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-rw-r--r--drivers/virtio/virtio.c29
-rw-r--r--drivers/virtio/virtio_balloon.c27
-rw-r--r--drivers/virtio/virtio_pci.c307
-rw-r--r--drivers/virtio/virtio_ring.c102
4 files changed, 396 insertions, 69 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 018c070..3a43ebf 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -31,21 +31,37 @@ static ssize_t modalias_show(struct device *_d,
return sprintf(buf, "virtio:d%08Xv%08X\n",
dev->id.device, dev->id.vendor);
}
+static ssize_t features_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
+ unsigned int i;
+ ssize_t len = 0;
+
+ /* We actually represent this as a bitstring, as it could be
+ * arbitrary length in future. */
+ for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
+ len += sprintf(buf+len, "%c",
+ test_bit(i, dev->features) ? '1' : '0');
+ len += sprintf(buf+len, "\n");
+ return len;
+}
static struct device_attribute virtio_dev_attrs[] = {
__ATTR_RO(device),
__ATTR_RO(vendor),
__ATTR_RO(status),
__ATTR_RO(modalias),
+ __ATTR_RO(features),
__ATTR_NULL
};
static inline int virtio_id_match(const struct virtio_device *dev,
const struct virtio_device_id *id)
{
- if (id->device != dev->id.device)
+ if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
return 0;
- return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
+ return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
}
/* This looks through all the IDs a driver claims to support. If any of them
@@ -118,13 +134,14 @@ static int virtio_dev_probe(struct device *_d)
if (device_features & (1 << i))
set_bit(i, dev->features);
+ dev->config->finalize_features(dev);
+
err = drv->probe(dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
- else {
- dev->config->finalize_features(dev);
+ else
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
- }
+
return err;
}
@@ -185,6 +202,8 @@ int register_virtio_device(struct virtio_device *dev)
/* Acknowledge that we've seen the device. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+ INIT_LIST_HEAD(&dev->vqs);
+
/* device_register() causes the bus infrastructure to look for a
* matching driver. */
err = device_register(&dev->dev);
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 9c76a06..26b2782 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -204,6 +204,9 @@ static int balloon(void *_vballoon)
static int virtballoon_probe(struct virtio_device *vdev)
{
struct virtio_balloon *vb;
+ struct virtqueue *vqs[2];
+ vq_callback_t *callbacks[] = { balloon_ack, balloon_ack };
+ const char *names[] = { "inflate", "deflate" };
int err;
vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);
@@ -218,22 +221,17 @@ static int virtballoon_probe(struct virtio_device *vdev)
vb->vdev = vdev;
/* We expect two virtqueues. */
- vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack);
- if (IS_ERR(vb->inflate_vq)) {
- err = PTR_ERR(vb->inflate_vq);
+ err = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names);
+ if (err)
goto out_free_vb;
- }
- vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack);
- if (IS_ERR(vb->deflate_vq)) {
- err = PTR_ERR(vb->deflate_vq);
- goto out_del_inflate_vq;
- }
+ vb->inflate_vq = vqs[0];
+ vb->deflate_vq = vqs[1];
vb->thread = kthread_run(balloon, vb, "vballoon");
if (IS_ERR(vb->thread)) {
err = PTR_ERR(vb->thread);
- goto out_del_deflate_vq;
+ goto out_del_vqs;
}
vb->tell_host_first
@@ -241,10 +239,8 @@ static int virtballoon_probe(struct virtio_device *vdev)
return 0;
-out_del_deflate_vq:
- vdev->config->del_vq(vb->deflate_vq);
