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Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

Browse source 
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (25 commits)
  virtio: balloon driver
  virtio: Use PCI revision field to indicate virtio PCI ABI version
  virtio: PCI device
  virtio_blk: implement naming for vda-vdz,vdaa-vdzz,vdaaa-vdzzz
  virtio_blk: Dont waste major numbers
  virtio_blk: provide getgeo
  virtio_net: parametrize the napi_weight for virtio receive queue.
  virtio: free transmit skbs when notified, not on next xmit.
  virtio: flush buffers on open
  virtnet: remove double ether_setup
  virtio: Allow virtio to be modular and used by modules
  virtio: Use the sg_phys convenience function.
  virtio: Put the virtio under the virtualization menu
  virtio: handle interrupts after callbacks turned off
  virtio: reset function
  virtio: populate network rings in the probe routine, not open
  virtio: Tweak virtio_net defines
  virtio: Net header needs hdr_len
  virtio: remove unused id field from struct virtio_blk_outhdr
  virtio: clarify NO_NOTIFY flag usage
  ...
This commit is contained in:
Linus Torvalds 2008-02-04 08:00:54 -08:00
commit 93890b71a3
26 changed files with 1422 additions and 421 deletions
Download patch file Download diff file Expand all files Collapse all files

2
drivers/Kconfig
View file

@ -91,6 +91,4 @@ source "drivers/dca/Kconfig"
source "drivers/auxdisplay/Kconfig"
source "drivers/uio/Kconfig"
source "drivers/virtio/Kconfig"
endmenu

3
drivers/block/Kconfig
View file

@ -440,6 +440,7 @@ config VIRTIO_BLK
tristate "Virtio block driver (EXPERIMENTAL)"
depends on EXPERIMENTAL && VIRTIO
---help---
This is the virtual block driver for lguest. Say Y or M.
This is the virtual block driver for virtio. It can be used with
lguest or QEMU based VMMs (like KVM or Xen). Say Y or M.
endif # BLK_DEV

106
drivers/block/virtio_blk.c
View file

@ -7,8 +7,10 @@
#include <linux/scatterlist.h>
#define VIRTIO_MAX_SG (3+MAX_PHYS_SEGMENTS)
#define PART_BITS 4
static int major, index;
static unsigned char virtblk_index = 'a';
struct virtio_blk
{
spinlock_t lock;
@ -36,7 +38,7 @@ struct virtblk_req
struct virtio_blk_inhdr in_hdr;
};
static bool blk_done(struct virtqueue *vq)
static void blk_done(struct virtqueue *vq)
{
struct virtio_blk *vblk = vq->vdev->priv;
struct virtblk_req *vbr;
@ -65,7 +67,6 @@ static bool blk_done(struct virtqueue *vq)
/* In case queue is stopped waiting for more buffers. */
blk_start_queue(vblk->disk->queue);
spin_unlock_irqrestore(&vblk->lock, flags);
return true;
}
static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
@ -153,20 +154,37 @@ static int virtblk_ioctl(struct inode *inode, struct file *filp,
(void __user *)data);
}
/* We provide getgeo only to please some old bootloader/partitioning tools */
static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
{
/* some standard values, similar to sd */
geo->heads = 1 << 6;
geo->sectors = 1 << 5;
geo->cylinders = get_capacity(bd->bd_disk) >> 11;
return 0;
}
static struct block_device_operations virtblk_fops = {
.ioctl = virtblk_ioctl,
.owner = THIS_MODULE,
.ioctl = virtblk_ioctl,
.owner = THIS_MODULE,
.getgeo = virtblk_getgeo,
};
static int index_to_minor(int index)
{
return index << PART_BITS;
}
static int virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
int err, major;
void *token;
unsigned int len;
int err;
u64 cap;
u32 v;
if (index_to_minor(index) >= 1 << MINORBITS)
return -ENOSPC;
vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
if (!vblk) {
err = -ENOMEM;
@ -178,7 +196,7 @@ static int virtblk_probe(struct virtio_device *vdev)
vblk->vdev = vdev;
/* We expect one virtqueue, for output. */
vblk->vq = vdev->config->find_vq(vdev, blk_done);
vblk->vq = vdev->config->find_vq(vdev, 0, blk_done);
if (IS_ERR(vblk->vq)) {
err = PTR_ERR(vblk->vq);
