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

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* 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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

233
Documentation/lguest/lguest.c
View File

@ -34,6 +34,8 @@
#include <zlib.h>
#include <assert.h>
#include <sched.h>
#include <limits.h>
#include <stddef.h>
#include "linux/lguest_launcher.h"
#include "linux/virtio_config.h"
#include "linux/virtio_net.h"
@ -99,13 +101,11 @@ struct device_list
/* The descriptor page for the devices. */
u8 *descpage;
/* The tail of the last descriptor. */
unsigned int desc_used;
/* A single linked list of devices. */
struct device *dev;
/* ... And an end pointer so we can easily append new devices */
struct device **lastdev;
/* And a pointer to the last device for easy append and also for
* configuration appending. */
struct device *lastdev;
};
/* The list of Guest devices, based on command line arguments. */
@ -191,7 +191,14 @@ static void *_convert(struct iovec *iov, size_t size, size_t align,
#define cpu_to_le64(v64) (v64)
#define le16_to_cpu(v16) (v16)
#define le32_to_cpu(v32) (v32)
#define le64_to_cpu(v32) (v64)
#define le64_to_cpu(v64) (v64)
/* The device virtqueue descriptors are followed by feature bitmasks. */
static u8 *get_feature_bits(struct device *dev)
{
return (u8 *)(dev->desc + 1)
+ dev->desc->num_vq * sizeof(struct lguest_vqconfig);
}
/*L:100 The Launcher code itself takes us out into userspace, that scary place
* where pointers run wild and free! Unfortunately, like most userspace
@ -914,21 +921,58 @@ static void enable_fd(int fd, struct virtqueue *vq)
write(waker_fd, &vq->dev->fd, sizeof(vq->dev->fd));
}
/* Resetting a device is fairly easy. */
static void reset_device(struct device *dev)
{
struct virtqueue *vq;
verbose("Resetting device %s\n", dev->name);
/* Clear the status. */
dev->desc->status = 0;
/* Clear any features they've acked. */
memset(get_feature_bits(dev) + dev->desc->feature_len, 0,
dev->desc->feature_len);
/* Zero out the virtqueues. */
for (vq = dev->vq; vq; vq = vq->next) {
memset(vq->vring.desc, 0,
vring_size(vq->config.num, getpagesize()));
vq->last_avail_idx = 0;
}
}
/* This is the generic routine we call when the Guest uses LHCALL_NOTIFY. */
static void handle_output(int fd, unsigned long addr)
{
struct device *i;
struct virtqueue *vq;
/* Check each virtqueue. */
/* Check each device and virtqueue. */
for (i = devices.dev; i; i = i->next) {
/* Notifications to device descriptors reset the device. */
if (from_guest_phys(addr) == i->desc) {
reset_device(i);
return;
}
/* Notifications to virtqueues mean output has occurred. */
for (vq = i->vq; vq; vq = vq->next) {
if (vq->config.pfn == addr/getpagesize()
&& vq->handle_output) {
verbose("Output to %s\n", vq->dev->name);
vq->handle_output(fd, vq);
if (vq->config.pfn != addr/getpagesize())
continue;
/* Guest should acknowledge (and set features!) before
* using the device. */
if (i->desc->status == 0) {
warnx("%s gave early output", i->name);
return;
}
if (strcmp(vq->dev->name, "console") != 0)
verbose("Output to %s\n", vq->dev->name);
if (vq->handle_output)
vq->handle_output(fd, vq);
return;
}
}
@ -986,54 +1030,44 @@ static void handle_input(int fd)
*
* All devices need a descriptor so the Guest knows it exists, and a "struct
* device" so the Launcher can keep track of it. We have common helper
* routines to allocate them.
*
* This routine allocates a new "struct lguest_device_desc" from descriptor
* table just above the Guest's normal memory. It returns a pointer to that
* descriptor. */
* routines to allocate and manage them. */
/* The layout of the device page is a "struct lguest_device_desc" followed by a
* number of virtqueue descriptors, then two sets of feature bits, then an
* array of configuration bytes. This routine returns the configuration
* pointer. */
static u8 *device_config(const struct device *dev)
{
return (void *)(dev->desc + 1)
+ dev->desc->num_vq * sizeof(struct lguest_vqconfig)
+ dev->desc->feature_len * 2;
}
/* This routine allocates a new "struct lguest_device_desc" from descriptor
* table page just above the Guest's normal memory. It returns a pointer to
* that descriptor. */
static struct lguest_device_desc *new_dev_desc(u16 type)
{
struct lguest_device_desc *d;