-out_del_inflate_vq:
- vdev->config->del_vq(vb->inflate_vq);
+out_del_vqs:
+ vdev->config->del_vqs(vdev);
out_free_vb:
kfree(vb);
out:
@@ -264,8 +260,7 @@ static void virtballoon_remove(struct virtio_device *vdev)
/* Now we reset the device so we can clean up the queues. */
vdev->config->reset(vdev);
- vdev->config->del_vq(vb->deflate_vq);
- vdev->config->del_vq(vb->inflate_vq);
+ vdev->config->del_vqs(vdev);
kfree(vb);
}
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 330aacb..193c8f0 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -42,6 +42,26 @@ struct virtio_pci_device
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
+
+ /* MSI-X support */
+ int msix_enabled;
+ int intx_enabled;
+ struct msix_entry *msix_entries;
+ /* Name strings for interrupts. This size should be enough,
+ * and I'm too lazy to allocate each name separately. */
+ char (*msix_names)[256];
+ /* Number of available vectors */
+ unsigned msix_vectors;
+ /* Vectors allocated */
+ unsigned msix_used_vectors;
+};
+
+/* Constants for MSI-X */
+/* Use first vector for configuration changes, second and the rest for
+ * virtqueues Thus, we need at least 2 vectors for MSI. */
+enum {
+ VP_MSIX_CONFIG_VECTOR = 0,
+ VP_MSIX_VQ_VECTOR = 1,
};
struct virtio_pci_vq_info
@@ -60,6 +80,9 @@ struct virtio_pci_vq_info
/* the list node for the virtqueues list */
struct list_head node;
+
+ /* MSI-X vector (or none) */
+ unsigned vector;
};
/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
@@ -109,7 +132,8 @@ static void vp_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
+ void __iomem *ioaddr = vp_dev->ioaddr +
+ VIRTIO_PCI_CONFIG(vp_dev) + offset;
u8 *ptr = buf;
int i;
@@ -123,7 +147,8 @@ static void vp_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
+ void __iomem *ioaddr = vp_dev->ioaddr +
+ VIRTIO_PCI_CONFIG(vp_dev) + offset;
const u8 *ptr = buf;
int i;
@@ -164,6 +189,37 @@ static void vp_notify(struct virtqueue *vq)
iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
}
+/* Handle a configuration change: Tell driver if it wants to know. */
+static irqreturn_t vp_config_changed(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ struct virtio_driver *drv;
+ drv = container_of(vp_dev->vdev.dev.driver,
+ struct virtio_driver, driver);
+
+ if (drv && drv->config_changed)
+ drv->config_changed(&vp_dev->vdev);
+ return IRQ_HANDLED;
+}
+
+/* Notify all virtqueues on an interrupt. */
+static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ struct virtio_pci_vq_info *info;
+ irqreturn_t ret = IRQ_NONE;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_for_each_entry(info, &vp_dev->virtqueues, node) {
+ if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
+ ret = IRQ_HANDLED;
+ }
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+ return ret;
+}
+
/* A small wrapper to also acknowledge the interrupt when it's handled.
* I really need an EIO hook for the vring so I can ack the interrupt once we
* know that we'll be handling the IRQ but before we invoke the callback since
@@ -173,9 +229,6 @@ static void vp_notify(struct virtqueue *vq)
static irqreturn_t vp_interrupt(int irq, void *opaque)
{
struct virtio_pci_device *vp_dev = opaque;
- struct virtio_pci_vq_info *info;
- irqreturn_t ret = IRQ_NONE;
- unsigned long flags;
u8 isr;
/* reading the ISR has the effect of also clearing it so it's very
@@ -187,34 +240,137 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
return IRQ_NONE;
/* Configuration change? Tell driver if it wants to know. */
- if (isr & VIRTIO_PCI_ISR_CONFIG) {
