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Commit 62ea1ec5 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost 

Pull virtio fixes from Michael Tsirkin:
 "This includes some fixes and cleanups in virtio and vhost code.

  Most notably, shadowing the index fixes the excessive cacheline
  bouncing observed on AMD platforms"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_ring: shadow available ring flags & index
  virtio: Do not drop __GFP_HIGH in alloc_indirect
  vhost: replace % with & on data path
  tools/virtio: fix byteswap logic
  tools/virtio: move list macro stubs
  virtio: fix memory leak of virtio ida cache layers
  vhost: relax log address alignment
  virtio-net: Stop doing DMA from the stack
parents f41683a2 f277ec42

drivers/net/virtio_net.c

+19 −15
Original line number Diff line number Diff line
@@ -140,6 +140,12 @@ struct virtnet_info { 


	/* CPU hot plug notifier */

	struct notifier_block nb;



	/* Control VQ buffers: protected by the rtnl lock */

	struct virtio_net_ctrl_hdr ctrl_hdr;

	virtio_net_ctrl_ack ctrl_status;

	u8 ctrl_promisc;

	u8 ctrl_allmulti;

};



struct padded_vnet_hdr {
@@ -976,31 +982,30 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 
				 struct scatterlist *out)

{

	struct scatterlist *sgs[4], hdr, stat;

	struct virtio_net_ctrl_hdr ctrl;

	virtio_net_ctrl_ack status = ~0;

	unsigned out_num = 0, tmp;



	/* Caller should know better */

	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));



	ctrl.class = class;

	ctrl.cmd = cmd;

	vi->ctrl_status = ~0;

	vi->ctrl_hdr.class = class;

	vi->ctrl_hdr.cmd = cmd;

	/* Add header */

	sg_init_one(&hdr, &ctrl, sizeof(ctrl));

	sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));

	sgs[out_num++] = &hdr;



	if (out)

		sgs[out_num++] = out;



	/* Add return status. */

	sg_init_one(&stat, &status, sizeof(status));

	sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));

	sgs[out_num] = &stat;



	BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));

	virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);



	if (unlikely(!virtqueue_kick(vi->cvq)))

		return status == VIRTIO_NET_OK;

		return vi->ctrl_status == VIRTIO_NET_OK;



	/* Spin for a response, the kick causes an ioport write, trapping

	 * into the hypervisor, so the request should be handled immediately.
@@ -1009,7 +1014,7 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 
	       !virtqueue_is_broken(vi->cvq))

		cpu_relax();



	return status == VIRTIO_NET_OK;

	return vi->ctrl_status == VIRTIO_NET_OK;

}



static int virtnet_set_mac_address(struct net_device *dev, void *p)
@@ -1151,7 +1156,6 @@ static void virtnet_set_rx_mode(struct net_device *dev) 
{

	struct virtnet_info *vi = netdev_priv(dev);

	struct scatterlist sg[2];

	u8 promisc, allmulti;

	struct virtio_net_ctrl_mac *mac_data;

	struct netdev_hw_addr *ha;

	int uc_count;
@@ -1163,22 +1167,22 @@ static void virtnet_set_rx_mode(struct net_device *dev) 
	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))

		return;



	promisc = ((dev->flags & IFF_PROMISC) != 0);

	allmulti = ((dev->flags & IFF_ALLMULTI) != 0);

	vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);

	vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);



	sg_init_one(sg, &promisc, sizeof(promisc));

	sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));



	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,

				  VIRTIO_NET_CTRL_RX_PROMISC, sg))

		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",

			 promisc ? "en" : "dis");

			 vi->ctrl_promisc ? "en" : "dis");



	sg_init_one(sg, &allmulti, sizeof(allmulti));

	sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));



	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,

				  VIRTIO_NET_CTRL_RX_ALLMULTI, sg))

		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",

			 allmulti ? "en" : "dis");

			 vi->ctrl_allmulti ? "en" : "dis");



	uc_count = netdev_uc_count(dev);

	mc_count = netdev_mc_count(dev);

drivers/vhost/vhost.c

+4 −4
Original line number Diff line number Diff line
@@ -819,7 +819,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) 
		BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE);

		if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) ||

		    (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) ||

		    (a.log_guest_addr & (sizeof(u64) - 1))) {

		    (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) {

			r = -EINVAL;

			break;

		}
@@ -1369,7 +1369,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
	/* Grab the next descriptor number they're advertising, and increment

	 * the index we've seen. */

	if (unlikely(__get_user(ring_head,

				&vq->avail->ring[last_avail_idx % vq->num]))) {

				&vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {

		vq_err(vq, "Failed to read head: idx %d address %p\n",

		       last_avail_idx,

		       &vq->avail->ring[last_avail_idx % vq->num]);
@@ -1489,7 +1489,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq, 
	u16 old, new;

	int start;



	start = vq->last_used_idx % vq->num;

	start = vq->last_used_idx & (vq->num - 1);

	used = vq->used->ring + start;

	if (count == 1) {

		if (__put_user(heads[0].id, &used->id)) {
@@ -1531,7 +1531,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, 
{

	int start, n, r;



	start = vq->last_used_idx % vq->num;

	start = vq->last_used_idx & (vq->num - 1);

	n = vq->num - start;

	if (n < count) {

		r = __vhost_add_used_n(vq, heads, n);

drivers/virtio/virtio.c

+1 −0
Original line number Diff line number Diff line
@@ -412,6 +412,7 @@ static int virtio_init(void) 
static void __exit virtio_exit(void)

{

	bus_unregister(&virtio_bus);

	ida_destroy(&virtio_index_ida);

}

core_initcall(virtio_init);

module_exit(virtio_exit);

drivers/virtio/virtio_ring.c

+35 −13
Original line number Diff line number Diff line
@@ -80,6 +80,12 @@ struct vring_virtqueue { 
	/* Last used index we've seen. */

	u16 last_used_idx;



	/* Last written value to avail->flags */

	u16 avail_flags_shadow;



	/* Last written value to avail->idx in guest byte order */

	u16 avail_idx_shadow;



	/* How to notify other side. FIXME: commonalize hcalls! */

	bool (*notify)(struct virtqueue *vq);
@@ -109,7 +115,7 @@ static struct vring_desc *alloc_indirect(struct virtqueue *_vq, 
	 * otherwise virt_to_phys will give us bogus addresses in the

	 * virtqueue.

