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-rw-r--r--drivers/virtio/virtio_balloon.c108
-rw-r--r--drivers/virtio/virtio_mmio.c4
-rw-r--r--drivers/virtio/virtio_pci.c110
-rw-r--r--drivers/virtio/virtio_ring.c249
4 files changed, 402 insertions, 69 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 94fd738a7741..95aeedf198f8 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -1,4 +1,5 @@
-/* Virtio balloon implementation, inspired by Dor Loar and Marcelo
+/*
+ * Virtio balloon implementation, inspired by Dor Laor and Marcelo
* Tosatti's implementations.
*
* Copyright 2008 Rusty Russell IBM Corporation
@@ -17,7 +18,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
-//#define DEBUG
+
#include <linux/virtio.h>
#include <linux/virtio_balloon.h>
#include <linux/swap.h>
@@ -87,7 +88,7 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
init_completion(&vb->acked);
/* We should always be able to add one buffer to an empty queue. */
- if (virtqueue_add_buf(vq, &sg, 1, 0, vb) < 0)
+ if (virtqueue_add_buf(vq, &sg, 1, 0, vb, GFP_KERNEL) < 0)
BUG();
virtqueue_kick(vq);
@@ -149,7 +150,6 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
vb->num_pages--;
}
-
/*
* Note that if
* virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST);
@@ -220,7 +220,7 @@ static void stats_handle_request(struct virtio_balloon *vb)
vq = vb->stats_vq;
sg_init_one(&sg, vb->stats, sizeof(vb->stats));
- if (virtqueue_add_buf(vq, &sg, 1, 0, vb) < 0)
+ if (virtqueue_add_buf(vq, &sg, 1, 0, vb, GFP_KERNEL) < 0)
BUG();
virtqueue_kick(vq);
}
@@ -275,32 +275,21 @@ static int balloon(void *_vballoon)
return 0;
}
-static int virtballoon_probe(struct virtio_device *vdev)
+static int init_vqs(struct virtio_balloon *vb)
{
- struct virtio_balloon *vb;
struct virtqueue *vqs[3];
vq_callback_t *callbacks[] = { balloon_ack, balloon_ack, stats_request };
const char *names[] = { "inflate", "deflate", "stats" };
int err, nvqs;
- vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);
- if (!vb) {
- err = -ENOMEM;
- goto out;
- }
-
- INIT_LIST_HEAD(&vb->pages);
- vb->num_pages = 0;
- init_waitqueue_head(&vb->config_change);
- vb->vdev = vdev;
- vb->need_stats_update = 0;
-
- /* We expect two virtqueues: inflate and deflate,
- * and optionally stat. */
+ /*
+ * We expect two virtqueues: inflate and deflate, and
+ * optionally stat.
+ */
nvqs = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2;
- err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
+ err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names);
if (err)
- goto out_free_vb;
+ return err;
vb->inflate_vq = vqs[0];
vb->deflate_vq = vqs[1];
@@ -313,10 +302,34 @@ static int virtballoon_probe(struct virtio_device *vdev)
* use it to signal us later.
*/
sg_init_one(&sg, vb->stats, sizeof vb->stats);
- if (virtqueue_add_buf(vb->stats_vq, &sg, 1, 0, vb) < 0)
+ if (virtqueue_add_buf(vb->stats_vq, &sg, 1, 0, vb, GFP_KERNEL)
+ < 0)
BUG();
virtqueue_kick(vb->stats_vq);
}
+ return 0;
+}
+
+static int virtballoon_probe(struct virtio_device *vdev)
+{
+ struct virtio_balloon *vb;
+ int err;
+
+ vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);
+ if (!vb) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ INIT_LIST_HEAD(&vb->pages);
+ vb->num_pages = 0;
+ init_waitqueue_head(&vb->config_change);
+ vb->vdev = vdev;
+ vb->need_stats_update = 0;
+
+ err = init_vqs(vb);
+ if (err)
+ goto out_free_vb;
vb->thread = kthread_run(balloon, vb, "vballoon");
if (IS_ERR(vb->thread)) {
@@ -351,6 +364,48 @@ static void __devexit virtballoon_remove(struct virtio_device *vdev)
kfree(vb);
}
+#ifdef CONFIG_PM
+static int virtballoon_freeze(struct virtio_device *vdev)
+{
+ /*
+ * The kthread is already frozen by the PM core before this
+ * function is called.