goto out_free_vblk;
@ -190,17 +208,11 @@ static int virtblk_probe(struct virtio_device *vdev)
goto out_free_vq;
}
major = register_blkdev(0, "virtblk");
if (major < 0) {
err = major;
goto out_mempool;
}
/* FIXME: How many partitions? How long is a piece of string? */
vblk->disk = alloc_disk(1 << 4);
vblk->disk = alloc_disk(1 << PART_BITS);
if (!vblk->disk) {
err = -ENOMEM;
goto out_unregister_blkdev;
goto out_mempool;
}
vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);
@ -209,22 +221,32 @@ static int virtblk_probe(struct virtio_device *vdev)
goto out_put_disk;
}
sprintf(vblk->disk->disk_name, "vd%c", virtblk_index++);
if (index < 26) {
sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
} else if (index < (26 + 1) * 26) {
sprintf(vblk->disk->disk_name, "vd%c%c",
'a' + index / 26 - 1, 'a' + index % 26);
} else {
const unsigned int m1 = (index / 26 - 1) / 26 - 1;
const unsigned int m2 = (index / 26 - 1) % 26;
const unsigned int m3 = index % 26;
sprintf(vblk->disk->disk_name, "vd%c%c%c",
'a' + m1, 'a' + m2, 'a' + m3);
}
vblk->disk->major = major;
vblk->disk->first_minor = 0;
vblk->disk->first_minor = index_to_minor(index);
vblk->disk->private_data = vblk;
vblk->disk->fops = &virtblk_fops;
index++;
/* If barriers are supported, tell block layer that queue is ordered */
token = vdev->config->find(vdev, VIRTIO_CONFIG_BLK_F, &len);
if (virtio_use_bit(vdev, token, len, VIRTIO_BLK_F_BARRIER))
if (vdev->config->feature(vdev, VIRTIO_BLK_F_BARRIER))
blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);
err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_CAPACITY, &cap);
if (err) {
dev_err(&vdev->dev, "Bad/missing capacity in config\n");
goto out_cleanup_queue;
}
/* Host must always specify the capacity. */
__virtio_config_val(vdev, offsetof(struct virtio_blk_config, capacity),
&cap);
/* If capacity is too big, truncate with warning. */
if ((sector_t)cap != cap) {
@ -234,31 +256,25 @@ static int virtblk_probe(struct virtio_device *vdev)
}
set_capacity(vblk->disk, cap);
err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SIZE_MAX, &v);
/* Host can optionally specify maximum segment size and number of
* segments. */
err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
offsetof(struct virtio_blk_config, size_max),
&v);
if (!err)
blk_queue_max_segment_size(vblk->disk->queue, v);
else if (err != -ENOENT) {
dev_err(&vdev->dev, "Bad SIZE_MAX in config\n");
goto out_cleanup_queue;
}
err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SEG_MAX, &v);
err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
offsetof(struct virtio_blk_config, seg_max),
&v);
if (!err)
blk_queue_max_hw_segments(vblk->disk->queue, v);
else if (err != -ENOENT) {
dev_err(&vdev->dev, "Bad SEG_MAX in config\n");
goto out_cleanup_queue;
}
add_disk(vblk->disk);
return 0;
out_cleanup_queue:
blk_cleanup_queue(vblk->disk->queue);
out_put_disk:
put_disk(vblk->disk);
out_unregister_blkdev:
unregister_blkdev(major, "virtblk");
out_mempool:
mempool_destroy(vblk->pool);
out_free_vq:
@ -274,12 +290,16 @@ static void virtblk_remove(struct virtio_device *vdev)
struct virtio_blk *vblk = vdev->priv;
int major = vblk->disk->major;
/* Nothing should be pending. */
BUG_ON(!list_empty(&vblk->reqs));
/* Stop all the virtqueues. */
vdev->config->reset(vdev);
blk_cleanup_queue(vblk->disk->queue);
put_disk(vblk->disk);
unregister_blkdev(major, "virtblk");
mempool_destroy(vblk->pool);
/* There should be nothing in the queue now, so no need to shutdown */
vdev->config->del_vq(vblk->vq);
kfree(vblk);
}
@ -299,11 +319,15 @@ static struct virtio_driver virtio_blk = {
static int __init init(void)
{
major = register_blkdev(0, "virtblk");
if (major < 0)
return major;
return register_virtio_driver(&virtio_blk);
}
static void __exit fini(void)
{
unregister_blkdev(major, "virtblk");
unregister_virtio_driver(&virtio_blk);
}
module_init(init);