struct lguest_device_desc d = { .type = type };
void *p;
/* Figure out where the next device config is, based on the last one. */
if (devices.lastdev)
p = device_config(devices.lastdev)
+ devices.lastdev->desc->config_len;
else
p = devices.descpage;
/* We only have one page for all the descriptors. */
if (devices.desc_used + sizeof(*d) > getpagesize())
if (p + sizeof(d) > (void *)devices.descpage + getpagesize())
errx(1, "Too many devices");
/* We don't need to set config_len or status: page is 0 already. */
d = (void *)devices.descpage + devices.desc_used;
d->type = type;
devices.desc_used += sizeof(*d);
return d;
/* p might not be aligned, so we memcpy in. */
return memcpy(p, &d, sizeof(d));
}
/* Each device descriptor is followed by some configuration information.
* Each configuration field looks like: u8 type, u8 len, [... len bytes...].
*
* This routine adds a new field to an existing device's descriptor. It only
* works for the last device, but that's OK because that's how we use it. */
static void add_desc_field(struct device *dev, u8 type, u8 len, const void *c)
{
/* This is the last descriptor, right? */
assert(devices.descpage + devices.desc_used
== (u8 *)(dev->desc + 1) + dev->desc->config_len);
/* We only have one page of device descriptions. */
if (devices.desc_used + 2 + len > getpagesize())
errx(1, "Too many devices");
/* Copy in the new config header: type then length. */
devices.descpage[devices.desc_used++] = type;
devices.descpage[devices.desc_used++] = len;
memcpy(devices.descpage + devices.desc_used, c, len);
devices.desc_used += len;
/* Update the device descriptor length: two byte head then data. */
dev->desc->config_len += 2 + len;
}
/* This routine adds a virtqueue to a device. We specify how many descriptors
* the virtqueue is to have. */
/* Each device descriptor is followed by the description of its virtqueues. We
* specify how many descriptors the virtqueue is to have. */
static void add_virtqueue(struct device *dev, unsigned int num_descs,
void (*handle_output)(int fd, struct virtqueue *me))
{
@ -1059,9 +1093,15 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
/* Initialize the vring. */
vring_init(&vq->vring, num_descs, p, getpagesize());
/* Add the configuration information to this device's descriptor. */
add_desc_field(dev, VIRTIO_CONFIG_F_VIRTQUEUE,
sizeof(vq->config), &vq->config);
/* Append virtqueue to this device's descriptor. We use
* device_config() to get the end of the device's current virtqueues;
* we check that we haven't added any config or feature information
* yet, otherwise we'd be overwriting them. */
assert(dev->desc->config_len == 0 && dev->desc->feature_len == 0);
memcpy(device_config(dev), &vq->config, sizeof(vq->config));
dev->desc->num_vq++;
verbose("Virtqueue page %#lx\n", to_guest_phys(p));
/* Add to tail of list, so dev->vq is first vq, dev->vq->next is
* second. */
@ -1072,11 +1112,41 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
* virtqueue. */
vq->handle_output = handle_output;
/* Set the "Don't Notify Me" flag if we don't have a handler */
/* As an optimization, set the advisory "Don't Notify Me" flag if we
* don't have a handler */
if (!handle_output)
vq->vring.used->flags = VRING_USED_F_NO_NOTIFY;
}
/* The first half of the feature bitmask is for us to advertise features. The
* second half if for the Guest to accept features. */
static void add_feature(struct device *dev, unsigned bit)
{
u8 *features = get_feature_bits(dev);
/* We can't extend the feature bits once we've added config bytes */
if (dev->desc->feature_len <= bit / CHAR_BIT) {
assert(dev->desc->config_len == 0);
dev->desc->feature_len = (bit / CHAR_BIT) + 1;
}
features[bit / CHAR_BIT] |= (1 << (bit % CHAR_BIT));
}
/* This routine sets the configuration fields for an existing device's
* descriptor. It only works for the last device, but that's OK because that's
* how we use it. */
static void set_config(struct device *dev, unsigned len, const void *conf)
{
/* Check we haven't overflowed our single page. */
if (device_config(dev) + len > devices.descpage + getpagesize())
errx(1, "Too many devices");
/* Copy in the config information, and store the length. */
memcpy(device_config(dev), conf, len);
dev->desc->config_len = len;
}
/* This routine does all the creation and setup of a new device, including