- struct virtio_driver *drv;
- drv = container_of(vp_dev->vdev.dev.driver,
- struct virtio_driver, driver);
+ if (isr & VIRTIO_PCI_ISR_CONFIG)
+ vp_config_changed(irq, opaque);
- if (drv && drv->config_changed)
- drv->config_changed(&vp_dev->vdev);
+ return vp_vring_interrupt(irq, opaque);
+}
+
+static void vp_free_vectors(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ int i;
+
+ if (vp_dev->intx_enabled) {
+ free_irq(vp_dev->pci_dev->irq, vp_dev);
+ vp_dev->intx_enabled = 0;
}
- spin_lock_irqsave(&vp_dev->lock, flags);
- list_for_each_entry(info, &vp_dev->virtqueues, node) {
- if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
- ret = IRQ_HANDLED;
+ for (i = 0; i < vp_dev->msix_used_vectors; ++i)
+ free_irq(vp_dev->msix_entries[i].vector, vp_dev);
+ vp_dev->msix_used_vectors = 0;
+
+ if (vp_dev->msix_enabled) {
+ /* Disable the vector used for configuration */
+ iowrite16(VIRTIO_MSI_NO_VECTOR,
+ vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+ /* Flush the write out to device */
+ ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+
+ vp_dev->msix_enabled = 0;
+ pci_disable_msix(vp_dev->pci_dev);
}
- spin_unlock_irqrestore(&vp_dev->lock, flags);
+}
- return ret;
+static int vp_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
+ int *options, int noptions)
+{
+ int i;
+ for (i = 0; i < noptions; ++i)
+ if (!pci_enable_msix(dev, entries, options[i]))
+ return options[i];
+ return -EBUSY;
+}
+
+static int vp_request_vectors(struct virtio_device *vdev, unsigned max_vqs)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ const char *name = dev_name(&vp_dev->vdev.dev);
+ unsigned i, v;
+ int err = -ENOMEM;
+ /* We want at most one vector per queue and one for config changes.
+ * Fallback to separate vectors for config and a shared for queues.
+ * Finally fall back to regular interrupts. */
+ int options[] = { max_vqs + 1, 2 };
+ int nvectors = max(options[0], options[1]);
+
+ vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
+ GFP_KERNEL);
+ if (!vp_dev->msix_entries)
+ goto error_entries;
+ vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
+ GFP_KERNEL);
+ if (!vp_dev->msix_names)
+ goto error_names;
+
+ for (i = 0; i < nvectors; ++i)
+ vp_dev->msix_entries[i].entry = i;
+
+ err = vp_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries,
+ options, ARRAY_SIZE(options));
+ if (err < 0) {
+ /* Can't allocate enough MSI-X vectors, use regular interrupt */
+ vp_dev->msix_vectors = 0;
+ err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
+ IRQF_SHARED, name, vp_dev);
+ if (err)
+ goto error_irq;
+ vp_dev->intx_enabled = 1;
+ } else {
+ vp_dev->msix_vectors = err;
+ vp_dev->msix_enabled = 1;
+
+ /* Set the vector used for configuration */
+ v = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+ "%s-config", name);
+ err = request_irq(vp_dev->msix_entries[v].vector,
+ vp_config_changed, 0, vp_dev->msix_names[v],
+ vp_dev);
+ if (err)
+ goto error_irq;
+ ++vp_dev->msix_used_vectors;
+
+ iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+ /* Verify we had enough resources to assign the vector */
+ v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+ if (v == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto error_irq;
+ }
+ }
+
+ if (vp_dev->msix_vectors && vp_dev->msix_vectors != max_vqs + 1) {
+ /* Shared vector for all VQs */
+ v = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+ "%s-virtqueues", name);
+ err = request_irq(vp_dev->msix_entries[v].vector,
+ vp_vring_interrupt, 0, vp_dev->msix_names[v],
+ vp_dev);
+ if (err)