+ */
+
+ /* Ensure we don't get any more requests from the host */
+ vdev->config->reset(vdev);
+ vdev->config->del_vqs(vdev);
+ return 0;
+}
+
+static int virtballoon_thaw(struct virtio_device *vdev)
+{
+ return init_vqs(vdev->priv);
+}
+
+static int virtballoon_restore(struct virtio_device *vdev)
+{
+ struct virtio_balloon *vb = vdev->priv;
+ struct page *page, *page2;
+
+ /* We're starting from a clean slate */
+ vb->num_pages = 0;
+
+ /*
+ * If a request wasn't complete at the time of freezing, this
+ * could have been set.
+ */
+ vb->need_stats_update = 0;
+
+ /* We don't have these pages in the balloon anymore! */
+ list_for_each_entry_safe(page, page2, &vb->pages, lru) {
+ list_del(&page->lru);
+ totalram_pages++;
+ }
+ return init_vqs(vdev->priv);
+}
+#endif
+
static unsigned int features[] = {
VIRTIO_BALLOON_F_MUST_TELL_HOST,
VIRTIO_BALLOON_F_STATS_VQ,
@@ -365,6 +420,11 @@ static struct virtio_driver virtio_balloon_driver = {
.probe = virtballoon_probe,
.remove = __devexit_p(virtballoon_remove),
.config_changed = virtballoon_changed,
+#ifdef CONFIG_PM
+ .freeze = virtballoon_freeze,
+ .restore = virtballoon_restore,
+ .thaw = virtballoon_thaw,
+#endif
};
static int __init init(void)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 0269717436af..01d6dc250d5c 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -310,8 +310,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
/* Create the vring */
- vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN,
- vdev, info->queue, vm_notify, callback, name);
+ vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN, vdev,
+ true, info->queue, vm_notify, callback, name);
if (!vq) {
err = -ENOMEM;
goto error_new_virtqueue;
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index baabb7937ec2..635e1efb3792 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -55,6 +55,10 @@ struct virtio_pci_device
unsigned msix_vectors;
/* Vectors allocated, excluding per-vq vectors if any */
unsigned msix_used_vectors;
+
+ /* Status saved during hibernate/restore */
+ u8 saved_status;
+
/* Whether we have vector per vq */
bool per_vq_vectors;
};
@@ -414,8 +418,8 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
/* create the vring */
- vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
- vdev, info->queue, vp_notify, callback, name);
+ vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
+ true, info->queue, vp_notify, callback, name);
if (!vq) {
err = -ENOMEM;
goto out_activate_queue;
@@ -716,19 +720,114 @@ static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
}
#ifdef CONFIG_PM
-static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
+static int virtio_pci_suspend(struct device *dev)
{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+
pci_save_state(pci_dev);
pci_set_power_state(pci_dev, PCI_D3hot);
return 0;
}
-static int virtio_pci_resume(struct pci_dev *pci_dev)
+static int virtio_pci_resume(struct device *dev)
{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+
pci_restore_state(pci_dev);
pci_set_power_state(pci_dev, PCI_D0);
return 0;
}
+
+static int virtio_pci_freeze(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+ struct virtio_driver *drv;
+ int ret;
+
+ drv = container_of(vp_dev->vdev.dev.driver,
+ struct virtio_driver, driver);
+
+ ret = 0;
+ vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
+ if (drv && drv->freeze)
+ ret = drv->freeze(&vp_dev->vdev);
+
+ if (!ret)
+ pci_disable_device(pci_dev);
+ return ret;
+}
+
+static int restore_common(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+ int ret;
+
+ ret = pci_enable_device(pci_dev);
+ if (ret)
+ return ret;
+ pci_set_master(pci_dev);
+ vp_finalize_features(&vp_dev->vdev);
+
+ return ret;
+}
+
+static int virtio_pci_thaw(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+ struct virtio_driver *drv;
+ int ret;
+
+ ret = restore_common(dev);
+ if (ret)
+ return ret;
+
+ drv = container_of(vp_dev->vdev.dev.driver,
+ struct virtio_driver, driver);
+
+ if (drv && drv->thaw)
+ ret = drv->thaw(&vp_dev->vdev);
+ else if (drv && drv->restore)