* calling new_dev_desc() to allocate the descriptor and device memory. */
static struct device *new_device(const char *name, u16 type, int fd,
@ -1084,14 +1154,6 @@ static struct device *new_device(const char *name, u16 type, int fd,
{
struct device *dev = malloc(sizeof(*dev));
/* Append to device list. Prepending to a single-linked list is
* easier, but the user expects the devices to be arranged on the bus
* in command-line order. The first network device on the command line
* is eth0, the first block device /dev/vda, etc. */
*devices.lastdev = dev;
dev->next = NULL;
devices.lastdev = &dev->next;
/* Now we populate the fields one at a time. */
dev->fd = fd;
/* If we have an input handler for this file descriptor, then we add it
@ -1102,6 +1164,17 @@ static struct device *new_device(const char *name, u16 type, int fd,
dev->handle_input = handle_input;
dev->name = name;
dev->vq = NULL;
/* Append to device list. Prepending to a single-linked list is
* easier, but the user expects the devices to be arranged on the bus
* in command-line order. The first network device on the command line
* is eth0, the first block device /dev/vda, etc. */
if (devices.lastdev)
devices.lastdev->next = dev;
else
devices.dev = dev;
devices.lastdev = dev;
return dev;
}
@ -1226,7 +1299,7 @@ static void setup_tun_net(const char *arg)
int netfd, ipfd;
u32 ip;
const char *br_name = NULL;
u8 hwaddr[6];
struct virtio_net_config conf;
/* We open the /dev/net/tun device and tell it we want a tap device. A
* tap device is like a tun device, only somehow different. To tell
@ -1265,12 +1338,13 @@ static void setup_tun_net(const char *arg)
ip = str2ip(arg);
/* Set up the tun device, and get the mac address for the interface. */
configure_device(ipfd, ifr.ifr_name, ip, hwaddr);
configure_device(ipfd, ifr.ifr_name, ip, conf.mac);
/* Tell Guest what MAC address to use. */
add_desc_field(dev, VIRTIO_CONFIG_NET_MAC_F, sizeof(hwaddr), hwaddr);
add_feature(dev, VIRTIO_NET_F_MAC);
set_config(dev, sizeof(conf), &conf);
/* We don't seed the socket any more; setup is done. */
/* We don't need the socket any more; setup is done. */
close(ipfd);
verbose("device %u: tun net %u.%u.%u.%u\n",
@ -1458,8 +1532,7 @@ static void setup_block_file(const char *filename)
struct device *dev;
struct vblk_info *vblk;
void *stack;
u64 cap;
unsigned int val;
struct virtio_blk_config conf;
/* This is the pipe the I/O thread will use to tell us I/O is done. */
pipe(p);
@ -1477,14 +1550,18 @@ static void setup_block_file(const char *filename)
vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE);
vblk->len = lseek64(vblk->fd, 0, SEEK_END);
/* We support barriers. */
add_feature(dev, VIRTIO_BLK_F_BARRIER);
/* Tell Guest how many sectors this device has. */
cap = cpu_to_le64(vblk->len / 512);
add_desc_field(dev, VIRTIO_CONFIG_BLK_F_CAPACITY, sizeof(cap), &cap);
conf.capacity = cpu_to_le64(vblk->len / 512);
/* Tell Guest not to put in too many descriptors at once: two are used
* for the in and out elements. */
val = cpu_to_le32(VIRTQUEUE_NUM - 2);
add_desc_field(dev, VIRTIO_CONFIG_BLK_F_SEG_MAX, sizeof(val), &val);
add_feature(dev, VIRTIO_BLK_F_SEG_MAX);
conf.seg_max = cpu_to_le32(VIRTQUEUE_NUM - 2);
set_config(dev, sizeof(conf), &conf);
/* The I/O thread writes to this end of the pipe when done. */
vblk->done_fd = p[1];
@ -1505,7 +1582,7 @@ static void setup_block_file(const char *filename)
close(vblk->workpipe[0]);
verbose("device %u: virtblock %llu sectors\n",
devices.device_num, cap);
devices.device_num, le64_to_cpu(conf.capacity));
}
/* That's the end of device setup. :*/
@ -1610,12 +1687,12 @@ int main(int argc, char *argv[])
/* First we initialize the device list. Since console and network
* device receive input from a file descriptor, we keep an fdset
* (infds) and the maximum fd number (max_infd) with the head of the
* list. We also keep a pointer to the last device, for easy appending
* to the list. Finally, we keep the next interrupt number to hand out
* (1: remember that 0 is used by the timer). */
* list. We also keep a pointer to the last device. Finally, we keep
* the next interrupt number to hand out (1: remember that 0 is used by
* the timer). */
FD_ZERO(&devices.infds);
devices.max_infd = -1;
devices.lastdev = &devices.dev;
devices.lastdev = NULL;
devices.next_irq = 1;
cpu_id = 0;