+ goto error_irq;
+ ++vp_dev->msix_used_vectors;
+ }
+ return 0;
+error_irq:
+ vp_free_vectors(vdev);
+ kfree(vp_dev->msix_names);
+error_names:
+ kfree(vp_dev->msix_entries);
+error_entries:
+ return err;
}
-/* the config->find_vq() implementation */
static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
- void (*callback)(struct virtqueue *vq))
+ void (*callback)(struct virtqueue *vq),
+ const char *name)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_vq_info *info;
struct virtqueue *vq;
unsigned long flags, size;
- u16 num;
+ u16 num, vector;
int err;
/* Select the queue we're interested in */
@@ -233,6 +389,7 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
info->queue_index = index;
info->num = num;
+ info->vector = VIRTIO_MSI_NO_VECTOR;
size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
@@ -247,7 +404,7 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
/* create the vring */
vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
- vdev, info->queue, vp_notify, callback);
+ vdev, info->queue, vp_notify, callback, name);
if (!vq) {
err = -ENOMEM;
goto out_activate_queue;
@@ -256,12 +413,43 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
vq->priv = info;
info->vq = vq;
+ /* allocate per-vq vector if available and necessary */
+ if (callback && vp_dev->msix_used_vectors < vp_dev->msix_vectors) {
+ vector = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[vector], sizeof *vp_dev->msix_names,
+ "%s-%s", dev_name(&vp_dev->vdev.dev), name);
+ err = request_irq(vp_dev->msix_entries[vector].vector,
+ vring_interrupt, 0,
+ vp_dev->msix_names[vector], vq);
+ if (err)
+ goto out_request_irq;
+ info->vector = vector;
+ ++vp_dev->msix_used_vectors;
+ } else
+ vector = VP_MSIX_VQ_VECTOR;
+
+ if (callback && vp_dev->msix_enabled) {
+ iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+ vector = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+ if (vector == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto out_assign;
+ }
+ }
+
spin_lock_irqsave(&vp_dev->lock, flags);
list_add(&info->node, &vp_dev->virtqueues);
spin_unlock_irqrestore(&vp_dev->lock, flags);
return vq;
+out_assign:
+ if (info->vector != VIRTIO_MSI_NO_VECTOR) {
+ free_irq(vp_dev->msix_entries[info->vector].vector, vq);
+ --vp_dev->msix_used_vectors;
+ }
+out_request_irq:
+ vring_del_virtqueue(vq);
out_activate_queue:
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
free_pages_exact(info->queue, size);
@@ -270,21 +458,27 @@ out_info:
return ERR_PTR(err);
}
-/* the config->del_vq() implementation */
static void vp_del_vq(struct virtqueue *vq)
{
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
struct virtio_pci_vq_info *info = vq->priv;
- unsigned long flags, size;
+ unsigned long size;
- spin_lock_irqsave(&vp_dev->lock, flags);
- list_del(&info->node);
- spin_unlock_irqrestore(&vp_dev->lock, flags);
+ iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+
+ if (info->vector != VIRTIO_MSI_NO_VECTOR)
+ free_irq(vp_dev->msix_entries[info->vector].vector, vq);
+
+ if (vp_dev->msix_enabled) {
+ iowrite16(VIRTIO_MSI_NO_VECTOR,
+ vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+ /* Flush the write out to device */
+ ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
+ }
vring_del_virtqueue(vq);
/* Select and deactivate the queue */
- iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
@@ -292,14 +486,57 @@ static void vp_del_vq(struct virtqueue *vq)
kfree(info);
}
+/* the config->del_vqs() implementation */
+static void vp_del_vqs(struct virtio_device *vdev)
+{
