_buffer(u8 *buf, size_t size)
+static void register_buffer(struct virtrng_info *vi, u8 *buf, size_t size)
{
struct scatterlist sg;
sg_init_one(&sg, buf, size);
/* There should always be room for one buffer. */
- virtqueue_add_inbuf(vq, &sg, 1, buf, GFP_KERNEL);
+ virtqueue_add_inbuf(vi->vq, &sg, 1, buf, GFP_KERNEL);
- virtqueue_kick(vq);
+ virtqueue_kick(vi->vq);
}
static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
{
int ret;
+ struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
- if (!busy) {
- busy = true;
- init_completion(&have_data);
- register_buffer(buf, size);
+ if (!vi->busy) {
+ vi->busy = true;
+ init_completion(&vi->have_data);
+ register_buffer(vi, buf, size);
}
if (!wait)
return 0;
- ret = wait_for_completion_killable(&have_data);
+ ret = wait_for_completion_killable(&vi->have_data);
if (ret < 0)
return ret;
- busy = false;
+ vi->busy = false;
- return data_avail;
+ return vi->data_avail;
}
static void virtio_cleanup(struct hwrng *rng)
{
- if (busy)
- wait_for_completion(&have_data);
-}
+ struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
-
-static struct hwrng virtio_hwrng = {
- .name = "virtio",
- .cleanup = virtio_cleanup,
- .read = virtio_read,
-};
+ if (vi->busy)
+ wait_for_completion(&vi->have_data);
+}
static int probe_common(struct virtio_device *vdev)
{
- int err;
+ int err, index;
+ struct virtrng_info *vi = NULL;
+
+ vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);
+ if (!vi)
+ return -ENOMEM;
- if (vq) {
- /* We only support one device for now */
- return -EBUSY;
+ vi->index = index = ida_simple_get(&rng_index_ida, 0, 0, GFP_KERNEL);
+ if (index < 0) {
+ kfree(vi);
+ return index;
}
+ sprintf(vi->name, "virtio_rng.%d", index);
+ init_completion(&vi->have_data);
+
+ vi->hwrng = (struct hwrng) {
+ .read = virtio_read,
+ .cleanup = virtio_cleanup,
+ .priv = (unsigned long)vi,
+ .name = vi->name,
+ };
+ vdev->priv = vi;
+
/* We expect a single virtqueue. */
- vq = virtio_find_single_vq(vdev, random_recv_done, "input");
- if (IS_ERR(vq)) {
- err = PTR_ERR(vq);
- vq = NULL;
+ vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");
+ if (IS_ERR(vi->vq)) {
+ err = PTR_ERR(vi->vq);
+ vi->vq = NULL;
+ kfree(vi);
+ ida_simple_remove(&rng_index_ida, index);
return err;
}
- err = hwrng_register(&virtio_hwrng);
+ err = hwrng_register(&vi->hwrng);
if (err) {
vdev->config->del_vqs(vdev);
- vq = NULL;
+ vi->vq = NULL;
+ kfree(vi);
+ ida_simple_remove(&rng_index_ida, index);
return err;
}
@@ -115,11 +142,13 @@ static int probe_common(struct virtio_device *vdev)
static void remove_common(struct virtio_device *vdev)
{
+ struct virtrng_info *vi = vdev->priv;
vdev->config->reset(vdev);
- busy = false;
- hwrng_unregister(&virtio_hwrng);
+ vi->busy = false;
+ hwrng_unregister(&vi->hwrng);
vdev->config->del_vqs(vdev);
- vq = NULL;
+ ida_simple_remove(&rng_index_ida, vi->index);
+ kfree(vi);
}
static int virtrng_probe(struct virtio_device *vdev)
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 1e1fc671f89a..d2c0b442bce5 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/io.h>
#include <linux/kvm_para.h>
+#include <linux/notifier.h>
#include <asm/setup.h>
#include <asm/irq.h>
#include <asm/cio.h>
@@ -62,6 +63,7 @@ struct virtio_ccw_device {
struct vq_config_block *config_block;
bool is_thinint;
bool going_away;
+ bool device_lost;
void *airq_info;
};
@@ -1010,11 +1012,14 @@ static void virtio_ccw_remove(struct ccw_device *cdev)
unsigned long flags;
struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
- if (vcdev && cdev->online)
+ if (vcdev && cdev->online) {
+ if (vcdev->device_lost)
+ virtio_break_device(&vcdev->vdev);
unregister_virtio_device(&vcdev->vdev);
- spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
- dev_set_drvdata(&cdev->dev, NULL);
- spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+ spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+ dev_set_drvdata(&cdev->dev, NULL);
+ spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+ }
cdev->handler = NULL;
}
@@ -1023,12 +1028,14 @@ static int virtio_ccw_offline(struct ccw_device *cdev)
unsigned long flags;
struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