1
arch/x86/kvm/Kconfig
View File

@ -53,5 +53,6 @@ config KVM_AMD
# OK, it's a little counter-intuitive to do this, but it puts it neatly under
# the virtualization menu.
source drivers/lguest/Kconfig
source drivers/virtio/Kconfig
endif # VIRTUALIZATION

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 <aliguori@us.ibm.com>");
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");

9
include/linux/lguest_launcher.h
View File

@ -23,7 +23,12 @@
struct lguest_device_desc {
/* The device type: console, network, disk etc. Type 0 terminates. */
__u8 type;
/* The number of bytes of the config array. */
/* The number of virtqueues (first in config array) */
__u8 num_vq;
/* The number of bytes of feature bits. Multiply by 2: one for host
* features and one for guest acknowledgements. */
__u8 feature_len;
/* The number of bytes of the config array after virtqueues. */
__u8 config_len;
/* A status byte, written by the Guest. */
__u8 status;
@ -31,7 +36,7 @@ struct lguest_device_desc {
};
/*D:135 This is how we expect the device configuration field for a virtqueue
* (type VIRTIO_CONFIG_F_VIRTQUEUE) to be laid out: */
* to be laid out in config space. */
struct lguest_vqconfig {
/* The number of entries in the virtio_ring */
__u16 num;

1
include/linux/skbuff.h
View File

@ -1810,5 +1810,6 @@ static inline void skb_forward_csum(struct sk_buff *skb)
skb->ip_summed = CHECKSUM_NONE;
}
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
#endif /* __KERNEL__ */
#endif /* _LINUX_SKBUFF_H */

19
include/linux/virtio.h
View File

@ -11,15 +11,13 @@
/**
* virtqueue - a queue to register buffers for sending or receiving.
* @callback: the function to call when buffers are consumed (can be NULL).
* If this returns false, callbacks are suppressed until vq_ops->restart
* is called.
* @vdev: the virtio device this queue was created for.
* @vq_ops: the operations for this virtqueue (see below).
* @priv: a pointer for the virtqueue implementation to use.
*/
struct virtqueue
{
bool (*callback)(struct virtqueue *vq);
void (*callback)(struct virtqueue *vq);
struct virtio_device *vdev;
struct virtqueue_ops *vq_ops;
void *priv;
@ -41,13 +39,12 @@ struct virtqueue
* vq: the struct virtqueue we're talking about.
* len: the length written into the buffer
* Returns NULL or the "data" token handed to add_buf.
* @restart: restart callbacks after callback returned false.
* @disable_cb: disable callbacks
* vq: the struct virtqueue we're talking about.
* @enable_cb: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
* This returns "false" (and doesn't re-enable) if there are pending
* buffers in the queue, to avoid a race.
* @shutdown: "unadd" all buffers.
* vq: the struct virtqueue we're talking about.
* Remove everything from the queue.
*
* Locking rules are straightforward: the driver is responsible for
* locking. No two operations may be invoked simultaneously.
@ -65,9 +62,8 @@ struct virtqueue_ops {
void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
bool (*restart)(struct virtqueue *vq);
void (*shutdown)(struct virtqueue *vq);
void (*disable_cb)(struct virtqueue *vq);
bool (*enable_cb)(struct virtqueue *vq);
};
/**
@ -97,12 +93,15 @@ void unregister_virtio_device(struct virtio_device *dev);
* @probe: the function to call when a device is found. Returns a token for
* remove, or PTR_ERR().
* @remove: the function when a device is removed.
* @config_changed: optional function to call when the device configuration
* changes; may be called in interrupt context.
*/
struct virtio_driver {
struct device_driver driver;
const struct virtio_device_id *id_table;
int (*probe)(struct virtio_device *dev);
void (*remove)(struct virtio_device *dev);
void (*config_changed)(struct virtio_device *dev);
};
int register_virtio_driver(struct virtio_driver *drv);