	 */

	gfp &= ~(__GFP_HIGHMEM | __GFP_HIGH);

	gfp &= ~__GFP_HIGHMEM;



	desc = kmalloc(total_sg * sizeof(struct vring_desc), gfp);

	if (!desc)
@@ -235,13 +241,14 @@ static inline int virtqueue_add(struct virtqueue *_vq, 


	/* Put entry in available array (but don't update avail->idx until they

	 * do sync). */

	avail = virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) & (vq->vring.num - 1);

	avail = vq->avail_idx_shadow & (vq->vring.num - 1);

	vq->vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, 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 = cpu_to_virtio16(_vq->vdev, virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) + 1);

	vq->avail_idx_shadow++;

	vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);

	vq->num_added++;



	pr_debug("Added buffer head %i to %p\n", head, vq);
@@ -354,8 +361,8 @@ bool virtqueue_kick_prepare(struct virtqueue *_vq) 
	 * event. */

	virtio_mb(vq->weak_barriers);



	old = virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) - vq->num_added;

	new = virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx);

	old = vq->avail_idx_shadow - vq->num_added;

	new = vq->avail_idx_shadow;

	vq->num_added = 0;



#ifdef DEBUG
@@ -510,7 +517,7 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) 
	/* If we expect an interrupt for the next entry, tell host

	 * by writing event index and flush out the write before

	 * the read in the next get_buf call. */

	if (!(vq->vring.avail->flags & cpu_to_virtio16(_vq->vdev, VRING_AVAIL_F_NO_INTERRUPT))) {

	if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {

		vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, vq->last_used_idx);

		virtio_mb(vq->weak_barriers);

	}
@@ -537,7 +544,11 @@ void virtqueue_disable_cb(struct virtqueue *_vq) 
{

	struct vring_virtqueue *vq = to_vvq(_vq);



	vq->vring.avail->flags |= cpu_to_virtio16(_vq->vdev, VRING_AVAIL_F_NO_INTERRUPT);

	if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {

		vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;

		vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);

	}



}

EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
@@ -565,7 +576,10 @@ unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq) 
	/* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to

	 * either clear the flags bit or point the event index at the next

	 * entry. Always do both to keep code simple. */

	vq->vring.avail->flags &= cpu_to_virtio16(_vq->vdev, ~VRING_AVAIL_F_NO_INTERRUPT);

	if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {

		vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;

		vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);

	}

	vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);

	END_USE(vq);

	return last_used_idx;
@@ -633,9 +647,12 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq) 
	/* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to

	 * either clear the flags bit or point the event index at the next

	 * entry. Always do both to keep code simple. */

	vq->vring.avail->flags &= cpu_to_virtio16(_vq->vdev, ~VRING_AVAIL_F_NO_INTERRUPT);

	if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {

		vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;

		vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);

	}

	/* TODO: tune this threshold */

	bufs = (u16)(virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) - vq->last_used_idx) * 3 / 4;

	bufs = (u16)(vq->avail_idx_shadow - vq->last_used_idx) * 3 / 4;

	vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs);

	virtio_mb(vq->weak_barriers);

	if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->vring.used->idx) - vq->last_used_idx) > bufs)) {
@@ -670,7 +687,8 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq) 
		/* detach_buf clears data, so grab it now. */

		buf = vq->data[i];

		detach_buf(vq, i);

		vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, virtio16_to_cpu(_vq->vdev, vq->vring.avail->idx) - 1);

		vq->avail_idx_shadow--;

		vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);

		END_USE(vq);

		return buf;

	}
@@ -735,6 +753,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int index, 
	vq->weak_barriers = weak_barriers;

	vq->broken = false;

	vq->last_used_idx = 0;

	vq->avail_flags_shadow = 0;

	vq->avail_idx_shadow = 0;

	vq->num_added = 0;

	list_add_tail(&vq->vq.list, &vdev->vqs);

#ifdef DEBUG
@@ -746,8 +766,10 @@ struct virtqueue *vring_new_virtqueue(unsigned int index, 
	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);



	/* No callback?  Tell other side not to bother us. */

	if (!callback)

		vq->vring.avail->flags |= cpu_to_virtio16(vdev, VRING_AVAIL_F_NO_INTERRUPT);

	if (!callback) {

		vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;

		vq->vring.avail->flags = cpu_to_virtio16(vdev, vq->avail_flags_shadow);

	}



	/* Put everything in free lists. */

	vq->free_head = 0;

tools/virtio/linux/kernel.h

+6 −0
Original line number Diff line number Diff line
@@ -110,4 +110,10 @@ static inline void free_page(unsigned long addr) 
	(void) (&_min1 == &_min2);		\

	_min1 < _min2 ? _min1 : _min2; })



/* TODO: empty stubs for now. Broken but enough for virtio_ring.c */

#define list_add_tail(a, b) do {} while (0)

#define list_del(a) do {} while (0)

#define list_for_each_entry(a, b, c) while (0)

/* end of stubs */



#endif /* KERNEL_H */