4
drivers/char/virtio_console.c
View file

@ -158,13 +158,13 @@ static int __devinit virtcons_probe(struct virtio_device *dev)
/* Find the input queue. */
/* FIXME: This is why we want to wean off hvc: we do nothing
* when input comes in. */
in_vq = vdev->config->find_vq(vdev, NULL);
in_vq = vdev->config->find_vq(vdev, 0, NULL);
if (IS_ERR(in_vq)) {
err = PTR_ERR(in_vq);
goto free;
}
out_vq = vdev->config->find_vq(vdev, NULL);
out_vq = vdev->config->find_vq(vdev, 1, NULL);
if (IS_ERR(out_vq)) {
err = PTR_ERR(out_vq);
goto free_in_vq;

142
drivers/lguest/lguest_device.c
View file

@ -52,57 +52,82 @@ struct lguest_device {
/*D:130
* Device configurations
*
* The configuration information for a device consists of a series of fields.
* We don't really care what they are: the Launcher set them up, and the driver
* will look at them during setup.
* The configuration information for a device consists of one or more
* virtqueues, a feature bitmaks, and some configuration bytes. The
* configuration bytes don't really matter to us: the Launcher sets them up, and
* the driver will look at them during setup.
*
* For us these fields come immediately after that device's descriptor in the
* lguest_devices page.
*
* Each field starts with a "type" byte, a "length" byte, then that number of
* bytes of configuration information. The device descriptor tells us the
* total configuration length so we know when we've reached the last field. */
* A convenient routine to return the device's virtqueue config array:
* immediately after the descriptor. */
static struct lguest_vqconfig *lg_vq(const struct lguest_device_desc *desc)
{
return (void *)(desc + 1);
}
/* type + length bytes */
#define FHDR_LEN 2
/* The features come immediately after the virtqueues. */
static u8 *lg_features(const struct lguest_device_desc *desc)
{
return (void *)(lg_vq(desc) + desc->num_vq);
}
/* This finds the first field of a given type for a device's configuration. */
static void *lg_find(struct virtio_device *vdev, u8 type, unsigned int *len)
/* The config space comes after the two feature bitmasks. */
static u8 *lg_config(const struct lguest_device_desc *desc)
{
return lg_features(desc) + desc->feature_len * 2;
}
/* The total size of the config page used by this device (incl. desc) */
static unsigned desc_size(const struct lguest_device_desc *desc)
{
return sizeof(*desc)
+ desc->num_vq * sizeof(struct lguest_vqconfig)
+ desc->feature_len * 2
+ desc->config_len;
}
/* This tests (and acknowleges) a feature bit. */
static bool lg_feature(struct virtio_device *vdev, unsigned fbit)
{
struct lguest_device_desc *desc = to_lgdev(vdev)->desc;
int i;
u8 *features;
for (i = 0; i < desc->config_len; i += FHDR_LEN + desc->config[i+1]) {
if (desc->config[i] == type) {
/* Mark it used, so Host can know we looked at it, and
* also so we won't find the same one twice. */
desc->config[i] |= 0x80;
/* Remember, the second byte is the length. */
*len = desc->config[i+1];
/* We return a pointer to the field header. */
return desc->config + i;
}
}
/* Obviously if they ask for a feature off the end of our feature
* bitmap, it's not set. */
if (fbit / 8 > desc->feature_len)
return false;
/* Not found: return NULL for failure. */
return NULL;
/* The feature bitmap comes after the virtqueues. */
features = lg_features(desc);
if (!(features[fbit / 8] & (1 << (fbit % 8))))
return false;
/* We set the matching bit in the other half of the bitmap to tell the
* Host we want to use this feature. We don't use this yet, but we
* could in future. */
features[desc->feature_len + fbit / 8] |= (1 << (fbit % 8));
return true;
}
/* Once they've found a field, getting a copy of it is easy. */
static void lg_get(struct virtio_device *vdev, void *token,
static void lg_get(struct virtio_device *vdev, unsigned int offset,
void *buf, unsigned len)
{
/* Check they didn't ask for more than the length of the field! */
BUG_ON(len > ((u8 *)token)[1]);
memcpy(buf, token + FHDR_LEN, len);
struct lguest_device_desc *desc = to_lgdev(vdev)->desc;
/* Check they didn't ask for more than the length of the config! */
BUG_ON(offset + len > desc->config_len);
memcpy(buf, lg_config(desc) + offset, len);
}
/* Setting the contents is also trivial. */
static void lg_set(struct virtio_device *vdev, void *token,
static void lg_set(struct virtio_device *vdev, unsigned int offset,
const void *buf, unsigned len)
{
BUG_ON(len > ((u8 *)token)[1]);
memcpy(token + FHDR_LEN, buf, len);
struct lguest_device_desc *desc = to_lgdev(vdev)->desc;
/* Check they didn't ask for more than the length of the config! */
BUG_ON(offset + len > desc->config_len);
memcpy(lg_config(desc) + offset, buf, len);
}
/* The operations to get and set the status word just access the status field
@ -114,9 +139,20 @@ static u8 lg_get_status(struct virtio_device *vdev)
static void lg_set_status(struct virtio_device *vdev, u8 status)
{
BUG_ON(!status);
to_lgdev(vdev)->desc->status = status;
}
/* To reset the device, we (ab)use the NOTIFY hypercall, with the descriptor
* address of the device. The Host will zero the status and all the
* features. */
static void lg_reset(struct virtio_device *vdev)
{
unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices;
hcall(LHCALL_NOTIFY, (max_pfn<<PAGE_SHIFT) + offset, 0, 0);
}
/*
* Virtqueues
*
@ -165,39 +201,29 @@ static void lg_notify(struct virtqueue *vq)
*
* So we provide devices with a "find virtqueue and set it up" function. */
static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
bool (*callback)(struct virtqueue *vq))
unsigned index,
void (*callback)(struct virtqueue *vq))
{
struct lguest_device *ldev = to_lgdev(vdev);
struct lguest_vq_info *lvq;
struct virtqueue *vq;
unsigned int len;
void *token;
int err;
/* Look for a field of the correct type to mark a virtqueue. Note that
* if this succeeds, then the type will be changed so it won't be found
* again, and future lg_find_vq() calls will find the next
* virtqueue (if any). */
token = vdev->config->find(vdev, VIRTIO_CONFIG_F_VIRTQUEUE, &len);
if (!token)
/* We must have this many virtqueues. */
if (index >= ldev->desc->num_vq)
return ERR_PTR(-ENOENT);
lvq = kmalloc(sizeof(*lvq), GFP_KERNEL);
if (!lvq)
return ERR_PTR(-ENOMEM);
/* Note: we could use a configuration space inside here, just like we
* do for the device. This would allow expansion in future, because
* our configuration system is designed to be expansible. But this is
* way easier. */
if (len != sizeof(lvq->config)) {
dev_err(&vdev->dev, "Unexpected virtio config len %u\n", len);
err = -EIO;
goto free_lvq;
}
/* Make a copy of the "struct lguest_vqconfig" field. We need a copy
* because the config space might not be aligned correctly. */
vdev->config->get(vdev, token, &lvq->config, sizeof(lvq->config));
/* Make a copy of the "struct lguest_vqconfig" entry, which sits after
* the descriptor. We need a copy because the config space might not
* be aligned correctly. */
memcpy(&lvq->config, lg_vq(ldev->desc)+index, sizeof(lvq->config));
printk("Mapping virtqueue %i addr %lx\n", index,
(unsigned long)lvq->config.pfn << PAGE_SHIFT);
/* Figure out how many pages the ring will take, and map that memory */
lvq->pages = lguest_map((unsigned long)lvq->config.pfn << PAGE_SHIFT,
DIV_ROUND_UP(vring_size(lvq->config.num,
@ -259,11 +285,12 @@ static void lg_del_vq(struct virtqueue *vq)
/* The ops structure which hooks everything together. */
static struct virtio_config_ops lguest_config_ops = {
.find = lg_find,
.feature = lg_feature,
.get = lg_get,
.set = lg_set,
.get_status = lg_get_status,
.set_status = lg_set_status,
.reset = lg_reset,
.find_vq = lg_find_vq,
.del_vq = lg_del_vq,
};
@ -329,13 +356,14 @@ static void scan_devices(void)
struct lguest_device_desc *d;
/* We start at the page beginning, and skip over each entry. */
for (i = 0; i < PAGE_SIZE; i += sizeof(*d) + d->config_len) {
for (i = 0; i < PAGE_SIZE; i += desc_size(d)) {
d = lguest_devices + i;
/* Once we hit a zero, stop. */
if (d->type == 0)
break;
printk("Device at %i has size %u\n", i, desc_size(d));
add_lguest_device(d);
}
}