+ ret = drv->restore(&vp_dev->vdev);
+
+ /* Finally, tell the device we're all set */
+ if (!ret)
+ vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
+
+ return ret;
+}
+
+static int virtio_pci_restore(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+ struct virtio_driver *drv;
+ int ret;
+
+ drv = container_of(vp_dev->vdev.dev.driver,
+ struct virtio_driver, driver);
+
+ ret = restore_common(dev);
+ if (!ret && drv && drv->restore)
+ ret = drv->restore(&vp_dev->vdev);
+
+ /* Finally, tell the device we're all set */
+ if (!ret)
+ vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
+
+ return ret;
+}
+
+static const struct dev_pm_ops virtio_pci_pm_ops = {
+ .suspend = virtio_pci_suspend,
+ .resume = virtio_pci_resume,
+ .freeze = virtio_pci_freeze,
+ .thaw = virtio_pci_thaw,
+ .restore = virtio_pci_restore,
+ .poweroff = virtio_pci_suspend,
+};
#endif
static struct pci_driver virtio_pci_driver = {
@@ -737,8 +836,7 @@ static struct pci_driver virtio_pci_driver = {
.probe = virtio_pci_probe,
.remove = __devexit_p(virtio_pci_remove),
#ifdef CONFIG_PM
- .suspend = virtio_pci_suspend,
- .resume = virtio_pci_resume,
+ .driver.pm = &virtio_pci_pm_ops,
#endif
};
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c7a2c208f6ea..5aa43c3392a2 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -22,23 +22,27 @@
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/hrtimer.h>
/* virtio guest is communicating with a virtual "device" that actually runs on
* a host processor. Memory barriers are used to control SMP effects. */
#ifdef CONFIG_SMP
/* Where possible, use SMP barriers which are more lightweight than mandatory
* barriers, because mandatory barriers control MMIO effects on accesses
- * through relaxed memory I/O windows (which virtio does not use). */
-#define virtio_mb() smp_mb()
-#define virtio_rmb() smp_rmb()
-#define virtio_wmb() smp_wmb()
+ * through relaxed memory I/O windows (which virtio-pci does not use). */
+#define virtio_mb(vq) \
+ do { if ((vq)->weak_barriers) smp_mb(); else mb(); } while(0)
+#define virtio_rmb(vq) \
+ do { if ((vq)->weak_barriers) smp_rmb(); else rmb(); } while(0)
+#define virtio_wmb(vq) \
+ do { if ((vq)->weak_barriers) smp_wmb(); else wmb(); } while(0)
#else
/* We must force memory ordering even if guest is UP since host could be
* running on another CPU, but SMP barriers are defined to barrier() in that
* configuration. So fall back to mandatory barriers instead. */
-#define virtio_mb() mb()
-#define virtio_rmb() rmb()
-#define virtio_wmb() wmb()
+#define virtio_mb(vq) mb()
+#define virtio_rmb(vq) rmb()
+#define virtio_wmb(vq) wmb()
#endif
#ifdef DEBUG
@@ -77,6 +81,9 @@ struct vring_virtqueue
/* Actual memory layout for this queue */
struct vring vring;
+ /* Can we use weak barriers? */
+ bool weak_barriers;
+
/* Other side has made a mess, don't try any more. */
bool broken;
@@ -102,6 +109,10 @@ struct vring_virtqueue
#ifdef DEBUG
/* They're supposed to lock for us. */
unsigned int in_use;
+
+ /* Figure out if their kicks are too delayed. */
+ bool last_add_time_valid;
+ ktime_t last_add_time;
#endif
/* Tokens for callbacks. */
@@ -160,12 +171,29 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
return head;
}
-int virtqueue_add_buf_gfp(struct virtqueue *_vq,
- struct scatterlist sg[],
- unsigned int out,
- unsigned int in,
- void *data,
- gfp_t gfp)
+/**
+ * virtqueue_add_buf - expose buffer to other end
+ * @vq: the struct virtqueue we're talking about.
+ * @sg: the description of the buffer(s).
+ * @out_num: the number of sg readable by other side
+ * @in_num: the number of sg which are writable (after readable ones)
+ * @data: the token identifying the buffer.
+ * @gfp: how to do memory allocations (if necessary).
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns remaining capacity of queue or a negative error
+ * (ie. ENOSPC). Note that it only really makes sense to treat all
+ * positive return values as "available": indirect buffers mean that
+ * we can put an entire sg[] array inside a single queue entry.