+ struct virtqueue *vq, *n;
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ vp_del_vq(vq);
+
+ vp_free_vectors(vdev);
+}
+
+/* the config->find_vqs() implementation */
+static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[])
+{
+ int vectors = 0;
+ int i, err;
+
+ /* How many vectors would we like? */
+ for (i = 0; i < nvqs; ++i)
+ if (callbacks[i])
+ ++vectors;
+
+ err = vp_request_vectors(vdev, vectors);
+ if (err)
+ goto error_request;
+
+ for (i = 0; i < nvqs; ++i) {
+ vqs[i] = vp_find_vq(vdev, i, callbacks[i], names[i]);
+ if (IS_ERR(vqs[i]))
+ goto error_find;
+ }
+ return 0;
+
+error_find:
+ vp_del_vqs(vdev);
+
+error_request:
+ return PTR_ERR(vqs[i]);
+}
+
static struct virtio_config_ops virtio_pci_config_ops = {
.get = vp_get,
.set = vp_set,
.get_status = vp_get_status,
.set_status = vp_set_status,
.reset = vp_reset,
- .find_vq = vp_find_vq,
- .del_vq = vp_del_vq,
+ .find_vqs = vp_find_vqs,
+ .del_vqs = vp_del_vqs,
.get_features = vp_get_features,
.finalize_features = vp_finalize_features,
};
@@ -310,7 +547,7 @@ static void virtio_pci_release_dev(struct device *_d)
struct virtio_pci_device *vp_dev = to_vp_device(dev);
struct pci_dev *pci_dev = vp_dev->pci_dev;
- free_irq(pci_dev->irq, vp_dev);
+ vp_del_vqs(dev);
pci_set_drvdata(pci_dev, NULL);
pci_iounmap(pci_dev, vp_dev->ioaddr);
pci_release_regions(pci_dev);
@@ -369,21 +606,13 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
vp_dev->vdev.id.device = pci_dev->subsystem_device;
- /* register a handler for the queue with the PCI device's interrupt */
- err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
- dev_name(&vp_dev->vdev.dev), vp_dev);
- if (err)
- goto out_set_drvdata;
-
/* finally register the virtio device */
err = register_virtio_device(&vp_dev->vdev);
if (err)
- goto out_req_irq;
+ goto out_set_drvdata;
return 0;
-out_req_irq:
- free_irq(pci_dev->irq, vp_dev);
out_set_drvdata:
pci_set_drvdata(pci_dev, NULL);
pci_iounmap(pci_dev, vp_dev->ioaddr);
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 5c52369..a882f26 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -23,21 +23,30 @@
#ifdef DEBUG
/* For development, we want to crash whenever the ring is screwed. */
-#define BAD_RING(_vq, fmt...) \
- do { dev_err(&(_vq)->vq.vdev->dev, fmt); BUG(); } while(0)
+#define BAD_RING(_vq, fmt, args...) \
+ do { \
+ dev_err(&(_vq)->vq.vdev->dev, \
+ "%s:"fmt, (_vq)->vq.name, ##args); \
+ BUG(); \
+ } while (0)
/* Caller is supposed to guarantee no reentry. */
#define START_USE(_vq) \
do { \
if ((_vq)->in_use) \
- panic("in_use = %i\n", (_vq)->in_use); \
+ panic("%s:in_use = %i\n", \
+ (_vq)->vq.name, (_vq)->in_use); \
(_vq)->in_use = __LINE__; \
mb(); \
- } while(0)
+ } while (0)
#define END_USE(_vq) \
do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; mb(); } while(0)
#else
-#define BAD_RING(_vq, fmt...) \
- do { dev_err(&_vq->vq.vdev->dev, fmt); (_vq)->broken = true; } while(0)
+#define BAD_RING(_vq, fmt, args...) \
+ do { \
+ dev_err(&_vq->vq.vdev->dev, \
+ "%s:"fmt, (_vq)->vq.name, ##args); \
+ (_vq)->broken = true; \
+ } while (0)
#define START_USE(vq)
#define END_USE(vq)
#endif
@@ -52,6 +61,9 @@ struct vring_virtqueue
/* Other side has made a mess, don't try any more. */
bool broken;
+ /* Host supports indirect buffers */
+ bool indirect;
+
/* Number of free buffers */
unsigned int num_free;
/* Head of free buffer list. */
@@ -76,6 +88,55 @@ struct vring_virtqueue
#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
+/* Set up an indirect table of descriptors and add it to the queue. */
