From ef688e151c00e5d529703be9a04fd506df8bc54e Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 12 Jun 2009 22:16:35 -0600 Subject: virtio: meet virtio spec by finalizing features before using device Virtio devices are supposed to negotiate features before they start using the device, but the current code doesn't do this. This is because the driver's probe() function invariably has to add buffers to a virtqueue, or probe the disk (virtio_blk). This currently doesn't matter since no existing backend is strict about the feature negotiation. But it's possible to imagine a future feature which completely changes how a device operates: in this case, we'd need to acknowledge it before using the device. Signed-off-by: Rusty Russell --- drivers/virtio/virtio.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 018c070a357f..6b6810364860 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -118,13 +118,14 @@ 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; } -- cgit v1.2.2 From 9499f5e7ed5224c40706f0cec6542a9916bc7606 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 12 Jun 2009 22:16:35 -0600 Subject: virtio: add names to virtqueue struct, mapping from devices to queues. Add a linked list of all virtqueues for a virtio device: this helps for debugging and is also needed for upcoming interface change. Also, add a "name" field for clearer debug messages. Signed-off-by: Rusty Russell --- drivers/virtio/virtio.c | 2 ++ drivers/virtio/virtio_balloon.c | 4 ++-- drivers/virtio/virtio_pci.c | 5 +++-- drivers/virtio/virtio_ring.c | 27 ++++++++++++++++++++------- 4 files changed, 27 insertions(+), 11 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 6b6810364860..3f52c767dfe9 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -186,6 +186,8 @@ 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 9c76a061a04d..0fa73b4d18b0 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -218,13 +218,13 @@ 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); + vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack, "inflate"); if (IS_ERR(vb->inflate_vq)) { err = PTR_ERR(vb->inflate_vq); goto out_free_vb; } - vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack); + vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack, "deflate"); if (IS_ERR(vb->deflate_vq)) { err = PTR_ERR(vb->deflate_vq); goto out_del_inflate_vq; diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 330aacbdec1f..be4047abd5ba 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -208,7 +208,8 @@ static irqreturn_t vp_interrupt(int irq, void *opaque) /* 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; @@ -247,7 +248,7 @@ 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; diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 5c52369ab9bb..579fa693d5d0 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 @@ -284,7 +293,8 @@ 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; @@ -303,10 +313,12 @@ 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 @@ -327,6 +339,7 @@ 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); -- cgit v1.2.2 From d2a7ddda9ffb1c8961abff6714b0f1eb925c120f Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Fri, 12 Jun 2009 22:16:36 -0600 Subject: virtio: find_vqs/del_vqs virtio operations This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations, and updates all drivers. This is needed for MSI support, because MSI needs to know the total number of vectors upfront. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell (+ lguest/9p compile fixes) --- drivers/virtio/virtio_balloon.c | 27 +++++++++++---------------- drivers/virtio/virtio_pci.c | 37 ++++++++++++++++++++++++++++++------- 2 files changed, 41 insertions(+), 23 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 0fa73b4d18b0..26b278264796 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, "inflate"); - 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, "deflate"); - 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 be4047abd5ba..027f13fbe493 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -276,11 +276,7 @@ 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; - - spin_lock_irqsave(&vp_dev->lock, flags); - list_del(&info->node); - spin_unlock_irqrestore(&vp_dev->lock, flags); + unsigned long size; vring_del_virtqueue(vq); @@ -293,14 +289,41 @@ static void vp_del_vq(struct virtqueue *vq) kfree(info); } +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); +} + +static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + int i; + + for (i = 0; i < nvqs; ++i) { + vqs[i] = vp_find_vq(vdev, i, callbacks[i], names[i]); + if (IS_ERR(vqs[i])) + goto error; + } + return 0; + +error: + vp_del_vqs(vdev); + 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, }; -- cgit v1.2.2 From 77cf524654a886e0fbbf03b16b44f048deef7b0c Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 14 May 2009 13:55:31 +0300 Subject: virtio_pci: split up vp_interrupt This reorganizes virtio-pci code in vp_interrupt slightly, so that it's easier to add per-vq MSI support on top. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 53 +++++++++++++++++++++++++++++---------------- 1 file changed, 34 insertions(+), 19 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 027f13fbe493..951e673e50a4 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -164,6 +164,37 @@ 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 +204,6 @@ 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 @@ -187,23 +215,10 @@ 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 (drv && drv->config_changed) - drv->config_changed(&vp_dev->vdev); - } + if (isr & VIRTIO_PCI_ISR_CONFIG) + vp_config_changed(irq, opaque); - 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; + return vp_vring_interrupt(irq, opaque); } /* the config->find_vq() implementation */ -- cgit v1.2.2 From 82af8ce84ed65d2fb6d8c017d3f2bbbf161061fb Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 14 May 2009 13:55:41 +0300 Subject: virtio_pci: optional MSI-X support This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin Acked-by: Anthony Liguori Signed-off-by: Rusty Russell (+ whitespace, style) --- drivers/virtio/virtio_pci.c | 228 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 209 insertions(+), 19 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 951e673e50a4..193c8f0e5cc5 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; @@ -221,7 +246,122 @@ static irqreturn_t vp_interrupt(int irq, void *opaque) return vp_vring_interrupt(irq, opaque); } -/* the config->find_vq() implementation */ +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; + } + + 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); + } +} + +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; +} + static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index, void (*callback)(struct virtqueue *vq), const char *name) @@ -230,7 +370,7 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index, 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 */ @@ -249,6 +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); @@ -272,12 +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); @@ -286,17 +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 size; + 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)); @@ -304,30 +486,46 @@ 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 i; + 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; + goto error_find; } return 0; -error: +error_find: vp_del_vqs(vdev); + +error_request: return PTR_ERR(vqs[i]); } @@ -349,7 +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); @@ -408,21 +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); -- cgit v1.2.2 From a92892825a122a74ddad1d408fa27132e28b05ae Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 12 Jun 2009 22:16:37 -0600 Subject: virtio: expose features in sysfs Each device negotiates feature bits; expose these in sysfs to help diagnostics and debugging. Signed-off-by: Rusty Russell --- drivers/virtio/virtio.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 3f52c767dfe9..bd0745250fd9 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -31,11 +31,27 @@ 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 }; -- cgit v1.2.2 From 9fa29b9df32ba4db055f3977933cd0c1b8fe67cd Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Mon, 11 May 2009 18:11:45 +0100 Subject: virtio: indirect ring entries (VIRTIO_RING_F_INDIRECT_DESC) Add a new feature flag for indirect ring entries. These are ring entries which point to a table of buffer descriptors. The idea here is to increase the ring capacity by allowing a larger effective ring size whereby the ring size dictates the number of requests that may be outstanding, rather than the size of those requests. This should be most effective in the case of block I/O where we can potentially benefit by concurrently dispatching a large number of large requests. Even in the simple case of single segment block requests, this results in a threefold increase in ring capacity. Signed-off-by: Mark McLoughlin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 75 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 73 insertions(+), 2 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 579fa693d5d0..a882f2606515 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -61,6 +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. */ @@ -85,6 +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, @@ -94,12 +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); @@ -136,6 +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; @@ -179,6 +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++; @@ -323,6 +390,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, 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; @@ -351,6 +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); -- cgit v1.2.2 From c89e80168ba1ed37627fe03116b0cf8474dcb7e0 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 26 May 2009 15:46:09 +0200 Subject: virtio: fix id_matching for virtio drivers This bug never appeared, since all current virtio drivers use VIRTIO_DEV_ANY_ID for the vendor field. If a real vendor would be used, the check in virtio_id_match is wrong - it returns 0 if id->vendor == dev->id.vendor. Signed-off-by: Christian Borntraeger Signed-off-by: Rusty Russell --- drivers/virtio/virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index bd0745250fd9..22642a255d32 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -61,7 +61,7 @@ static inline int virtio_id_match(const struct virtio_device *dev, if (id->device != dev->id.device) 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 -- cgit v1.2.2 From e3353853730eb99c56b7b0aed1667d51c0e3699a Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 26 May 2009 15:46:10 +0200 Subject: virtio: enhance id_matching for virtio drivers This patch allows a virtio driver to use VIRTIO_DEV_ANY_ID for the device id. This will be used by a test module that can be bound to any virtio device. Signed-off-by: Christian Borntraeger Signed-off-by: Rusty Russell --- drivers/virtio/virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 22642a255d32..3a43ebf83a49 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -58,7 +58,7 @@ static struct device_attribute virtio_dev_attrs[] = { 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; -- cgit v1.2.2