diff options
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/Kconfig | 36 | ||||
| -rw-r--r-- | drivers/virtio/Makefile | 3 | ||||
| -rw-r--r-- | drivers/virtio/config.c | 1 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 77 | ||||
| -rw-r--r-- | drivers/virtio/virtio_balloon.c | 382 | ||||
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 223 | ||||
| -rw-r--r-- | drivers/virtio/virtio_pci.c | 186 | ||||
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 494 |
8 files changed, 1084 insertions, 318 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 1a61939b85f..c6683f2e396 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -1,19 +1,16 @@ -# Virtio always gets selected by whoever wants it. config VIRTIO tristate - -# Similarly the virtio ring implementation. -config VIRTIO_RING - tristate - depends on VIRTIO + ---help--- + This option is selected by any driver which implements the virtio + bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_LGUEST, + CONFIG_RPMSG or CONFIG_S390_GUEST. menu "Virtio drivers" config VIRTIO_PCI - tristate "PCI driver for virtio devices (EXPERIMENTAL)" - depends on PCI && EXPERIMENTAL + tristate "PCI driver for virtio devices" + depends on PCI select VIRTIO - select VIRTIO_RING ---help--- This drivers provides support for virtio based paravirtual device drivers over PCI. This requires that your VMM has appropriate PCI @@ -26,9 +23,8 @@ config VIRTIO_PCI If unsure, say M. config VIRTIO_BALLOON - tristate "Virtio balloon driver (EXPERIMENTAL)" - select VIRTIO - select VIRTIO_RING + tristate "Virtio balloon driver" + depends on VIRTIO ---help--- This driver supports increasing and decreasing the amount of memory within a KVM guest. @@ -36,14 +32,24 @@ config VIRTIO_BALLOON If unsure, say M. config VIRTIO_MMIO - tristate "Platform bus driver for memory mapped virtio devices (EXPERIMENTAL)" - depends on HAS_IOMEM && EXPERIMENTAL + tristate "Platform bus driver for memory mapped virtio devices" + depends on HAS_IOMEM select VIRTIO - select VIRTIO_RING ---help--- This drivers provides support for memory mapped virtio platform device driver. If unsure, say N. +config VIRTIO_MMIO_CMDLINE_DEVICES + bool "Memory mapped virtio devices parameter parsing" + depends on VIRTIO_MMIO + ---help--- + Allow virtio-mmio devices instantiation via the kernel command line + or module parameters. Be aware that using incorrect parameters (base + address in particular) can crash your system - you have been warned. + See Documentation/kernel-parameters.txt for details. + + If unsure, say 'N'. + endmenu diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 5a4c63cfd38..9076635697b 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -1,5 +1,4 @@ -obj-$(CONFIG_VIRTIO) += virtio.o -obj-$(CONFIG_VIRTIO_RING) += virtio_ring.o +obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o diff --git a/drivers/virtio/config.c b/drivers/virtio/config.c index 983d482fba4..f70bcd2ff98 100644 --- a/drivers/virtio/config.c +++ b/drivers/virtio/config.c @@ -9,5 +9,4 @@ #include <linux/virtio.h> #include <linux/virtio_config.h> #include <linux/bug.h> -#include <asm/system.h> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 984c501c258..fed0ce198ae 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -2,40 +2,48 @@ #include <linux/spinlock.h> #include <linux/virtio_config.h> #include <linux/module.h> +#include <linux/idr.h> /* Unique numbering for virtio devices. */ -static unsigned int dev_index; +static DEFINE_IDA(virtio_index_ida); static ssize_t device_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "0x%04x\n", dev->id.device); } +static DEVICE_ATTR_RO(device); + static ssize_t vendor_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "0x%04x\n", dev->id.vendor); } +static DEVICE_ATTR_RO(vendor); + static ssize_t status_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); } +static DEVICE_ATTR_RO(status); + static ssize_t modalias_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - + struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "virtio:d%08Xv%08X\n", dev->id.device, dev->id.vendor); } +static DEVICE_ATTR_RO(modalias); + 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); + struct virtio_device *dev = dev_to_virtio(_d); unsigned int i; ssize_t len = 0; @@ -47,14 +55,17 @@ static ssize_t features_show(struct device *_d, 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 DEVICE_ATTR_RO(features); + +static struct attribute *virtio_dev_attrs[] = { + &dev_attr_device.attr, + &dev_attr_vendor.attr, + &dev_attr_status.attr, + &dev_attr_modalias.attr, + &dev_attr_features.attr, + NULL, }; +ATTRIBUTE_GROUPS(virtio_dev); static inline int virtio_id_match(const struct virtio_device *dev, const struct virtio_device_id *id) @@ -70,10 +81,10 @@ static inline int virtio_id_match(const struct virtio_device *dev, static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) { unsigned int i; - struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_dv); const struct virtio_device_id *ids; - ids = container_of(_dr, struct virtio_driver, driver)->id_table; + ids = drv_to_virtio(_dr)->id_table; for (i = 0; ids[i].device; i++) if (virtio_id_match(dev, &ids[i])) return 1; @@ -82,7 +93,7 @@ static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) { - struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_dv); return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", dev->id.device, dev->id.vendor); @@ -97,8 +108,7 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev, unsigned int fbit) { unsigned int i; - struct virtio_driver *drv = container_of(vdev->dev.driver, - struct virtio_driver, driver); + struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); for (i = 0; i < drv->feature_table_size; i++) if (drv->feature_table[i] == fbit) @@ -110,9 +120,8 @@ EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); static int virtio_dev_probe(struct device *_d) { int err, i; - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - struct virtio_driver *drv = container_of(dev->dev.driver, - struct virtio_driver, driver); + struct virtio_device *dev = dev_to_virtio(_d); + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); u32 device_features; /* We have a driver! */ @@ -140,22 +149,24 @@ static int virtio_dev_probe(struct device *_d) err = drv->probe(dev); if (err) add_status(dev, VIRTIO_CONFIG_S_FAILED); - else + else { add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); + if (drv->scan) + drv->scan(dev); + } return err; } static int virtio_dev_remove(struct device *_d) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - struct virtio_driver *drv = container_of(dev->dev.driver, - struct virtio_driver, driver); + struct virtio_device *dev = dev_to_virtio(_d); + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); drv->remove(dev); /* Driver