3
drivers/net/Kconfig
View file

@ -3114,6 +3114,7 @@ config VIRTIO_NET
tristate "Virtio network driver (EXPERIMENTAL)"
depends on EXPERIMENTAL && VIRTIO
---help---
This is the virtual network driver for lguest. Say Y or M.
This is the virtual network driver for virtio. It can be used with
lguest or QEMU based VMMs (like KVM or Xen). Say Y or M.
endif # NETDEVICES

157
drivers/net/virtio_net.c
View file

@ -24,6 +24,13 @@
#include <linux/virtio_net.h>
#include <linux/scatterlist.h>
static int napi_weight = 128;
module_param(napi_weight, int, 0444);
static int csum = 1, gso = 1;
module_param(csum, bool, 0444);
module_param(gso, bool, 0444);
/* FIXME: MTU in config. */
#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
@ -52,13 +59,14 @@ static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
}
static bool skb_xmit_done(struct virtqueue *rvq)
static void skb_xmit_done(struct virtqueue *svq)
{
struct virtnet_info *vi = rvq->vdev->priv;
struct virtnet_info *vi = svq->vdev->priv;
/* In case we were waiting for output buffers. */
/* Suppress further interrupts. */
svq->vq_ops->disable_cb(svq);
/* We were waiting for more output buffers. */
netif_wake_queue(vi->dev);
return true;
}
static void receive_skb(struct net_device *dev, struct sk_buff *skb,
@ -83,28 +91,16 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
pr_debug("Needs csum!\n");
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = hdr->csum_start;
skb->csum_offset = hdr->csum_offset;
if (skb->csum_start > skb->len - 2
|| skb->csum_offset > skb->len - 2) {
if (net_ratelimit())
printk(KERN_WARNING "%s: csum=%u/%u len=%u\n",
dev->name, skb->csum_start,
skb->csum_offset, skb->len);
if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
goto frame_err;
}
}
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
pr_debug("GSO!\n");
switch (hdr->gso_type) {
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
break;
case VIRTIO_NET_HDR_GSO_TCPV4_ECN:
skb_shinfo(skb)->gso_type = SKB_GSO_TCP_ECN;
break;
case VIRTIO_NET_HDR_GSO_UDP:
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
break;
@ -118,6 +114,9 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
goto frame_err;
}
if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
skb_shinfo(skb)->gso_size = hdr->gso_size;
if (skb_shinfo(skb)->gso_size == 0) {
if (net_ratelimit())
@ -170,12 +169,14 @@ static void try_fill_recv(struct virtnet_info *vi)
vi->rvq->vq_ops->kick(vi->rvq);
}
static bool skb_recv_done(struct virtqueue *rvq)
static void skb_recv_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
netif_rx_schedule(vi->dev, &vi->napi);
/* Suppress further interrupts. */
return false;
/* Schedule NAPI, Suppress further interrupts if successful. */
if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
rvq->vq_ops->disable_cb(rvq);
__netif_rx_schedule(vi->dev, &vi->napi);
}
}
static int virtnet_poll(struct napi_struct *napi, int budget)
@ -201,7 +202,7 @@ again:
/* Out of packets? */
if (received < budget) {
netif_rx_complete(vi->dev, napi);
if (unlikely(!vi->rvq->vq_ops->restart(vi->rvq))
if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
&& netif_rx_reschedule(vi->dev, napi))
goto again;
}
@ -236,8 +237,6 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev)
pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));
free_old_xmit_skbs(vi);
/* Encode metadata header at front. */
hdr = skb_vnet_hdr(skb);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
@ -250,10 +249,9 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev)
}
if (skb_is_gso(skb)) {
hdr->hdr_len = skb_transport_header(skb) - skb->data;
hdr->gso_size = skb_shinfo(skb)->gso_size;
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4_ECN;
else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
@ -261,19 +259,34 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev)
hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
else
BUG();
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else {
hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
hdr->gso_size = 0;
hdr->gso_size = hdr->hdr_len = 0;
}
vnet_hdr_to_sg(sg, skb);
num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
__skb_queue_head(&vi->send, skb);
again:
/* Free up any pending old buffers before queueing new ones. */
free_old_xmit_skbs(vi);
err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
if (err) {
pr_debug("%s: virtio not prepared to send\n", dev->name);
skb_unlink(skb, &vi->send);
netif_stop_queue(dev);
/* Activate callback for using skbs: if this fails it
* means some were used in the meantime. */
if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