18
include/linux/virtio_balloon.h Normal file
View File

@ -0,0 +1,18 @@
#ifndef _LINUX_VIRTIO_BALLOON_H
#define _LINUX_VIRTIO_BALLOON_H
#include <linux/virtio_config.h>
/* The ID for virtio_balloon */
#define VIRTIO_ID_BALLOON 5
/* The feature bitmap for virtio balloon */
#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
struct virtio_balloon_config
{
/* Number of pages host wants Guest to give up. */
__le32 num_pages;
/* Number of pages we've actually got in balloon. */
__le32 actual;
};
#endif /* _LINUX_VIRTIO_BALLOON_H */

22
include/linux/virtio_blk.h
View File

@ -6,15 +6,19 @@
#define VIRTIO_ID_BLOCK 2
/* Feature bits */
#define VIRTIO_CONFIG_BLK_F 0x40
#define VIRTIO_BLK_F_BARRIER 1 /* Does host support barriers? */
#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
/* The capacity (in 512-byte sectors). */
#define VIRTIO_CONFIG_BLK_F_CAPACITY 0x41
/* The maximum segment size. */
#define VIRTIO_CONFIG_BLK_F_SIZE_MAX 0x42
/* The maximum number of segments. */
#define VIRTIO_CONFIG_BLK_F_SEG_MAX 0x43
struct virtio_blk_config
{
/* The capacity (in 512-byte sectors). */
__le64 capacity;
/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
__le32 size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
__le32 seg_max;
} __attribute__((packed));
/* These two define direction. */
#define VIRTIO_BLK_T_IN 0
@ -35,8 +39,6 @@ struct virtio_blk_outhdr
__u32 ioprio;
/* Sector (ie. 512 byte offset) */
__u64 sector;
/* Where to put reply. */
__u64 id;
};
#define VIRTIO_BLK_S_OK 0