+ */
+int virtqueue_add_buf(struct virtqueue *_vq,
+ struct scatterlist sg[],
+ unsigned int out,
+ unsigned int in,
+ void *data,
+ gfp_t gfp)
{
struct vring_virtqueue *vq = to_vvq(_vq);
unsigned int i, avail, uninitialized_var(prev);
@@ -175,6 +203,19 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq,
BUG_ON(data == NULL);
+#ifdef DEBUG
+ {
+ ktime_t now = ktime_get();
+
+ /* No kick or get, with .1 second between? Warn. */
+ if (vq->last_add_time_valid)
+ WARN_ON(ktime_to_ms(ktime_sub(now, vq->last_add_time))
+ > 100);
+ vq->last_add_time = now;
+ vq->last_add_time_valid = true;
+ }
+#endif
+
/* If the host supports indirect descriptor tables, and we have multiple
* buffers, then go indirect. FIXME: tune this threshold */
if (vq->indirect && (out + in) > 1 && vq->num_free) {
@@ -227,40 +268,102 @@ add_head:
vq->data[head] = data;
/* Put entry in available array (but don't update avail->idx until they
- * do sync). FIXME: avoid modulus here? */
- avail = (vq->vring.avail->idx + vq->num_added++) % vq->vring.num;
+ * do sync). */
+ avail = (vq->vring.avail->idx & (vq->vring.num-1));
vq->vring.avail->ring[avail] = head;
+ /* Descriptors and available array need to be set before we expose the
+ * new available array entries. */
+ virtio_wmb(vq);
+ vq->vring.avail->idx++;
+ vq->num_added++;
+
+ /* This is very unlikely, but theoretically possible. Kick
+ * just in case. */
+ if (unlikely(vq->num_added == (1 << 16) - 1))
+ virtqueue_kick(_vq);
+
pr_debug("Added buffer head %i to %p\n", head, vq);
END_USE(vq);
return vq->num_free;
}
-EXPORT_SYMBOL_GPL(virtqueue_add_buf_gfp);
+EXPORT_SYMBOL_GPL(virtqueue_add_buf);
-void virtqueue_kick(struct virtqueue *_vq)
+/**
+ * virtqueue_kick_prepare - first half of split virtqueue_kick call.
+ * @vq: the struct virtqueue
+ *
+ * Instead of virtqueue_kick(), you can do:
+ * if (virtqueue_kick_prepare(vq))
+ * virtqueue_notify(vq);
+ *
+ * This is sometimes useful because the virtqueue_kick_prepare() needs
+ * to be serialized, but the actual virtqueue_notify() call does not.
+ */
+bool virtqueue_kick_prepare(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
u16 new, old;
+ bool needs_kick;
+
START_USE(vq);
- /* Descriptors and available array need to be set before we expose the
- * new available array entries. */
- virtio_wmb();
+ /* We need to expose available array entries before checking avail
+ * event. */
+ virtio_mb(vq);
- old = vq->vring.avail->idx;
- new = vq->vring.avail->idx = old + vq->num_added;
+ old = vq->vring.avail->idx - vq->num_added;
+ new = vq->vring.avail->idx;
vq->num_added = 0;
- /* Need to update avail index before checking if we should notify */
- virtio_mb();
-
- if (vq->event ?
- vring_need_event(vring_avail_event(&vq->vring), new, old) :
- !(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY))
- /* Prod other side to tell it about changes. */
- vq->notify(&vq->vq);
+#ifdef DEBUG
+ if (vq->last_add_time_valid) {
+ WARN_ON(ktime_to_ms(ktime_sub(ktime_get(),
+ vq->last_add_time)) > 100);
+ }
+ vq->last_add_time_valid = false;
+#endif
+ if (vq->event) {
+ needs_kick = vring_need_event(vring_avail_event(&vq->vring),
+ new, old);
+ } else {
+ needs_kick = !(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY);
+ }
END_USE(vq);
+ return needs_kick;
+}
+EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
+
+/**
+ * virtqueue_notify - second half of split virtqueue_kick call.
+ * @vq: the struct virtqueue
+ *
+ * This does not need to be serialized.
+ */
+void virtqueue_notify(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ /* Prod other side to tell it about changes. */
+ vq->notify(_vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_notify);
+
+/**
+ * virtqueue_kick - update after add_buf
+ * @vq: the struct virtqueue
+ *
+ * After one or more virtqueue_add_buf calls, invoke this to kick
+ * the other side.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ */
+void virtqueue_kick(struct virtqueue *vq)
+{
+ if (virtqueue_kick_prepare(vq))
+ virtqueue_notify(vq);
}
EXPORT_SYMBOL_GPL(virtqueue_kick);
@@ -294,11 +397,28 @@ static inline bool more_used(const struct vring_virtqueue *vq)
return vq->last_used_idx != vq->vring.used->idx;
}
+/**
+ * virtqueue_get_buf - get the next used buffer
+ * @vq: the struct virtqueue we're talking about.
+ * @len: the length written into the buffer
+ *
+ * If the driver wrote data into the buffer, @len will be set to the
+ * amount written. This means you don't need to clear the buffer
+ * beforehand to ensure there's no data leakage in the case of short
+ * writes.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ *
+ * Returns NULL if there are no used buffers, or the "data" token
+ * handed to virtqueue_add_buf().