printk("Unlikely: restart svq failed\n");
netif_start_queue(dev);
goto again;
}
__skb_unlink(skb, &vi->send);
return NETDEV_TX_BUSY;
}
vi->svq->vq_ops->kick(vi->svq);
@ -285,45 +298,31 @@ static int virtnet_open(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
try_fill_recv(vi);
/* If we didn't even get one input buffer, we're useless. */
if (vi->num == 0)
return -ENOMEM;
napi_enable(&vi->napi);
/* If all buffers were filled by other side before we napi_enabled, we
* won't get another interrupt, so process any outstanding packets
* now. virtnet_poll wants re-enable the queue, so we disable here. */
vi->rvq->vq_ops->disable_cb(vi->rvq);
netif_rx_schedule(vi->dev, &vi->napi);
return 0;
}
static int virtnet_close(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
struct sk_buff *skb;
napi_disable(&vi->napi);
/* networking core has neutered skb_xmit_done/skb_recv_done, so don't
* worry about races vs. get(). */
vi->rvq->vq_ops->shutdown(vi->rvq);
while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
kfree_skb(skb);
vi->num--;
}
vi->svq->vq_ops->shutdown(vi->svq);
while ((skb = __skb_dequeue(&vi->send)) != NULL)
kfree_skb(skb);
BUG_ON(vi->num != 0);
return 0;
}
static int virtnet_probe(struct virtio_device *vdev)
{
int err;
unsigned int len;
struct net_device *dev;
struct virtnet_info *vi;
void *token;
/* Allocate ourselves a network device with room for our info */
dev = alloc_etherdev(sizeof(struct virtnet_info));
@ -331,7 +330,6 @@ static int virtnet_probe(struct virtio_device *vdev)
return -ENOMEM;
/* Set up network device as normal. */
ether_setup(dev);
dev->open = virtnet_open;
dev->stop = virtnet_close;
dev->hard_start_xmit = start_xmit;
@ -339,42 +337,37 @@ static int virtnet_probe(struct virtio_device *vdev)
SET_NETDEV_DEV(dev, &vdev->dev);
/* Do we support "hardware" checksums? */
token = vdev->config->find(vdev, VIRTIO_CONFIG_NET_F, &len);
if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_NO_CSUM)) {
if (csum && vdev->config->feature(vdev, VIRTIO_NET_F_CSUM)) {
/* This opens up the world of extra features. */
dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO4))
dev->features |= NETIF_F_TSO;
if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_UFO))
dev->features |= NETIF_F_UFO;
if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO4_ECN))
dev->features |= NETIF_F_TSO_ECN;
if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO6))
dev->features |= NETIF_F_TSO6;
if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_GSO)) {
dev->features |= NETIF_F_TSO | NETIF_F_UFO
| NETIF_F_TSO_ECN | NETIF_F_TSO6;
}
}
/* Configuration may specify what MAC to use. Otherwise random. */
token = vdev->config->find(vdev, VIRTIO_CONFIG_NET_MAC_F, &len);
if (token) {
dev->addr_len = len;
vdev->config->get(vdev, token, dev->dev_addr, len);
if (vdev->config->feature(vdev, VIRTIO_NET_F_MAC)) {
vdev->config->get(vdev,
offsetof(struct virtio_net_config, mac),
dev->dev_addr, dev->addr_len);
} else
random_ether_addr(dev->dev_addr);
/* Set up our device-specific information */
vi = netdev_priv(dev);
netif_napi_add(dev, &vi->napi, virtnet_poll, 16);
netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
vi->dev = dev;
vi->vdev = vdev;
/* We expect two virtqueues, receive then send. */
vi->rvq = vdev->config->find_vq(vdev, skb_recv_done);
vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
if (IS_ERR(vi->rvq)) {
err = PTR_ERR(vi->rvq);
goto free;
}
vi->svq = vdev->config->find_vq(vdev, skb_xmit_done);
vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
if (IS_ERR(vi->svq)) {
err = PTR_ERR(vi->svq);
goto free_recv;
@ -389,10 +382,22 @@ static int virtnet_probe(struct virtio_device *vdev)
pr_debug("virtio_net: registering device failed\n");
goto free_send;
}
/* Last of all, set up some receive buffers. */
try_fill_recv(vi);
/* If we didn't even get one input buffer, we're useless. */
if (vi->num == 0) {
err = -ENOMEM;
goto unregister;
}
pr_debug("virtnet: registered device %s\n", dev->name);
vdev->priv = vi;
return 0;
unregister:
unregister_netdev(dev);
free_send:
vdev->config->del_vq(vi->svq);
free_recv:
@ -405,6 +410,20 @@ free:
static void virtnet_remove(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
struct sk_buff *skb;
/* Stop all the virtqueues. */
vdev->config->reset(vdev);
/* Free our skbs in send and recv queues, if any. */
while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
kfree_skb(skb);
vi->num--;
}
while ((skb = __skb_dequeue(&vi->send)) != NULL)
kfree_skb(skb);
BUG_ON(vi->num != 0);
vdev->config->del_vq(vi->svq);
vdev->config->del_vq(vi->rvq);