should have reset device. */ - BUG_ON(dev->config->get_status(dev)); + WARN_ON_ONCE(dev->config->get_status(dev)); /* Acknowledge the device's existence again. */ add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); @@ -165,7 +176,7 @@ static int virtio_dev_remove(struct device *_d) static struct bus_type virtio_bus = { .name = "virtio", .match = virtio_dev_match, - .dev_attrs = virtio_dev_attrs, + .dev_groups = virtio_dev_groups, .uevent = virtio_uevent, .probe = virtio_dev_probe, .remove = virtio_dev_remove, @@ -193,7 +204,11 @@ int register_virtio_device(struct virtio_device *dev) dev->dev.bus = &virtio_bus; /* Assign a unique device index and hence name. */ - dev->index = dev_index++; + err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); + if (err < 0) + goto out; + + dev->index = err; dev_set_name(&dev->dev, "virtio%u", dev->index); /* We always start by resetting the device, in case a previous @@ -208,6 +223,7 @@ int register_virtio_device(struct virtio_device *dev) /* device_register() causes the bus infrastructure to look for a * matching driver. */ err = device_register(&dev->dev); +out: if (err) add_status(dev, VIRTIO_CONFIG_S_FAILED); return err; @@ -216,7 +232,10 @@ EXPORT_SYMBOL_GPL(register_virtio_device); void unregister_virtio_device(struct virtio_device *dev) { + int index = dev->index; /* save for after device release */ + device_unregister(&dev->dev); + ida_simple_remove(&virtio_index_ida, index); } EXPORT_SYMBOL_GPL(unregister_virtio_device); diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 94fd738a774..25ebe8eecdb 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> @@ -26,6 +27,15 @@ #include <linux/delay.h> #include <linux/slab.h> #include <linux/module.h> +#include <linux/balloon_compaction.h> + +/* + * Balloon device works in 4K page units. So each page is pointed to by + * multiple balloon pages. All memory counters in this driver are in balloon + * page units. + */ +#define VIRTIO_BALLOON_PAGES_PER_PAGE (unsigned)(PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT) +#define VIRTIO_BALLOON_ARRAY_PFNS_MAX 256 struct virtio_balloon { @@ -39,15 +49,24 @@ struct virtio_balloon struct task_struct *thread; /* Waiting for host to ack the pages we released. */ - struct completion acked; + wait_queue_head_t acked; - /* The pages we've told the Host we're not using. */ + /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; - struct list_head pages; + /* + * The pages we've told the Host we're not using are enqueued + * at vb_dev_info->pages list. + * Each page on this list adds VIRTIO_BALLOON_PAGES_PER_PAGE + * to num_pages above. + */ + struct balloon_dev_info *vb_dev_info; + + /* Synchronize access/update to this struct virtio_balloon elements */ + struct mutex balloon_lock; /* The array of pfns we tell the Host about. */ unsigned int num_pfns; - u32 pfns[256]; + u32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; /* Memory statistics */ int need_stats_update; @@ -65,97 +84,116 @@ static u32 page_to_balloon_pfn(struct page *page) BUILD_BUG_ON(PAGE_SHIFT < VIRTIO_BALLOON_PFN_SHIFT); /* Convert pfn from Linux page size to balloon page size. */ - return pfn >> (PAGE_SHIFT - VIRTIO_BALLOON_PFN_SHIFT); + return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE; +} + +static struct page *balloon_pfn_to_page(u32 pfn) +{ + BUG_ON(pfn % VIRTIO_BALLOON_PAGES_PER_PAGE); + return pfn_to_page(pfn / VIRTIO_BALLOON_PAGES_PER_PAGE); } static void balloon_ack(struct virtqueue *vq) { - struct virtio_balloon *vb; - unsigned int len; + struct virtio_balloon *vb = vq->vdev->priv; - vb = virtqueue_get_buf(vq, &len); - if (vb) - complete(&vb->acked); + wake_up(&vb->acked); } static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq) { struct scatterlist sg; + unsigned int len; sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); - 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) - BUG(); + virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL); virtqueue_kick(vq); /* When host has read buffer, this completes via balloon_ack */ - wait_for_completion(&vb->acked); + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); +} + +static void set_page_pfns(u32 pfns[], struct page *page) +{ + unsigned int i; + + /* Set balloon pfns pointing at this page. + * Note that the first pfn points at start of the page. */ + for (i = 0; i < VIRTIO_BALLOON_PAGES_PER_PAGE; i++) + pfns[i] = page_to_balloon_pfn(page) + i; } static void fill_balloon(struct virtio_balloon *vb, size_t num) { + struct balloon_dev_info *vb_dev_info = vb->vb_dev_info; + /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); - for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) { - struct page *page = alloc_page(GFP_HIGHUSER | __GFP_NORETRY | - __GFP_NOMEMALLOC | __GFP_NOWARN); + mutex_lock(&vb->balloon_lock); + for (vb->num_pfns = 0; vb->num_pfns < num; + vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { + struct page *page = balloon_page_enqueue(vb_dev_info); + if (!page) { - if (printk_ratelimit()) - dev_printk(KERN_INFO, &vb->vdev->dev, - "Out of puff! Can't get %zu pages\n", - num); + dev_info_ratelimited(&vb->vdev->dev, + "Out of puff! Can't get %u pages\n", + VIRTIO_BALLOON_PAGES_PER_PAGE); /* Sleep for at least 1/5 of a second before retry. */ msleep(200); break; } - vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page); - totalram_pages--; - vb->num_pages++; - list_add(&page->lru, &vb->pages); + set_page_pfns(vb->pfns + vb->num_pfns, page); + vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; + adjust_managed_page_count(page, -1); } - /* Didn't get any? Oh well. */ - if (vb->num_pfns == 0) - return; - - tell_host(vb, vb->inflate_vq); + /* Did we get any? */ + if (vb->num_pfns != 0) + tell_host(vb, vb->inflate_vq); + mutex_unlock(&vb->balloon_lock); } static void release_pages_by_pfn(const u32 pfns[], unsigned int num) { unsigned int i; - for (i = 0; i < num; i++) { - __free_page(pfn_to_page(pfns[i])); - totalram_pages++; + /* Find pfns pointing at start of each page, get pages and free them. */ + for (i = 0; i < num; i += VIRTIO_BALLOON_PAGES_PER_PAGE) { + struct page *page = balloon_pfn_to_page(pfns[i]); + balloon_page_free(page); + adjust_managed_page_count(page, 1); } } static void leak_balloon(struct virtio_balloon *vb, size_t num) { struct page *page; + struct balloon_dev_info *vb_dev_info = vb->vb_dev_info; /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); - for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) { - page = list_first_entry(&vb->pages, struct page, lru); - list_del(&page->lru); - vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page); - vb->num_pages--; + mutex_lock(&vb->balloon_lock); + for (vb->num_pfns = 0; vb->num_pfns < num; + vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { + page = balloon_page_dequeue(vb_dev_info); + if (!page) + break; + set_page_pfns(vb->pfns + vb->num_pfns, page); + vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE; } - /* * Note that if * virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST); * is true, we *have* to do it in this order */ - tell_host(vb, vb->deflate_vq); + if (vb->num_pfns != 0) + tell_host(vb, vb->deflate_vq); + mutex_unlock(&vb->balloon_lock); release_pages_by_pfn(vb->pfns, vb->num_pfns); } @@ -200,12 +238,8 @@ static void update_balloon_stats(struct virtio_balloon *vb) */ static void stats_request(struct virtqueue *vq) { - struct virtio_balloon *vb; - unsigned int len; + struct virtio_balloon *vb = vq->vdev->priv; - vb = virtqueue_get_buf(vq, &len); - if (!vb) - return; vb->need_stats_update = 1; wake_up(&vb->config_change); } @@ -214,14 +248,16 @@ static void stats_handle_request(struct virtio_balloon *vb) { struct virtqueue *vq; struct scatterlist sg; + unsigned int len; vb->need_stats_update = 0; update_balloon_stats(vb); vq = vb->stats_vq; + if (!virtqueue_get_buf(vq, &len)) + return; sg_init_one(&sg, vb->stats, sizeof(vb->stats)); - if (virtqueue_add_buf(vq, &sg, 1, 0, vb) < 0) - BUG(); + virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL); virtqueue_kick(vq); } @@ -234,20 +270,21 @@ static void virtballoon_changed(struct virtio_device *vdev) static inline s64 towards_target(struct virtio_balloon *vb) { - u32 v; - vb->vdev->config->get(vb->vdev, - offsetof(struct virtio_balloon_config, num_pages), - &v, sizeof(v)); - return (s64)v - vb->num_pages; + __le32 v; + s64 target; + + virtio_cread(vb->vdev, struct virtio_balloon_config, num_pages, &v); + + target = le32_to_cpu(v); + return target - vb->num_pages; } static void update_balloon_size(struct virtio_balloon *vb) { __le32 actual = cpu_to_le32(vb->num_pages); - vb->vdev->config->set(vb->vdev, - offsetof(struct virtio_balloon_config, actual), - &actual, sizeof(actual)); + virtio_cwrite(vb->vdev, struct virtio_balloon_config, actual, + &actual); } static int balloon(void *_vballoon) @@ -271,36 +308,31 @@ static int balloon(void *_vballoon) else if (diff < 0) leak_balloon(vb, -diff); update_balloon_size(vb); + + /* + * For large balloon changes, we could spend a lot of time + * and always have work to do. Be nice if preempt disabled. + */ + cond_resched(); } 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]; @@ -310,13 +342,134 @@ static int virtballoon_probe(struct virtio_device *vdev) /* * Prime this virtqueue with one buffer so the hypervisor can - * use it to signal us later. + * use it to signal us later (it can't be broken yet!). */ sg_init_one(&sg, vb->stats, sizeof vb->stats); - if (virtqueue_add_buf(vb->stats_vq, &sg, 1, 0, vb) < 0) + if (virtqueue_add_outbuf(vb->stats_vq, &sg, 1, vb, GFP_KERNEL) + < 0) BUG(); virtqueue_kick(vb->stats_vq); } + return 0; +} + +static const struct address_space_operations virtio_balloon_aops; +#ifdef CONFIG_BALLOON_COMPACTION +/* + * virtballoon_migratepage - perform the balloon page migration on behalf of + * a compation thread. (called under page lock) + * @mapping: the page->mapping which will be assigned to the new migrated page. + * @newpage: page that will replace the isolated page after migration finishes. + * @page : the isolated (old) page that is about to be migrated to newpage. + * @mode : compaction mode -- not used for balloon page migration. + * + * After a ballooned page gets isolated by compaction procedures, this is the + * function that performs the page migration on behalf of a compaction thread + * The page migration for virtio balloon is done in a simple swap fashion which + * follows these two macro steps: + * 1) insert newpage into vb->pages list and update the host about it; + * 2) update the host about the old page removed from vb->pages list; + * + * This function preforms the balloon page migration task. + * Called through balloon_mapping->a_ops->migratepage + */ +static int virtballoon_migratepage(struct address_space *mapping, + struct page *newpage, struct page *page, enum migrate_mode mode) +{ + struct balloon_dev_info *vb_dev_info = balloon_page_device(page); + struct virtio_balloon *vb; + unsigned long flags; + + BUG_ON(!vb_dev_info); + + vb = vb_dev_info->balloon_device; + + /* + * In order to avoid lock contention while migrating pages concurrently + * to leak_balloon() or fill_balloon() we just give up the balloon_lock + * this turn, as it is easier to retry the page migration later. + * This also prevents fill_balloon() getting stuck into a mutex + * recursion in the case it ends up triggering memory compaction + * while it is attempting to inflate the ballon. + */ + if (!mutex_trylock(&vb->balloon_lock)) + return -EAGAIN; + + /* balloon's page migration 1st step -- inflate "newpage" */ + spin_lock_irqsave(&vb_dev_info->pages_lock, flags); + balloon_page_insert(newpage, mapping, &vb_dev_info->pages); + vb_dev_info->isolated_pages--; + spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags); + vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE; + set_page_pfns(vb->pfns, newpage); + tell_host(vb, vb->inflate_vq); + + /* + * balloon's page migration 2nd step -- deflate "page" + * + * It's safe to delete page->lru here because this page is at + * an isolated migration list, and this step is expected to happen here + */ + balloon_page_delete(page); + vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE; + set_page_pfns(vb->pfns, page); + tell_host(vb, vb->deflate_vq); + + mutex_unlock(&vb->balloon_lock); + + return MIGRATEPAGE_BALLOON_SUCCESS; +} + +/* define the balloon_mapping->a_ops callback to allow balloon page migration */ +static const struct address_space_operations virtio_balloon_aops = { + .migratepage = virtballoon_migratepage, +}; +#endif /* CONFIG_BALLOON_COMPACTION */ + +static int virtballoon_probe(struct virtio_device *vdev) +{ + struct virtio_balloon *vb; + struct address_space *vb_mapping; + struct balloon_dev_info *vb_devinfo; + int err; + + vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL); + if (!vb) { + err = -ENOMEM; + goto out; + } + + vb->num_pages = 0; + mutex_init(&vb->balloon_lock); + init_waitqueue_head(&vb->config_change); + init_waitqueue_head(&vb->acked); + vb->vdev = vdev; + vb->need_stats_update = 0; + + vb_devinfo = balloon_devinfo_alloc(vb); + if (IS_ERR(vb_devinfo)) { + err = PTR_ERR(vb_devinfo); + goto out_free_vb; + } + + vb_mapping = balloon_mapping_alloc(vb_devinfo, + (balloon_compaction_check()) ? + &virtio_balloon_aops : NULL); + if (IS_ERR(vb_mapping)) { + /* + * IS_ERR(vb_mapping) && PTR_ERR(vb_mapping) == -EOPNOTSUPP + * This means !CONFIG_BALLOON_COMPACTION, otherwise we get off. + */ + err = PTR_ERR(vb_mapping); + if (err != -EOPNOTSUPP) + goto out_free_vb_devinfo; + } + + vb->vb_dev_info = vb_devinfo; + + err = init_vqs(vb); + if (err) + goto out_free_vb_mapping; vb->thread = kthread_run(balloon, vb, "vballoon"); if (IS_ERR(vb->thread)) { @@ -328,29 +481,69 @@ static int virtballoon_probe(struct virtio_device *vdev) out_del_vqs: vdev->config->del_vqs(vdev); +out_free_vb_mapping: + balloon_mapping_free(vb_mapping); +out_free_vb_devinfo: + balloon_devinfo_free(vb_devinfo); out_free_vb: kfree(vb); out: return err; } -static void __devexit virtballoon_remove(struct virtio_device *vdev) +static void remove_common(struct virtio_balloon *vb) { - struct virtio_balloon *vb = vdev->priv; - - kthread_stop(vb->thread); - /* There might be pages left in the balloon: free them. */ while (vb->num_pages) leak_balloon(vb, vb->num_pages); + update_balloon_size(vb); /* Now we reset the device so we can clean up the queues. */ - vdev->config->reset(vdev); + vb->vdev->config->reset(vb->vdev); - vdev->config->del_vqs(vdev); + vb->vdev->config->del_vqs(vb->vdev); +} + +static void virtballoon_remove(struct virtio_device *vdev) +{ + struct virtio_balloon *vb = vdev->priv; + + kthread_stop(vb->thread); + remove_common(vb); + balloon_mapping_free(vb->vb_dev_info->mapping); + balloon_devinfo_free(vb->vb_dev_info); kfree(vb); } +#ifdef CONFIG_PM_SLEEP +static int virtballoon_freeze(struct virtio_device *vdev) +{ + struct virtio_balloon *vb = vdev->priv; + + /* + * The kthread is already frozen by the PM core before this + * function is called. + */ + + remove_common(vb); + return 0; +} + +static int virtballoon_restore(struct virtio_device *vdev) +{ + struct virtio_balloon *vb = vdev->priv; + int ret; + + ret = init_vqs(vdev->priv); + if (ret) + return ret; + + fill_balloon(vb, towards_target(vb)); + update_balloon_size(vb); + return 0; +} +#endif + static unsigned int features[] = { VIRTIO_BALLOON_F_MUST_TELL_HOST, VIRTIO_BALLOON_F_STATS_VQ, @@ -363,22 +556,15 @@ static struct virtio_driver virtio_balloon_driver = { .driver.owner = THIS_MODULE, .id_table = id_table, .probe = virtballoon_probe, - .remove = __devexit_p(virtballoon_remove), + .remove = virtballoon_remove, .config_changed = virtballoon_changed, +#ifdef CONFIG_PM_SLEEP + .freeze = virtballoon_freeze, + .restore = virtballoon_restore, +#endif }; -static int __init init(void) -{ - return register_virtio_driver(&virtio_balloon_driver); -} - -static void __exit fini(void) -{ - unregister_virtio_driver(&virtio_balloon_driver); -} -module_init(init); -module_exit(fini); - +module_virtio_driver(virtio_balloon_driver); MODULE_DEVICE_TABLE(virtio, id_table); MODULE_DESCRIPTION("Virtio balloon driver"); MODULE_LICENSE("GPL"); diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 7317dc2ec42..c600ccfd692 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -6,6 +6,50 @@ * This module allows virtio devices to be used over a virtual, memory mapped * platform device. * + * The guest device(s) may be instantiated in one of three equivalent ways: + * + * 1. Static platform device in board's code, eg.: + * + * static struct platform_device v2m_virtio_device = { + * .name = "virtio-mmio", + * .id = -1, + * .num_resources = 2, + * .resource = (struct resource []) { + * { + * .start = 0x1001e000, + * .end = 0x1001e0ff, + * .flags = IORESOURCE_MEM, + * }, { + * .start = 42 + 32, + * .end = 42 + 32, + * .flags = IORESOURCE_IRQ, + * }, + * } + * }; + * + * 2. Device Tree node, eg.: + * + * virtio_block@1e000 { + * compatible = "virtio,mmio"; + * reg = <0x1e000 0x100>; + * interrupts = <42>; + * } + * + * 3. Kernel module (or command line) parameter. Can be used more than once - + * one device will be created for each one. Syntax: + * + * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>] + * where: + * <size> := size (can use standard suffixes like K, M or G) + * <baseaddr> := physical base address + * <irq> := interrupt number (as passed to request_irq()) + * <id> := (optional) platform device id + * eg.: + * virtio_mmio.device=0x100@0x100b0000:48 \ + * virtio_mmio.device=1K@0x1001e000:74 + * + * + * * Registers layout (all 32-bit wide): * * offset d. name description @@ -31,7 +75,7 @@ * * 0x050 W QueueNotify Queue notifier * 0x060 R InterruptStatus Interrupt status register - * 0x060 W InterruptACK Interrupt acknowledge register + * 0x064 W InterruptACK Interrupt acknowledge register * 0x070 RW Status Device status register * * 0x100+ RW Device-specific configuration space @@ -42,6 +86,8 @@ * See the COPYING file in the top-level directory. */ +#define pr_fmt(fmt) "virtio-mmio: " fmt + #include <linux/highmem.h> #include <linux/interrupt.h> #include <linux/io.h> @@ -85,9 +131,6 @@ struct virtio_mmio_vq_info { /* the number of entries in the queue */ unsigned int num; - /* the index of the queue */ - int queue_index; - /* the virtual address of the ring queue */ void *queue; @@ -176,14 +219,14 @@ static void vm_reset(struct virtio_device *vdev) /* Transport interface */ /* the notify function used when creating a virt queue */ -static void vm_notify(struct virtqueue *vq) +static bool vm_notify(struct virtqueue *vq) { struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); - struct virtio_mmio_vq_info *info = vq->priv; /* We write the queue's selector into the notification register to * signal the other end */ - writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); + writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); + return true; } /* Notify all virtqueues on an interrupt. */ @@ -224,6 +267,7 @@ static void vm_del_vq(struct virtqueue *vq) struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); struct virtio_mmio_vq_info *info = vq->priv; unsigned long flags, size; + unsigned int index = vq->index; spin_lock_irqsave(&vm_dev->lock, flags); list_del(&info->node); @@ -232,7 +276,7 @@ static void vm_del_vq(struct virtqueue *vq) vring_del_virtqueue(vq); /* Select and deactivate the queue */ - writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); + writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN)); @@ -263,6 +307,9 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, unsigned long flags, size; int err; + if (!name) + return NULL; + /* Select the queue we're interested in */ writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); @@ -278,7 +325,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, err = -ENOMEM; goto error_kmalloc; } - info->queue_index = index; /* Allocate pages for the queue - start with a queue as big as * possible (limited by maximum size allowed by device), drop down @@ -286,11 +332,21 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, * and two rings (which makes it "alignment_size * 2") */ info->num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); + + /* If the device reports a 0 entry queue, we won't be able to + * use it to perform I/O, and vring_new_virtqueue() can't create + * empty queues anyway, so don't bother to set up