diff options
Diffstat (limited to 'drivers/virtio')
-rw-r--r-- | drivers/virtio/virtio_balloon.c | 109 | ||||
-rw-r--r-- | drivers/virtio/virtio_pci.c | 6 | ||||
-rw-r--r-- | drivers/virtio/virtio_ring.c | 59 |
3 files changed, 157 insertions, 17 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 505be88c82a..369f2eebbad 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -28,7 +28,7 @@ struct virtio_balloon { struct virtio_device *vdev; - struct virtqueue *inflate_vq, *deflate_vq; + struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; /* Where the ballooning thread waits for config to change. */ wait_queue_head_t config_change; @@ -49,6 +49,10 @@ struct virtio_balloon /* The array of pfns we tell the Host about. */ unsigned int num_pfns; u32 pfns[256]; + + /* Memory statistics */ + int need_stats_update; + struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR]; }; static struct virtio_device_id id_table[] = { @@ -154,6 +158,72 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num) } } +static inline void update_stat(struct virtio_balloon *vb, int idx, + u16 tag, u64 val) +{ + BUG_ON(idx >= VIRTIO_BALLOON_S_NR); + vb->stats[idx].tag = tag; + vb->stats[idx].val = val; +} + +#define pages_to_bytes(x) ((u64)(x) << PAGE_SHIFT) + +static void update_balloon_stats(struct virtio_balloon *vb) +{ + unsigned long events[NR_VM_EVENT_ITEMS]; + struct sysinfo i; + int idx = 0; + + all_vm_events(events); + si_meminfo(&i); + + update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN, + pages_to_bytes(events[PSWPIN])); + update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_OUT, + pages_to_bytes(events[PSWPOUT])); + update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]); + update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]); + update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE, + pages_to_bytes(i.freeram)); + update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMTOT, + pages_to_bytes(i.totalram)); +} + +/* + * While most virtqueues communicate guest-initiated requests to the hypervisor, + * the stats queue operates in reverse. The driver initializes the virtqueue + * with a single buffer. From that point forward, all conversations consist of + * a hypervisor request (a call to this function) which directs us to refill + * the virtqueue with a fresh stats buffer. Since stats collection can sleep, + * we notify our kthread which does the actual work via stats_handle_request(). + */ +static void stats_request(struct virtqueue *vq) +{ + struct virtio_balloon *vb; + unsigned int len; + + vb = vq->vq_ops->get_buf(vq, &len); + if (!vb) + return; + vb->need_stats_update = 1; + wake_up(&vb->config_change); +} + +static void stats_handle_request(struct virtio_balloon *vb) +{ + struct virtqueue *vq; + struct scatterlist sg; + + vb->need_stats_update = 0; + update_balloon_stats(vb); + + vq = vb->stats_vq; + sg_init_one(&sg, vb->stats, sizeof(vb->stats)); + if (vq->vq_ops->add_buf(vq, &sg, 1, 0, vb) < 0) + BUG(); + vq->vq_ops->kick(vq); +} + static void virtballoon_changed(struct virtio_device *vdev) { struct virtio_balloon *vb = vdev->priv; @@ -190,8 +260,11 @@ static int balloon(void *_vballoon) try_to_freeze(); wait_event_interruptible(vb->config_change, (diff = towards_target(vb)) != 0 + || vb->need_stats_update || kthread_should_stop() || freezing(current)); + if (vb->need_stats_update) + stats_handle_request(vb); if (diff > 0) fill_balloon(vb, diff); else if (diff < 0) @@ -204,10 +277,10 @@ 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; + 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) { @@ -219,14 +292,31 @@ static int virtballoon_probe(struct virtio_device *vdev) vb->num_pages = 0; init_waitqueue_head(&vb->config_change); vb->vdev = vdev; + vb->need_stats_update = 0; - /* We expect two virtqueues. */ - err = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names); + /* 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); if (err) goto out_free_vb; vb->inflate_vq = vqs[0]; vb->deflate_vq = vqs[1]; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { + struct scatterlist sg; + vb->stats_vq = vqs[2]; + + /* + * Prime this virtqueue with one buffer so the hypervisor can + * use it to signal us later. + */ + sg_init_one(&sg, vb->stats, sizeof vb->stats); + if (vb->stats_vq->vq_ops->add_buf(vb->stats_vq, + &sg, 1, 0, vb) < 0) + BUG(); + vb->stats_vq->vq_ops->kick(vb->stats_vq); + } vb->thread = kthread_run(balloon, vb, "vballoon"); if (IS_ERR(vb->thread)) { @@ -264,7 +354,10 @@ static void __devexit virtballoon_remove(struct virtio_device *vdev) kfree(vb); } -static unsigned int features[] = { VIRTIO_BALLOON_F_MUST_TELL_HOST }; +static unsigned int features[] = { + VIRTIO_BALLOON_F_MUST_TELL_HOST, + VIRTIO_BALLOON_F_STATS_VQ, +}; static struct virtio_driver virtio_balloon_driver = { .feature_table = features, diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 28d9cf7cf72..625447f645d 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -473,7 +473,8 @@ static void vp_del_vqs(struct virtio_device *vdev) list_for_each_entry_safe(vq, n, &vdev->vqs, list) { info = vq->priv; - if (vp_dev->per_vq_vectors) + if (vp_dev->per_vq_vectors && + info->msix_vector != VIRTIO_MSI_NO_VECTOR) free_irq(vp_dev->msix_entries[info->msix_vector].vector, vq); vp_del_vq(vq); @@ -648,6 +649,7 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev, goto out_req_regions; pci_set_drvdata(pci_dev, vp_dev); + pci_set_master(pci_dev); /* we use the subsystem vendor/device id as the virtio vendor/device * id. this allows us to use the same PCI vendor/device id for all @@ -702,7 +704,7 @@ static struct pci_driver virtio_pci_driver = { .name = "virtio-pci", .id_table = virtio_pci_id_table, .probe = virtio_pci_probe, - .remove = virtio_pci_remove, + .remove = __devexit_p(virtio_pci_remove), #ifdef CONFIG_PM .suspend = virtio_pci_suspend, .resume = virtio_pci_resume, diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index fbd2ecde93e..0db906b3c95 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -21,6 +21,24 @@ #include <linux/virtio_config.h> #include <linux/device.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 + #ifdef DEBUG /* For development, we want to crash whenever the ring is screwed. */ #define BAD_RING(_vq, fmt, args...) \ @@ -36,10 +54,9 @@ panic("%s:in_use = %i\n", \ (_vq)->vq.name, (_vq)->in_use); \ (_vq)->in_use = __LINE__; \ - mb(); \ } while (0) #define END_USE(_vq) \ - do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; mb(); } while(0) + do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0) #else #define BAD_RING(_vq, fmt, args...) \ do { \ @@ -221,13 +238,13 @@ static void vring_kick(struct virtqueue *_vq) START_USE(vq); /* Descriptors and available array need to be set before we expose the * new available array entries. */ - wmb(); + virtio_wmb(); vq->vring.avail->idx += vq->num_added; vq->num_added = 0; /* Need to update avail index before checking if we should notify */ - mb(); + virtio_mb(); if (!(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY)) /* Prod other side to tell it about changes. */ @@ -286,7 +303,7 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len) } /* Only get used array entries after they have been exposed by host. */ - rmb(); + virtio_rmb(); 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; @@ -324,7 +341,7 @@ static bool vring_enable_cb(struct virtqueue *_vq) /* We optimistically turn back on interrupts, then check if there was * more to do. */ vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT; - mb(); + virtio_mb(); if (unlikely(more_used(vq))) { END_USE(vq); return false; @@ -334,6 +351,30 @@ static bool vring_enable_cb(struct virtqueue *_vq) return true; } +static void *vring_detach_unused_buf(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + unsigned int i; + void *buf; + + START_USE(vq); + + for (i = 0; i < vq->vring.num; i++) { + if (!vq->data[i]) + continue; + /* detach_buf clears data, so grab it now. */ + buf = vq->data[i]; + detach_buf(vq, i); + END_USE(vq); + return buf; + } + /* That should have freed everything. */ + BUG_ON(vq->num_free != vq->vring.num); + + END_USE(vq); + return NULL; +} + irqreturn_t vring_interrupt(int irq, void *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); @@ -360,6 +401,7 @@ static struct virtqueue_ops vring_vq_ops = { .kick = vring_kick, .disable_cb = vring_disable_cb, .enable_cb = vring_enable_cb, + .detach_unused_buf = vring_detach_unused_buf, }; struct virtqueue *vring_new_virtqueue(unsigned int num, @@ -406,8 +448,11 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, /* Put everything in free lists. */ vq->num_free = num; vq->free_head = 0; - for (i = 0; i < num-1; i++) + for (i = 0; i < num-1; i++) { vq->vring.desc[i].next = i+1; + vq->data[i] = NULL; + } + vq->data[i] = NULL; return &vq->vq; } |