31
drivers/virtio/Kconfig
View file

@ -1,8 +1,35 @@
# Virtio always gets selected by whoever wants it.
config VIRTIO
bool
tristate
# Similarly the virtio ring implementation.
config VIRTIO_RING
bool
tristate
depends on VIRTIO
config VIRTIO_PCI
tristate "PCI driver for virtio devices (EXPERIMENTAL)"
depends on PCI && EXPERIMENTAL
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
virtio backends. Most QEMU based VMMs should support these devices
(like KVM or Xen).
Currently, the ABI is not considered stable so there is no guarantee
that this version of the driver will work with your VMM.
If unsure, say M.
config VIRTIO_BALLOON
tristate "Virtio balloon driver (EXPERIMENTAL)"
select VIRTIO
select VIRTIO_RING
---help---
This driver supports increasing and decreasing the amount
of memory within a KVM guest.
If unsure, say M.

2
drivers/virtio/Makefile
View file

@ -1,2 +1,4 @@
obj-$(CONFIG_VIRTIO) += virtio.o
obj-$(CONFIG_VIRTIO_RING) += virtio_ring.o
obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o

65
drivers/virtio/virtio.c
View file

@ -102,9 +102,13 @@ static int virtio_dev_remove(struct device *_d)
struct virtio_driver *drv = container_of(dev->dev.driver,
struct virtio_driver, driver);
dev->config->set_status(dev, dev->config->get_status(dev)
& ~VIRTIO_CONFIG_S_DRIVER);
drv->remove(dev);
/* Driver should have reset device. */
BUG_ON(dev->config->get_status(dev));
/* Acknowledge the device's existence again. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
return 0;
}
@ -130,6 +134,10 @@ int register_virtio_device(struct virtio_device *dev)
dev->dev.bus = &virtio_bus;
sprintf(dev->dev.bus_id, "%u", dev->index);
/* We always start by resetting the device, in case a previous
* driver messed it up. This also tests that code path a little. */
dev->config->reset(dev);
/* Acknowledge that we've seen the device. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
@ -148,55 +156,18 @@ void unregister_virtio_device(struct virtio_device *dev)
}
EXPORT_SYMBOL_GPL(unregister_virtio_device);
int __virtio_config_val(struct virtio_device *vdev,
u8 type, void *val, size_t size)
{
void *token;
unsigned int len;
token = vdev->config->find(vdev, type, &len);
if (!token)
return -ENOENT;
if (len != size)
return -EIO;
vdev->config->get(vdev, token, val, size);
return 0;
}
EXPORT_SYMBOL_GPL(__virtio_config_val);
int virtio_use_bit(struct virtio_device *vdev,
void *token, unsigned int len, unsigned int bitnum)
{
unsigned long bits[16];
/* This makes it convenient to pass-through find() results. */
if (!token)
return 0;
/* bit not in range of this bitfield? */
if (bitnum * 8 >= len / 2)
return 0;
/* Giant feature bitfields are silly. */
BUG_ON(len > sizeof(bits));
vdev->config->get(vdev, token, bits, len);
if (!test_bit(bitnum, bits))
return 0;
/* Set acknowledge bit, and write it back. */
set_bit(bitnum + len * 8 / 2, bits);
vdev->config->set(vdev, token, bits, len);
return 1;
}
EXPORT_SYMBOL_GPL(virtio_use_bit);
static int virtio_init(void)
{
if (bus_register(&virtio_bus) != 0)
panic("virtio bus registration failed");
return 0;
}
static void __exit virtio_exit(void)
{
bus_unregister(&virtio_bus);
}
core_initcall(virtio_init);
module_exit(virtio_exit);
MODULE_LICENSE("GPL");

284
drivers/virtio/virtio_balloon.c Normal file
View file

@ -0,0 +1,284 @@
/* Virtio balloon implementation, inspired by Dor Loar and Marcelo
* Tosatti's implementations.
*
* Copyright 2008 Rusty Russell IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* 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>
#include <linux/kthread.h>
#include <linux/freezer.h>
struct virtio_balloon
{
struct virtio_device *vdev;
struct virtqueue *inflate_vq, *deflate_vq;
/* Where the ballooning thread waits for config to change. */
wait_queue_head_t config_change;
/* The thread servicing the balloon. */
struct task_struct *thread;
/* Waiting for host to ack the pages we released. */
struct completion acked;
/* Do we have to tell Host *before* we reuse pages? */
bool tell_host_first;
/* The pages we've told the Host we're not using. */
unsigned int num_pages;
struct list_head pages;
/* The array of pfns we tell the Host about. */
unsigned int num_pfns;
u32 pfns[256];
};
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_BALLOON, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static void balloon_ack(struct virtqueue *vq)
{
struct virtio_balloon *vb;
unsigned int len;
vb = vq->vq_ops->get_buf(vq, &len);
if (vb)
complete(&vb->acked);
}
static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
{
struct scatterlist sg;
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 (vq->vq_ops->add_buf(vq, &sg, 1, 0, vb) != 0)
BUG();
vq->vq_ops->kick(vq);
/* When host has read buffer, this completes via balloon_ack */
wait_for_completion(&vb->acked);
}
static void fill_balloon(struct virtio_balloon *vb, size_t num)
{
/* 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);
if (!page) {
if (printk_ratelimit())
dev_printk(KERN_INFO, &vb->vdev->dev,
"Out of puff! Can't get %zu pages\n",
num);
/* Sleep for at least 1/5 of a second before retry. */
msleep(200);
break;
}
vb->pfns[vb->num_pfns] = page_to_pfn(page);
totalram_pages--;
vb->num_pages++;
list_add(&page->lru, &vb->pages);
}
/* Didn't get any? Oh well. */
if (vb->num_pfns == 0)
return;
tell_host(vb, vb->inflate_vq);
}
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++;
}
}
static void leak_balloon(struct virtio_balloon *vb, size_t num)
{
struct page *page;
/* 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_pfn(page);
vb->num_pages--;
}
if (vb->tell_host_first) {
tell_host(vb, vb->deflate_vq);
release_pages_by_pfn(vb->pfns, vb->num_pfns);
} else {
release_pages_by_pfn(vb->pfns, vb->num_pfns);
tell_host(vb, vb->deflate_vq);
}
}
static void virtballoon_changed(struct virtio_device *vdev)
{
struct virtio_balloon *vb = vdev->priv;
wake_up(&vb->config_change);
}
static inline int towards_target(struct virtio_balloon *vb)
{
u32 v;
__virtio_config_val(vb->vdev,
offsetof(struct virtio_balloon_config, num_pages),
&v);
return v - 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));
}
static int balloon(void *_vballoon)
{
struct virtio_balloon *vb = _vballoon;
set_freezable();
while (!kthread_should_stop()) {
int diff;
try_to_freeze();
wait_event_interruptible(vb->config_change,
(diff = towards_target(vb)) != 0
|| kthread_should_stop());
if (diff > 0)
fill_balloon(vb, diff);
else if (diff < 0)
leak_balloon(vb, -diff);
update_balloon_size(vb);
}
return 0;
}
static int virtballoon_probe(struct virtio_device *vdev)
{
struct virtio_balloon *vb;
int err;
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;
/* We expect two virtqueues. */
vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack);
if (IS_ERR(vb->inflate_vq)) {
err = PTR_ERR(vb->inflate_vq);
goto out_free_vb;
}
vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack);
if (IS_ERR(vb->deflate_vq)) {
err = PTR_ERR(vb->deflate_vq);
goto out_del_inflate_vq;
}
vb->thread = kthread_run(balloon, vb, "vballoon");
if (IS_ERR(vb->thread)) {
err = PTR_ERR(vb->thread);
goto out_del_deflate_vq;
}
vb->tell_host_first
= vdev->config->feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST);
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_free_vb:
kfree(vb);
out:
return err;
}
static void virtballoon_remove(struct virtio_device *vdev)
{
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);
/* 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);
kfree(vb);
}
static struct virtio_driver virtio_balloon = {
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtballoon_probe,
.remove = __devexit_p(virtballoon_remove),
.config_changed = virtballoon_changed,
};
static int __init init(void)
{
return register_virtio_driver(&virtio_balloon);
}
static void __exit fini(void)
{
unregister_virtio_driver(&virtio_balloon);
}
module_init(init);
module_exit(fini);
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio balloon driver");
MODULE_LICENSE("GPL");