the device. + */ + if (info->num == 0) { + err = -ENOENT; + goto error_alloc_pages; + } + while (1) { size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN)); - /* Already smallest possible allocation? */ - if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) { + /* Did the last iter shrink the queue below minimum size? */ + if (size < VIRTIO_MMIO_VRING_ALIGN * 2) { err = -ENOMEM; goto error_alloc_pages; } @@ -310,8 +366,8 @@ 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(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev, + true, info->queue, vm_notify, callback, name); if (!vq) { err = -ENOMEM; goto error_new_virtqueue; @@ -361,9 +417,14 @@ static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs, return 0; } +static const char *vm_bus_name(struct virtio_device *vdev) +{ + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); + return vm_dev->pdev->name; +} -static struct virtio_config_ops virtio_mmio_config_ops = { +static const struct virtio_config_ops virtio_mmio_config_ops = { .get = vm_get, .set = vm_set, .get_status = vm_get_status, @@ -373,13 +434,14 @@ static struct virtio_config_ops virtio_mmio_config_ops = { .del_vqs = vm_del_vqs, .get_features = vm_get_features, .finalize_features = vm_finalize_features, + .bus_name = vm_bus_name, }; /* Platform device */ -static int __devinit virtio_mmio_probe(struct platform_device *pdev) +static int virtio_mmio_probe(struct platform_device *pdev) { struct virtio_mmio_device *vm_dev; struct resource *mem; @@ -409,7 +471,7 @@ static int __devinit virtio_mmio_probe(struct platform_device *pdev) /* Check magic value */ magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); - if (memcmp(&magic, "virt", 4) != 0) { + if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); return -ENODEV; } @@ -432,7 +494,7 @@ static int __devinit virtio_mmio_probe(struct platform_device *pdev) return register_virtio_device(&vm_dev->vdev); } -static int __devexit virtio_mmio_remove(struct platform_device *pdev) +static int virtio_mmio_remove(struct platform_device *pdev) { struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); @@ -443,6 +505,130 @@ static int __devexit virtio_mmio_remove(struct platform_device *pdev) +/* Devices list parameter */ + +#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) + +static struct device vm_cmdline_parent = { + .init_name = "virtio-mmio-cmdline", +}; + +static int vm_cmdline_parent_registered; +static int vm_cmdline_id; + +static int vm_cmdline_set(const char *device, + const struct kernel_param *kp) +{ + int err; + struct resource resources[2] = {}; + char *str; + long long int base, size; + unsigned int irq; + int processed, consumed = 0; + struct platform_device *pdev; + + /* Consume "size" part of the command line parameter */ + size = memparse(device, &str); + + /* Get "@<base>:<irq>[:<id>]" chunks */ + processed = sscanf(str, "@%lli:%u%n:%d%n", + &base, &irq, &consumed, + &vm_cmdline_id, &consumed); + + /* + * sscanf() must processes at least 2 chunks; also there + * must be no extra characters after the last chunk, so + * str[consumed] must be '\0' + */ + if (processed < 2 || str[consumed]) + return -EINVAL; + + resources[0].flags = IORESOURCE_MEM; + resources[0].start = base; + resources[0].end = base + size - 1; + + resources[1].flags = IORESOURCE_IRQ; + resources[1].start = resources[1].end = irq; + + if (!vm_cmdline_parent_registered) { + err = device_register(&vm_cmdline_parent); + if (err) { + pr_err("Failed to register parent device!\n"); + return err; + } + vm_cmdline_parent_registered = 1; + } + + pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", + vm_cmdline_id, + (unsigned long long)resources[0].start, + (unsigned long long)resources[0].end, + (int)resources[1].start); + + pdev = platform_device_register_resndata(&vm_cmdline_parent, + "virtio-mmio", vm_cmdline_id++, + resources, ARRAY_SIZE(resources), NULL, 0); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + return 0; +} + +static int vm_cmdline_get_device(struct device *dev, void *data) +{ + char *buffer = data; + unsigned int len = strlen(buffer); + struct platform_device *pdev = to_platform_device(dev); + + snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", + pdev->resource[0].end - pdev->resource[0].start + 1ULL, + (unsigned long long)pdev->resource[0].start, + (unsigned long long)pdev->resource[1].start, + pdev->id); + return 0; +} + +static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) +{ + buffer[0] = '\0'; + device_for_each_child(&vm_cmdline_parent, buffer, + vm_cmdline_get_device); + return strlen(buffer) + 1; +} + +static struct kernel_param_ops vm_cmdline_param_ops = { + .set = vm_cmdline_set, + .get = vm_cmdline_get, +}; + +device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); + +static int vm_unregister_cmdline_device(struct device *dev, + void *data) +{ + platform_device_unregister(to_platform_device(dev)); + + return 0; +} + +static void vm_unregister_cmdline_devices(void) +{ + if (vm_cmdline_parent_registered) { + device_for_each_child(&vm_cmdline_parent, NULL, + vm_unregister_cmdline_device); + device_unregister(&vm_cmdline_parent); + vm_cmdline_parent_registered = 0; + } +} + +#else + +static void vm_unregister_cmdline_devices(void) +{ +} + +#endif + /* Platform driver */ static struct of_device_id virtio_mmio_match[] = { @@ -453,7 +639,7 @@ MODULE_DEVICE_TABLE(of, virtio_mmio_match); static struct platform_driver virtio_mmio_driver = { .probe = virtio_mmio_probe, - .remove = __devexit_p(virtio_mmio_remove), + .remove = virtio_mmio_remove, .driver = { .name = "virtio-mmio", .owner = THIS_MODULE, @@ -469,6 +655,7 @@ static int __init virtio_mmio_init(void) static void __exit virtio_mmio_exit(void) { platform_driver_unregister(&virtio_mmio_driver); + vm_unregister_cmdline_devices(); } module_init(virtio_mmio_init); diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 03d1984bd36..101db3faf5d 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -48,6 +48,7 @@ struct virtio_pci_device int msix_enabled; int intx_enabled; struct msix_entry *msix_entries; + cpumask_var_t *msix_affinity_masks; /* Name strings for interrupts. This size should be enough, * and I'm too lazy to allocate each name separately. */ char (*msix_names)[256]; @@ -55,6 +56,10 @@ 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; }; @@ -75,9 +80,6 @@ struct virtio_pci_vq_info /* the number of entries in the queue */ int num; - /* the index of the queue */ - int queue_index; - /* the virtual address of the ring queue */ void *queue; @@ -89,9 +91,9 @@ struct virtio_pci_vq_info }; /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */ -static struct pci_device_id virtio_pci_id_table[] = { - { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 }, - { 0 }, +static