- if (vcdev) {
- unregister_virtio_device(&vcdev->vdev);
- spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
- dev_set_drvdata(&cdev->dev, NULL);
- spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
- }
+ if (!vcdev)
+ return 0;
+ if (vcdev->device_lost)
+ virtio_break_device(&vcdev->vdev);
+ unregister_virtio_device(&vcdev->vdev);
+ spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+ dev_set_drvdata(&cdev->dev, NULL);
+ spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
return 0;
}
@@ -1096,8 +1103,26 @@ out_free:
static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
{
- /* TODO: Check whether we need special handling here. */
- return 0;
+ int rc;
+ struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+
+ /*
+ * Make sure vcdev is set
+ * i.e. set_offline/remove callback not already running
+ */
+ if (!vcdev)
+ return NOTIFY_DONE;
+
+ switch (event) {
+ case CIO_GONE:
+ vcdev->device_lost = true;
+ rc = NOTIFY_DONE;
+ break;
+ default:
+ rc = NOTIFY_DONE;
+ break;
+ }
+ return rc;
}
static struct ccw_device_id virtio_ids[] = {
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index d4727b339474..99fdb9403944 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -393,11 +393,10 @@ static void virtscsi_event_done(struct virtqueue *vq)
* @cmd : command structure
* @req_size : size of the request buffer
* @resp_size : size of the response buffer
- * @gfp : flags to use for memory allocations
*/
static int virtscsi_add_cmd(struct virtqueue *vq,
struct virtio_scsi_cmd *cmd,
- size_t req_size, size_t resp_size, gfp_t gfp)
+ size_t req_size, size_t resp_size)
{
struct scsi_cmnd *sc = cmd->sc;
struct scatterlist *sgs[4], req, resp;
@@ -429,19 +428,19 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
if (in)
sgs[out_num + in_num++] = in->sgl;
- return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
+ return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
}
static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
struct virtio_scsi_cmd *cmd,
- size_t req_size, size_t resp_size, gfp_t gfp)
+ size_t req_size, size_t resp_size)
{
unsigned long flags;
int err;
bool needs_kick = false;
spin_lock_irqsave(&vq->vq_lock, flags);
- err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp);
+ err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
if (!err)
needs_kick = virtqueue_kick_prepare(vq->vq);
@@ -484,8 +483,7 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
if (virtscsi_kick_cmd(req_vq, cmd,
- sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
- GFP_ATOMIC) != 0)
+ sizeof cmd->req.cmd, sizeof cmd->resp.cmd) != 0)
return SCSI_MLQUEUE_HOST_BUSY;
return 0;
}
@@ -542,8 +540,7 @@ static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
cmd->comp = &comp;
if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
- sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
- GFP_NOIO) < 0)
+ sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
goto out;
wait_for_completion(&comp);
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1e443629f76d..4d08f45a9c29 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -865,4 +865,19 @@ bool virtqueue_is_broken(struct virtqueue *_vq)
}
EXPORT_SYMBOL_GPL(virtqueue_is_broken);
+/*
+ * This should prevent the device from being used, allowing drivers to
+ * recover. You may need to grab appropriate locks to flush.
+ */
+void virtio_break_device(struct virtio_device *dev)
+{
+ struct virtqueue *_vq;
+
+ list_for_each_entry(_vq, &dev->vqs, list) {
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ vq->broken = true;
+ }
+}
+EXPORT_SYMBOL_GPL(virtio_break_device);
+
MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index e4abb84199be..b46671e28de2 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -106,6 +106,8 @@ static inline struct virtio_device *dev_to_virtio(struct device *_dev)
int register_virtio_device(struct virtio_device *dev);
void unregister_virtio_device(struct virtio_device *dev);
+void virtio_break_device(struct virtio_device *dev);
+
/**
* virtio_driver - operations for a virtio I/O driver
* @driver: underlying device driver (populate name and owner).