446
drivers/virtio/virtio_pci.c Normal file
View file

@ -0,0 +1,446 @@
/*
* Virtio PCI driver
*
* This module allows virtio devices to be used over a virtual PCI device.
* This can be used with QEMU based VMMs like KVM or Xen.
*
* Copyright IBM Corp. 2007
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include <linux/module.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_pci.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
MODULE_AUTHOR("Anthony Liguori <[email protected]>");
MODULE_DESCRIPTION("virtio-pci");
MODULE_LICENSE("GPL");
MODULE_VERSION("1");
/* Our device structure */
struct virtio_pci_device
{
struct virtio_device vdev;
struct pci_dev *pci_dev;
/* the IO mapping for the PCI config space */
void *ioaddr;
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
};
struct virtio_pci_vq_info
{
/* the actual virtqueue */
struct virtqueue *vq;
/* 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;
/* the list node for the virtqueues list */
struct list_head node;
};
/* 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 },
};
MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
/* A PCI device has it's own struct device and so does a virtio device so
* we create a place for the virtio devices to show up in sysfs. I think it
* would make more sense for virtio to not insist on having it's own device. */
static struct device virtio_pci_root = {
.parent = NULL,
.bus_id = "virtio-pci",
};
/* Unique numbering for devices under the kvm root */
static unsigned int dev_index;
/* Convert a generic virtio device to our structure */
static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
{
return container_of(vdev, struct virtio_pci_device, vdev);
}
/* virtio config->feature() implementation */
static bool vp_feature(struct virtio_device *vdev, unsigned bit)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
u32 mask;
/* Since this function is supposed to have the side effect of
* enabling a queried feature, we simulate that by doing a read
* from the host feature bitmask and then writing to the guest
* feature bitmask */
mask = ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
if (mask & (1 << bit)) {
mask |= (1 << bit);
iowrite32(mask, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
}
return !!(mask & (1 << bit));
}
/* virtio config->get() implementation */
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 *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
u8 *ptr = buf;
int i;
for (i = 0; i < len; i++)
ptr[i] = ioread8(ioaddr + i);
}
/* the config->set() implementation. it's symmetric to the config->get()
* implementation */
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 *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
const u8 *ptr = buf;
int i;
for (i = 0; i < len; i++)
iowrite8(ptr[i], ioaddr + i);
}
/* config->{get,set}_status() implementations */
static u8 vp_get_status(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}
static void vp_set_status(struct virtio_device *vdev, u8 status)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* We should never be setting status to 0. */
BUG_ON(status == 0);
return iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}
static void vp_reset(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* 0 status means a reset. */
return iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}
/* the notify function used when creating a virt queue */
static void 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);
}
/* 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
* the callback may notify the host which results in the host attempting to
* raise an interrupt that we would then mask once we acknowledged the
* interrupt. */
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;
u8 isr;
/* reading the ISR has the effect of also clearing it so it's very
* important to save off the value. */
isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
/* It's definitely not us if the ISR was not high */
if (!isr)
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->config_changed)
drv->config_changed(&vp_dev->vdev);
}
spin_lock(&vp_dev->lock);
list_for_each_entry(info, &vp_dev->virtqueues, node) {
if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
ret = IRQ_HANDLED;
}
spin_unlock(&vp_dev->lock);
return ret;
}
/* the config->find_vq() implementation */
static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
void (*callback)(struct virtqueue *vq))
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_vq_info *info;
struct virtqueue *vq;
u16 num;
int err;
/* Select the queue we're interested in */
iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
/* Check if queue is either not available or already active. */
num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
return ERR_PTR(-ENOENT);
/* allocate and fill out our structure the represents an active
* queue */
info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
if (!info)
return ERR_PTR(-ENOMEM);
info->queue_index = index;
info->num = num;
info->queue = kzalloc(PAGE_ALIGN(vring_size(num,PAGE_SIZE)), GFP_KERNEL);
if (info->queue == NULL) {
err = -ENOMEM;
goto out_info;
}
/* activate the queue */
iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT,
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
/* create the vring */
vq = vring_new_virtqueue(info->num, vdev, info->queue,
vp_notify, callback);
if (!vq) {
err = -ENOMEM;
goto out_activate_queue;
}
vq->priv = info;
info->vq = vq;
spin_lock(&vp_dev->lock);
list_add(&info->node, &vp_dev->virtqueues);
spin_unlock(&vp_dev->lock);
return vq;
out_activate_queue:
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
kfree(info->queue);
out_info:
kfree(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;
spin_lock(&vp_dev->lock);
list_del(&info->node);
spin_unlock(&vp_dev->lock);
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);
kfree(info->queue);
kfree(info);
}
static struct virtio_config_ops virtio_pci_config_ops = {
.feature = vp_feature,
.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,
};
/* the PCI probing function */
static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
const struct pci_device_id *id)
{
struct virtio_pci_device *vp_dev;
int err;
/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
return -ENODEV;
if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
return -ENODEV;
}
/* allocate our structure and fill it out */
vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
if (vp_dev == NULL)
return -ENOMEM;
snprintf(vp_dev->vdev.dev.bus_id, BUS_ID_SIZE, "virtio%d", dev_index);
vp_dev->vdev.index = dev_index;
dev_index++;
vp_dev->vdev.dev.parent = &virtio_pci_root;
vp_dev->vdev.config = &virtio_pci_config_ops;
vp_dev->pci_dev = pci_dev;
INIT_LIST_HEAD(&vp_dev->virtqueues);
spin_lock_init(&vp_dev->lock);
/* enable the device */
err = pci_enable_device(pci_dev);
if (err)
goto out;
err = pci_request_regions(pci_dev, "virtio-pci");
if (err)
goto out_enable_device;
vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
if (vp_dev->ioaddr == NULL)
goto out_req_regions;
pci_set_drvdata(pci_dev, vp_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
* virtio devices and to identify the particular virtio driver by
* the subsytem ids */
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,
vp_dev->vdev.dev.bus_id, 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;
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);
out_req_regions:
pci_release_regions(pci_dev);
out_enable_device:
pci_disable_device(pci_dev);
out:
kfree(vp_dev);
return err;
}
static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
{
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
free_irq(pci_dev->irq, vp_dev);
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)
{
pci_save_state(pci_dev);
pci_set_power_state(pci_dev, PCI_D3hot);
return 0;
}
static int virtio_pci_resume(struct pci_dev *pci_dev)
{
pci_restore_state(pci_dev);
pci_set_power_state(pci_dev, PCI_D0);
return 0;
}
#endif
static struct pci_driver virtio_pci_driver = {
.name = "virtio-pci",
.id_table = virtio_pci_id_table,
.probe = virtio_pci_probe,
.remove = virtio_pci_remove,
#ifdef CONFIG_PM
.suspend = virtio_pci_suspend,
.resume = virtio_pci_resume,
#endif
};
static int __init virtio_pci_init(void)
{
int err;
err = device_register(&virtio_pci_root);
if (err)
return err;
err = pci_register_driver(&virtio_pci_driver);
if (err)
device_unregister(&virtio_pci_root);
return err;
}
module_init(virtio_pci_init);
static void __exit virtio_pci_exit(void)
{
device_unregister(&virtio_pci_root);
pci_unregister_driver(&virtio_pci_driver);
}
module_exit(virtio_pci_exit);