DEFINE_PCI_DEVICE_TABLE(virtio_pci_id_table) = { + { PCI_DEVICE(0x1af4, PCI_ANY_ID) }, + { 0 } }; MODULE_DEVICE_TABLE(pci, virtio_pci_id_table); @@ -195,14 +197,14 @@ static void vp_reset(struct virtio_device *vdev) } /* the notify function used when creating a virt queue */ -static void vp_notify(struct virtqueue *vq) +static bool vp_notify(struct virtqueue *vq) { struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); - struct virtio_pci_vq_info *info = vq->priv; /* we write the queue's selector into the notification register to * signal the other end */ - iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY); + iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY); + return true; } /* Handle a configuration change: Tell driver if it wants to know. */ @@ -275,6 +277,10 @@ static void vp_free_vectors(struct virtio_device *vdev) for (i = 0; i < vp_dev->msix_used_vectors; ++i) free_irq(vp_dev->msix_entries[i].vector, vp_dev); + for (i = 0; i < vp_dev->msix_vectors; i++) + if (vp_dev->msix_affinity_masks[i]) + free_cpumask_var(vp_dev->msix_affinity_masks[i]); + if (vp_dev->msix_enabled) { /* Disable the vector used for configuration */ iowrite16(VIRTIO_MSI_NO_VECTOR, @@ -284,14 +290,16 @@ static void vp_free_vectors(struct virtio_device *vdev) pci_disable_msix(vp_dev->pci_dev); vp_dev->msix_enabled = 0; - vp_dev->msix_vectors = 0; } + vp_dev->msix_vectors = 0; vp_dev->msix_used_vectors = 0; kfree(vp_dev->msix_names); vp_dev->msix_names = NULL; kfree(vp_dev->msix_entries); vp_dev->msix_entries = NULL; + kfree(vp_dev->msix_affinity_masks); + vp_dev->msix_affinity_masks = NULL; } static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, @@ -302,6 +310,8 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, unsigned i, v; int err = -ENOMEM; + vp_dev->msix_vectors = nvectors; + vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries, GFP_KERNEL); if (!vp_dev->msix_entries) @@ -310,17 +320,23 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, GFP_KERNEL); if (!vp_dev->msix_names) goto error; + vp_dev->msix_affinity_masks + = kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks, + GFP_KERNEL); + if (!vp_dev->msix_affinity_masks) + goto error; + for (i = 0; i < nvectors; ++i) + if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i], + GFP_KERNEL)) + goto error; for (i = 0; i < nvectors; ++i) vp_dev->msix_entries[i].entry = i; - /* pci_enable_msix returns positive if we can't get this many. */ - err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors); - if (err > 0) - err = -ENOSPC; + err = pci_enable_msix_exact(vp_dev->pci_dev, + vp_dev->msix_entries, nvectors); if (err) goto error; - vp_dev->msix_vectors = nvectors; vp_dev->msix_enabled = 1; /* Set the vector used for configuration */ @@ -398,7 +414,6 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index, if (!info) return ERR_PTR(-ENOMEM); - info->queue_index = index; info->num = num; info->msix_vector = msix_vec; @@ -414,8 +429,8 @@ 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(index, info->num, VIRTIO_PCI_VRING_ALIGN, vdev, + true, info->queue, vp_notify, callback, name); if (!vq) { err = -ENOMEM; goto out_activate_queue; @@ -463,7 +478,7 @@ static void vp_del_vq(struct virtqueue *vq) list_del(&info->node); spin_unlock_irqrestore(&vp_dev->lock, flags); - iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); + iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); if (vp_dev->msix_enabled) { iowrite16(VIRTIO_MSI_NO_VECTOR, @@ -538,7 +553,10 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs, vp_dev->per_vq_vectors = per_vq_vectors; allocated_vectors = vp_dev->msix_used_vectors; for (i = 0; i < nvqs; ++i) { - if (!callbacks[i] || !vp_dev->msix_enabled) + if (!names[i]) { + vqs[i] = NULL; + continue; + } else if (!callbacks[i] || !vp_dev->msix_enabled) msix_vec = VIRTIO_MSI_NO_VECTOR; else if (vp_dev->per_vq_vectors) msix_vec = allocated_vectors++; @@ -598,7 +616,43 @@ static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs, false, false); } -static struct virtio_config_ops virtio_pci_config_ops = { +static const char *vp_bus_name(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + return pci_name(vp_dev->pci_dev); +} + +/* Setup the affinity for a virtqueue: + * - force the affinity for per vq vector + * - OR over all affinities for shared MSI + * - ignore the affinity request if we're using INTX + */ +static int vp_set_vq_affinity(struct virtqueue *vq, int cpu) +{ + struct virtio_device *vdev = vq->vdev; + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_vq_info *info = vq->priv; + struct cpumask *mask; + unsigned int irq; + + if (!vq->callback) + return -EINVAL; + + if (vp_dev->msix_enabled) { + mask = vp_dev->msix_affinity_masks[info->msix_vector]; + irq = vp_dev->msix_entries[info->msix_vector].vector; + if (cpu == -1) + irq_set_affinity_hint(irq, NULL); + else { + cpumask_set_cpu(cpu, mask); + irq_set_affinity_hint(irq, mask); + } + } + return 0; +} + +static const struct virtio_config_ops virtio_pci_config_ops = { .get = vp_get, .set = vp_set, .get_status = vp_get_status, @@ -608,6 +662,8 @@ static struct virtio_config_ops virtio_pci_config_ops = { .del_vqs = vp_del_vqs, .get_features = vp_get_features, .finalize_features = vp_finalize_features, + .bus_name = vp_bus_name, + .set_vq_affinity = vp_set_vq_affinity, }; static void virtio_pci_release_dev(struct device *_d) @@ -620,8 +676,8 @@ static void virtio_pci_release_dev(struct device *_d) } /* the PCI probing function */ -static int __devinit virtio_pci_probe(struct pci_dev *pci_dev, - const struct pci_device_id *id) +static int virtio_pci_probe(struct pci_dev *pci_dev, + const struct pci_device_id *id) { struct virtio_pci_device *vp_dev; int err; @@ -661,8 +717,10 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev, goto out_enable_device; vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0); - if (vp_dev->ioaddr == NULL) + if (vp_dev->ioaddr == NULL) { + err = -ENOMEM; goto out_req_regions; + } pci_set_drvdata(pci_dev, vp_dev); pci_set_master(pci_dev); @@ -682,7 +740,6 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev, return 0; out_set_drvdata: - pci_set_drvdata(pci_dev, NULL); pci_iounmap(pci_dev, vp_dev->ioaddr); out_req_regions: pci_release_regions(pci_dev); @@ -693,57 +750,80 @@ out: return err; } -static void __devexit virtio_pci_remove(struct pci_dev *pci_dev) +static void virtio_pci_remove(struct pci_dev *pci_dev) { struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); unregister_virtio_device(&vp_dev->vdev); vp_del_vqs(&vp_dev->vdev); - pci_set_drvdata(pci_dev, NULL); pci_iounmap(pci_dev, vp_dev->ioaddr); pci_release_regions(pci_dev); pci_disable_device(pci_dev); kfree(vp_dev); } -#ifdef CONFIG_PM -static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state) +#ifdef CONFIG_PM_SLEEP +static int virtio_pci_freeze(struct device *dev) { - pci_save_state(pci_dev); - pci_set_power_state(pci_dev, PCI_D3hot); - return 0; + 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 virtio_pci_resume(struct pci_dev *pci_dev) +static int virtio_pci_restore(struct device *dev) { - pci_restore_state(pci_dev); - pci_set_power_state(pci_dev, PCI_D0); - return 0; + 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 = pci_enable_device(pci_dev); + if (ret) + return ret; + + pci_set_master(pci_dev); + vp_finalize_features(&vp_dev->vdev); + + 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 const struct dev_pm_ops virtio_pci_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore) +}; #endif static struct pci_driver virtio_pci_driver = { .name = "virtio-pci", .id_table = virtio_pci_id_table, .probe = virtio_pci_probe, - .remove = __devexit_p(virtio_pci_remove), -#ifdef CONFIG_PM - .suspend = virtio_pci_suspend, - .resume = virtio_pci_resume, + .remove = virtio_pci_remove, +#ifdef CONFIG_PM_SLEEP + .driver.pm = &virtio_pci_pm_ops, #endif }; -static int __init virtio_pci_init(void) -{ - return pci_register_driver(&virtio_pci_driver); -} - -module_init(virtio_pci_init); - -static void __exit virtio_pci_exit(void) -{ - pci_unregister_driver(&virtio_pci_driver); -} - -module_exit(virtio_pci_exit); +module_pci_driver(virtio_pci_driver); diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 4a88ac3a6d2..4d08f45a9c2 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -22,24 +22,8 @@ #include <linux/device.h> #include <linux/slab.h> #include <linux/module.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() -#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() -#endif +#include <linux/hrtimer.h> +#include <linux/kmemleak.h> #ifdef DEBUG /* For development, we want to crash whenever the ring is screwed. */ @@ -77,6 +61,9 @@ 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; @@ -86,8 +73,6 @@ struct vring_virtqueue /* Host publishes avail event idx */ bool event; - /* Number of free buffers */ - unsigned int num_free; /* Head of free buffer list. */ unsigned int free_head; /* Number we've added since last sync. */ @@ -97,11 +82,15 @@ struct vring_virtqueue u16 last_used_idx; /* How to notify other side. FIXME: commonalize hcalls! */ - void (*notify)(struct virtqueue *vq); + bool (*notify)(struct virtqueue *vq); #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. */ @@ -110,16 +99,36 @@ struct vring_virtqueue #define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) +static inline struct scatterlist *sg_next_chained(struct scatterlist *sg, + unsigned int *count) +{ + return sg_next(sg); +} + +static inline struct scatterlist *sg_next_arr(struct scatterlist *sg, + unsigned int *count) +{ + if (--(*count) == 0) + return NULL; + return sg + 1; +} + /* 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, - gfp_t gfp) +static inline int vring_add_indirect(struct vring_virtqueue *vq, + struct scatterlist *sgs[], + struct scatterlist *(*next) + (struct scatterlist *, unsigned int *), + unsigned int total_sg, + unsigned int total_out, + unsigned int total_in, + unsigned int out_sgs, + unsigned int in_sgs, + gfp_t gfp) { struct vring_desc *desc; unsigned head; - int i; + struct scatterlist *sg; + int i, n; /* * We require lowmem mappings for the descriptors because @@ -128,37 +137,45 @@ static int vring_add_indirect(struct vring_virtqueue *vq, */ gfp &= ~(__GFP_HIGHMEM | __GFP_HIGH); - desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp); + desc = kmalloc(total_sg * sizeof(struct vring_desc), gfp); if (!desc) return -ENOMEM; - /* 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++; + /* Transfer entries from the sg lists into the indirect page */ + i = 0; + for (n = 0; n < out_sgs; n++) { + for (sg = sgs[n]; sg; sg = next(sg, &total_out)) { + desc[i].flags = VRING_DESC_F_NEXT; + desc[i].addr = sg_phys(sg); + desc[i].len = sg->length; + desc[i].next = i+1; + i++; + } } - 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++; + for (; n < (out_sgs + in_sgs); n++) { + for (sg = sgs[n]; sg; sg = next(sg, &total_in)) { + 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; + i++; + } } + BUG_ON(i != total_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--; + vq->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); + /* kmemleak gives a false positive, as it's hidden by virt_to_phys */ + kmemleak_ignore(desc); vq->vring.desc[head].len = i * sizeof(struct vring_desc); /* Update free pointer */ @@ -167,61 +184,92 @@ 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) +static inline int virtqueue_add(struct virtqueue *_vq, + struct scatterlist *sgs[], + struct scatterlist *(*next) + (struct scatterlist *, unsigned int *), + unsigned int total_out, + unsigned int total_in, + unsigned int out_sgs, + unsigned int in_sgs, + void *data, + gfp_t gfp) { struct vring_virtqueue *vq = to_vvq(_vq); - unsigned int i, avail, uninitialized_var(prev); + struct scatterlist *sg; + unsigned int i, n, avail, uninitialized_var(prev), total_sg; int head; START_USE(vq); BUG_ON(data == NULL); + if (unlikely(vq->broken)) { + END_USE(vq); + return -EIO; + } + +#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 + + total_sg = total_in + total_out; + /* 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, gfp); + if (vq->indirect && total_sg > 1 && vq->vq.num_free) { + head = vring_add_indirect(vq, sgs, next, total_sg, total_out, + total_in, + out_sgs, in_sgs, gfp); if (likely(head >= 0)) goto add_head; } - BUG_ON(out + in > vq->vring.num); - BUG_ON(out + in == 0); + BUG_ON(total_sg > vq->vring.num); + BUG_ON(total_sg == 0); - if (vq->num_free < out + in) { + if (vq->vq.num_free < total_sg) { pr_debug("Can't add buf len %i - avail = %i\n", - out + in, vq->num_free); + total_sg, vq->vq.num_free); /* FIXME: for historical reasons, we force a notify here if * there are outgoing parts to the buffer. Presumably the * host should service the ring ASAP. */ - if (out) + if (out_sgs) vq->notify(&vq->vq); END_USE(vq); return -ENOSPC; } /* We're about to use some buffers from the free list. */ - vq->num_free -= out + in; - - head = vq->free_head; - for (i = vq->free_head; out; i = vq->vring.desc[i].next, out--) { - vq->vring.desc[i].flags = VRING_DESC_F_NEXT; - vq->vring.desc[i].addr = sg_phys(sg); - vq->vring.desc[i].len = sg->length; - prev = i; - sg++; + vq->vq.num_free -= total_sg; + + head = i = vq->free_head; + for (n = 0; n < out_sgs; n++) { + for (sg = sgs[n]; sg; sg = next(sg, &total_out)) { + vq->vring.desc[i].flags = VRING_DESC_F_NEXT; + vq->vring.desc[i].addr = sg_phys(sg); + vq->vring.desc[i].len = sg->length; + prev = i; + i = vq->vring.desc[i].next; + } } - for (; in; i = vq->vring.desc[i].next, in--) { - vq->vring.desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE; - vq->vring.desc[i].addr = sg_phys(sg); - vq->vring.desc[i].len = sg->length; - prev = i; - sg++; + for (; n < (out_sgs + in_sgs); n++) { + for (sg = sgs[n]; sg; sg = next(sg, &total_in)) { + vq->vring.desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE; + vq->vring.desc[i].addr = sg_phys(sg); + vq->vring.desc[i].len = sg->length; + prev = i; + i = vq->vring.desc[i].next; + } } /* Last one doesn't continue. */ vq->vring.desc[prev].flags &= ~VRING_DESC_F_NEXT; @@ -234,40 +282,196 @@ 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->weak_barriers); + 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; + return 0; } -EXPORT_SYMBOL_GPL(virtqueue_add_buf_gfp); -void virtqueue_kick(struct virtqueue *_vq) +/** + * virtqueue_add_sgs - expose buffers to other end + * @vq: the struct virtqueue we're talking about. + * @sgs: array of terminated scatterlists. + * @out_num: the number of scatterlists readable by other side + * @in_num: the number of scatterlists 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 zero or a negative error (ie. ENOSPC, ENOMEM, EIO). + */ +int virtqueue_add_sgs(struct virtqueue *_vq, + struct scatterlist *sgs[], + unsigned int out_sgs, + unsigned int in_sgs, + void *data, + gfp_t gfp) +{ + unsigned int i, total_out, total_in; + + /* Count them first. */ + for (i = total_out = total_in = 0; i < out_sgs; i++) { + struct scatterlist *sg; + for (sg = sgs[i]; sg; sg = sg_next(sg)) + total_out++; + } + for (; i < out_sgs + in_sgs; i++) { + struct scatterlist *sg; + for (sg = sgs[i]; sg; sg = sg_next(sg)) + total_in++; + } + return virtqueue_add(_vq, sgs, sg_next_chained, + total_out, total_in, out_sgs, in_sgs, data, gfp); +} +EXPORT_SYMBOL_GPL(virtqueue_add_sgs); + +/** + * virtqueue_add_outbuf - expose output buffers to other end + * @vq: the struct virtqueue we're talking about. + * @sgs: array of scatterlists (need not be terminated!) + * @num: the number of scatterlists readable by other side + * @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 zero or a negative error (ie. ENOSPC, ENOMEM, EIO). + */ +int virtqueue_add_outbuf(struct virtqueue *vq, + struct scatterlist sg[], unsigned int num, + void *data, + gfp_t gfp) +{ + return virtqueue_add(vq, &sg, sg_next_arr, num, 0, 1, 0, data, gfp); +} +EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); + +/** + * virtqueue_add_inbuf - expose input buffers to other end + * @vq: the struct virtqueue we're talking about. + * @sgs: array of scatterlists (need not be terminated!) + * @num: the number of scatterlists writable by other side + * @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 zero or a negative error (ie. ENOSPC, ENOMEM, EIO). + */ +int virtqueue_add_inbuf(struct virtqueue *vq, + struct scatterlist sg[], unsigned int num, + void *data, + gfp_t gfp) +{ + return virtqueue_add(vq, &sg, sg_next_arr, 0, num, 0, 1, data, gfp); +} +EXPORT_SYMBOL_GPL(virtqueue_add_inbuf); + +/** + * 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->weak_barriers); - 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. + * + * Returns false if host notify failed or queue is broken, otherwise true. + */ +bool virtqueue_notify(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + if (unlikely(vq->broken)) + return false; + + /* Prod other side to tell it about changes. */ + if (!vq->notify(_vq)) { + vq->broken = true; + return false; + } + return true; +} +EXPORT_SYMBOL_GPL(virtqueue_notify); + +/** + * virtqueue_kick - update after add_buf + * @vq: the struct virtqueue + * + * After one or more virtqueue_add_* 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). + * + * Returns false if kick failed, otherwise true. + */ +bool virtqueue_kick(struct virtqueue *vq) +{ + if (virtqueue_kick_prepare(vq)) + return virtqueue_notify(vq); + return true; } EXPORT_SYMBOL_GPL(virtqueue_kick); @@ -287,13 +491,13 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head) while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) { i = vq->vring.desc[i].next; - vq->num_free++; + vq->vq.num_free++; } vq->vring.desc[i].next = vq->free_head; vq->free_head = head; /* Plus final descriptor */ - vq->num_free++; + vq->vq.num_free++; } static inline bool more_used(const struct vring_virtqueue *vq) @@ -301,11 +505,28 @@ 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_*(). + */ 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); @@ -321,10 +542,11 @@ 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->weak_barriers); - 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); @@ -344,14 +566,27 @@ 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->weak_barriers); } +#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); @@ -404,7 +639,7 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx) { struct vring_virtqueue *vq = to_vvq(_vq); - virtio_mb(); + virtio_mb(vq->weak_barriers); return (u16)last_used_idx != vq->vring.used->idx; } EXPORT_SYMBOL_GPL(virtqueue_poll); @@ -427,6 +662,19 @@ 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); @@ -443,7 +691,7 @@ 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->weak_barriers); if (unlikely((u16)(vq->vring.used->idx - vq->last_used_idx) > bufs)) { END_USE(vq); return false; @@ -454,6 +702,14 @@ 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_*(). + * 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); @@ -473,7 +729,7 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq) return buf; } /* That should have freed everything. */ - BUG_ON(vq->num_free != vq->vring.num); + BUG_ON(vq->vq.num_free != vq->vring.num); END_USE(vq); return NULL; @@ -500,11 +756,13 @@ irqreturn_t vring_interrupt(int irq, void *_vq) } EXPORT_SYMBOL_GPL(vring_interrupt); -struct virtqueue *vring_new_virtqueue(unsigned int num, +struct virtqueue *vring_new_virtqueue(unsigned int index, + unsigned int num, unsigned int vring_align, struct virtio_device *vdev, + bool weak_barriers, void *pages, - void (*notify)(struct virtqueue *), + bool (*notify)(struct virtqueue *), void (*callback)(struct virtqueue *), const char *name) { @@ -525,13 +783,17 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, vq->vq.callback = callback; vq->vq.vdev = vdev; vq->vq.name = name; + vq->vq.num_free = num; + vq->vq.index = index; 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); @@ -542,7 +804,6 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; /* Put everything in free lists. */ - vq->num_free = num; vq->free_head = 0; for (i = 0; i < num-1; i++) { vq->vring.desc[i].next = i+1; @@ -580,7 +841,13 @@ 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) { @@ -590,4 +857,27 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *_vq) } EXPORT_SYMBOL_GPL(virtqueue_get_vring_size); +bool virtqueue_is_broken(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + return vq->broken; +} +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"); |