+static int vring_add_indirect(struct vring_virtqueue *vq,
+ struct scatterlist sg[],
+ unsigned int out,
+ unsigned int in)
+{
+ struct vring_desc *desc;
+ unsigned head;
+ int i;
+
+ desc = kmalloc((out + in) * sizeof(struct vring_desc), GFP_ATOMIC);
+ if (!desc)
+ return vq->vring.num;
+
+ /* Transfer entries from the sg list into the indirect page */
+ for (i = 0; i < out; i++) {
+ desc[i].flags = VRING_DESC_F_NEXT;
+ desc[i].addr = sg_phys(sg);
+ desc[i].len = sg->length;
+ desc[i].next = i+1;
+ sg++;
+ }
+ for (; i < (out + in); i++) {
+ desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
+ desc[i].addr = sg_phys(sg);
+ desc[i].len = sg->length;
+ desc[i].next = i+1;
+ sg++;
+ }
+
+ /* Last one doesn't continue. */
+ desc[i-1].flags &= ~VRING_DESC_F_NEXT;
+ desc[i-1].next = 0;
+
+ /* We're about to use a buffer */
+ vq->num_free--;
+
+ /* Use a single buffer which doesn't continue */
+ head = vq->free_head;
+ vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT;
+ vq->vring.desc[head].addr = virt_to_phys(desc);
+ vq->vring.desc[head].len = i * sizeof(struct vring_desc);
+
+ /* Update free pointer */
+ vq->free_head = vq->vring.desc[head].next;
+
+ return head;
+}
+
static int vring_add_buf(struct virtqueue *_vq,
struct scatterlist sg[],
unsigned int out,
@@ -85,12 +146,21 @@ static int vring_add_buf(struct virtqueue *_vq,
struct vring_virtqueue *vq = to_vvq(_vq);
unsigned int i, avail, head, uninitialized_var(prev);
+ START_USE(vq);
+
BUG_ON(data == NULL);
+
+ /* 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) {
+ head = vring_add_indirect(vq, sg, out, in);
+ if (head != vq->vring.num)
+ goto add_head;
+ }
+
BUG_ON(out + in > vq->vring.num);
BUG_ON(out + in == 0);
- START_USE(vq);
-
if (vq->num_free < out + in) {
pr_debug("Can't add buf len %i - avail = %i\n",
out + in, vq->num_free);
@@ -127,6 +197,7 @@ static int vring_add_buf(struct virtqueue *_vq,
/* Update free pointer */
vq->free_head = i;
+add_head:
/* Set token. */
vq->data[head] = data;
@@ -170,6 +241,11 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
/* Put back on free list: find end */
i = head;
+
+ /* Free the indirect table */
+ if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT)
+ kfree(phys_to_virt(vq->vring.desc[i].addr));
+
while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) {
i = vq->vring.desc[i].next;
vq->num_free++;
@@ -284,7 +360,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *),
- void (*callback)(struct virtqueue *))
+ void (*callback)(struct virtqueue *),
+ const char *name)
{
struct vring_virtqueue *vq;
unsigned int i;
@@ -303,14 +380,18 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
vq->vq.callback = callback;
vq->vq.vdev = vdev;
vq->vq.vq_ops = &vring_vq_ops;
+ vq->vq.name = name;
vq->notify = notify;
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;
#endif
+ vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC);
+
/* No callback? Tell other side not to bother us. */
if (!callback)
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
@@ -327,6 +408,7 @@ EXPORT_SYMBOL_GPL(vring_new_virtqueue);
void vring_del_virtqueue(struct virtqueue *vq)
{
+ list_del(&vq->list);
kfree(to_vvq(vq));
}
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
@@ -338,6 +420,8 @@ void vring_transport_features(struct virtio_device *vdev)
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
switch (i) {
+ case VIRTIO_RING_F_INDIRECT_DESC:
+ break;
default:
/* We don't understand this bit. */
clear_bit(i, vdev->features);
generated by cgit v1.1 at 2024-06-03 03:42:27 +0000