51
drivers/virtio/virtio_ring.c
View file

@ -87,6 +87,8 @@ static int vring_add_buf(struct virtqueue *_vq,
if (vq->num_free < out + in) {
pr_debug("Can't add buf len %i - avail = %i\n",
out + in, vq->num_free);
/* We notify *even if* VRING_USED_F_NO_NOTIFY is set here. */
vq->notify(&vq->vq);
END_USE(vq);
return -ENOSPC;
}
@ -97,16 +99,14 @@ static int vring_add_buf(struct virtqueue *_vq,
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 = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
+ sg->offset;
vq->vring.desc[i].addr = sg_phys(sg);
vq->vring.desc[i].len = sg->length;
prev = i;
sg++;
}
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 = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
+ sg->offset;
vq->vring.desc[i].addr = sg_phys(sg);
vq->vring.desc[i].len = sg->length;
prev = i;
sg++;
@ -171,16 +171,6 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
vq->num_free++;
}
/* FIXME: We need to tell other side about removal, to synchronize. */
static void vring_shutdown(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
unsigned int i;
for (i = 0; i < vq->vring.num; i++)
detach_buf(vq, i);
}
static inline bool more_used(const struct vring_virtqueue *vq)
{
return vq->last_used_idx != vq->vring.used->idx;
@ -220,7 +210,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
return ret;
}
static bool vring_restart(struct virtqueue *_vq)
static void vring_disable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
START_USE(vq);
BUG_ON(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT);
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
END_USE(vq);
}
static bool vring_enable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@ -253,26 +253,34 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
if (unlikely(vq->broken))
return IRQ_HANDLED;
/* Other side may have missed us turning off the interrupt,
* but we should preserve disable semantic for virtio users. */
if (unlikely(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
pr_debug("virtqueue interrupt after disable for %p\n", vq);
return IRQ_HANDLED;
}
pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
if (vq->vq.callback && !vq->vq.callback(&vq->vq))
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
if (vq->vq.callback)
vq->vq.callback(&vq->vq);
return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(vring_interrupt);
static struct virtqueue_ops vring_vq_ops = {
.add_buf = vring_add_buf,
.get_buf = vring_get_buf,
.kick = vring_kick,
.restart = vring_restart,
.shutdown = vring_shutdown,
.disable_cb = vring_disable_cb,
.enable_cb = vring_enable_cb,
};
struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *),
bool (*callback)(struct virtqueue *))
void (*callback)(struct virtqueue *))
{
struct vring_virtqueue *vq;
unsigned int i;
@ -311,9 +319,12 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
return &vq->vq;
}
EXPORT_SYMBOL_GPL(vring_new_virtqueue);
void vring_del_virtqueue(struct virtqueue *vq)
{
kfree(to_vvq(vq));
}
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
MODULE_LICENSE("GPL");