+ */
void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
{
struct vring_virtqueue *vq = to_vvq(_vq);
void *ret;
unsigned int i;
+ u16 last_used;
START_USE(vq);
@@ -314,10 +434,11 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
}
/* Only get used array entries after they have been exposed by host. */
- virtio_rmb();
+ virtio_rmb(vq);
- i = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].id;
- *len = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].len;
+ last_used = (vq->last_used_idx & (vq->vring.num - 1));
+ i = vq->vring.used->ring[last_used].id;
+ *len = vq->vring.used->ring[last_used].len;
if (unlikely(i >= vq->vring.num)) {
BAD_RING(vq, "id %u out of range\n", i);
@@ -337,14 +458,27 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
* the read in the next get_buf call. */
if (!(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
vring_used_event(&vq->vring) = vq->last_used_idx;
- virtio_mb();
+ virtio_mb(vq);
}
+#ifdef DEBUG
+ vq->last_add_time_valid = false;
+#endif
+
END_USE(vq);
return ret;
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf);
+/**
+ * virtqueue_disable_cb - disable callbacks
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * Note that this is not necessarily synchronous, hence unreliable and only
+ * useful as an optimization.
+ *
+ * Unlike other operations, this need not be serialized.
+ */
void virtqueue_disable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -353,6 +487,17 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
}
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
+/**
+ * virtqueue_enable_cb - restart callbacks after disable_cb.
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * This re-enables callbacks; it returns "false" if there are pending
+ * buffers in the queue, to detect a possible race between the driver
+ * checking for more work, and enabling callbacks.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ */
bool virtqueue_enable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -366,7 +511,7 @@ bool virtqueue_enable_cb(struct virtqueue *_vq)
* entry. Always do both to keep code simple. */
vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
vring_used_event(&vq->vring) = vq->last_used_idx;
- virtio_mb();
+ virtio_mb(vq);
if (unlikely(more_used(vq))) {
END_USE(vq);
return false;
@@ -377,6 +522,19 @@ bool virtqueue_enable_cb(struct virtqueue *_vq)
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
+/**
+ * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * This re-enables callbacks but hints to the other side to delay
+ * interrupts until most of the available buffers have been processed;
+ * it returns "false" if there are many pending buffers in the queue,
+ * to detect a possible race between the driver checking for more work,
+ * and enabling callbacks.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ */
bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -393,7 +551,7 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
/* TODO: tune this threshold */
bufs = (u16)(vq->vring.avail->idx - vq->last_used_idx) * 3 / 4;
vring_used_event(&vq->vring) = vq->last_used_idx + bufs;
- virtio_mb();
+ virtio_mb(vq);
if (unlikely((u16)(vq->vring.used->idx - vq->last_used_idx) > bufs)) {
END_USE(vq);
return false;
@@ -404,6 +562,14 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
+/**
+ * virtqueue_detach_unused_buf - detach first unused buffer
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * Returns NULL or the "data" token handed to virtqueue_add_buf().
+ * This is not valid on an active queue; it is useful only for device
+ * shutdown.
+ */
void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -453,6 +619,7 @@ EXPORT_SYMBOL_GPL(vring_interrupt);
struct virtqueue *vring_new_virtqueue(unsigned int num,
unsigned int vring_align,
struct virtio_device *vdev,
+ bool weak_barriers,
void *pages,
void (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
@@ -476,12 +643,14 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
vq->vq.vdev = vdev;
vq->vq.name = name;
vq->notify = notify;
+ vq->weak_barriers = weak_barriers;
vq->broken = false;
vq->last_used_idx = 0;
vq->num_added = 0;
list_add_tail(&vq->vq.list, &vdev->vqs);
#ifdef DEBUG
vq->in_use = false;
+ vq->last_add_time_valid = false;
#endif
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC);
@@ -530,7 +699,13 @@ void vring_transport_features(struct virtio_device *vdev)
}
EXPORT_SYMBOL_GPL(vring_transport_features);
-/* return the size of the vring within the virtqueue */
+/**
+ * virtqueue_get_vring_size - return the size of the virtqueue's vring
+ * @vq: the struct virtqueue containing the vring of interest.
+ *
+ * Returns the size of the vring. This is mainly used for boasting to
+ * userspace. Unlike other operations, this need not be serialized.
+ */
unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
{
generated by cgit v1.2.3 (git 2.0.4) at 2024-09-16 10:51:12 +0000