104
include/linux/virtio_config.h
View File

@ -5,7 +5,7 @@
* store and access that space differently. */
#include <linux/types.h>
/* Status byte for guest to report progress, and synchronize config. */
/* Status byte for guest to report progress, and synchronize features. */
/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
/* We have found a driver for the device. */
@ -15,34 +15,27 @@
/* We've given up on this device. */
#define VIRTIO_CONFIG_S_FAILED 0x80
/* Feature byte (actually 7 bits availabe): */
/* Requirements/features of the virtio implementation. */
#define VIRTIO_CONFIG_F_VIRTIO 1
/* Requirements/features of the virtqueue (may have more than one). */
#define VIRTIO_CONFIG_F_VIRTQUEUE 2
#ifdef __KERNEL__
struct virtio_device;
/**
* virtio_config_ops - operations for configuring a virtio device
* @find: search for the next configuration field of the given type.
* @feature: search for a feature in this config
* vdev: the virtio_device
* type: the feature type
* len: the (returned) length of the field if found.
* Returns a token if found, or NULL. Never returnes the same field twice
* (ie. it's used up).
* @get: read the value of a configuration field after find().
* bit: the feature bit
* Returns true if the feature is supported. Acknowledges the feature
* so the host can see it.
* @get: read the value of a configuration field
* vdev: the virtio_device
* token: the token returned from find().
* offset: the offset of the configuration field
* buf: the buffer to write the field value into.
* len: the length of the buffer (given by find()).
* len: the length of the buffer
* Note that contents are conventionally little-endian.
* @set: write the value of a configuration field after find().
* @set: write the value of a configuration field
* vdev: the virtio_device
* token: the token returned from find().
* offset: the offset of the configuration field
* buf: the buffer to read the field value from.
* len: the length of the buffer (given by find()).
* len: the length of the buffer
* Note that contents are conventionally little-endian.
* @get_status: read the status byte
* vdev: the virtio_device
@ -50,62 +43,67 @@ struct virtio_device;
* @set_status: write the status byte
* vdev: the virtio_device
* status: the new status byte
* @find_vq: find the first VIRTIO_CONFIG_F_VIRTQUEUE and create a virtqueue.
* @reset: reset the device
* vdev: the virtio device
* After this, status and feature negotiation must be done again
* @find_vq: find a virtqueue and instantiate it.
* vdev: the virtio_device
* index: the 0-based virtqueue number in case there's more than one.
* callback: the virqtueue callback
* Returns the new virtqueue or ERR_PTR().
* Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
* @del_vq: free a virtqueue found by find_vq().
*/
struct virtio_config_ops
{
void *(*find)(struct virtio_device *vdev, u8 type, unsigned *len);
void (*get)(struct virtio_device *vdev, void *token,
bool (*feature)(struct virtio_device *vdev, unsigned bit);
void (*get)(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len);
void (*set)(struct virtio_device *vdev, void *token,
void (*set)(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len);
u8 (*get_status)(struct virtio_device *vdev);
void (*set_status)(struct virtio_device *vdev, u8 status);
void (*reset)(struct virtio_device *vdev);
struct virtqueue *(*find_vq)(struct virtio_device *vdev,
bool (*callback)(struct virtqueue *));
unsigned index,
void (*callback)(struct virtqueue *));
void (*del_vq)(struct virtqueue *vq);
};
/**
* virtio_config_val - get a single virtio config and mark it used.
* @config: the virtio config space
* @type: the type to search for.
* virtio_config_val - look for a feature and get a single virtio config.
* @vdev: the virtio device
* @fbit: the feature bit
* @offset: the type to search for.
* @val: a pointer to the value to fill in.
*
* Once used, the config type is marked with VIRTIO_CONFIG_F_USED so it can't
* be found again. This version does endian conversion. */
#define virtio_config_val(vdev, type, v) ({ \
int _err = __virtio_config_val((vdev),(type),(v),sizeof(*(v))); \
\
BUILD_BUG_ON(sizeof(*(v)) != 1 && sizeof(*(v)) != 2 \
&& sizeof(*(v)) != 4 && sizeof(*(v)) != 8); \
if (!_err) { \
switch (sizeof(*(v))) { \
case 2: le16_to_cpus((__u16 *) v); break; \
case 4: le32_to_cpus((__u32 *) v); break; \
case 8: le64_to_cpus((__u64 *) v); break; \
} \
} \
* The return value is -ENOENT if the feature doesn't exist. Otherwise
* the value is endian-corrected and returned in v. */
#define virtio_config_val(vdev, fbit, offset, v) ({ \
int _err; \
if ((vdev)->config->feature((vdev), (fbit))) { \
__virtio_config_val((vdev), (offset), (v)); \
_err = 0; \
} else \
_err = -ENOENT; \
_err; \
})
int __virtio_config_val(struct virtio_device *dev,
u8 type, void *val, size_t size);
/**
* virtio_use_bit - helper to use a feature bit in a bitfield value.
* @dev: the virtio device
* @token: the token as returned from vdev->config->find().
* @len: the length of the field.
* @bitnum: the bit to test.
* __virtio_config_val - get a single virtio config without feature check.
* @vdev: the virtio device
* @offset: the type to search for.
* @val: a pointer to the value to fill in.
*
* If handed a NULL token, it returns false, otherwise returns bit status.
* If it's one, it sets the mirroring acknowledgement bit. */
int virtio_use_bit(struct virtio_device *vdev,
void *token, unsigned int len, unsigned int bitnum);
* The value is endian-corrected and returned in v. */
#define __virtio_config_val(vdev, offset, v) do { \
BUILD_BUG_ON(sizeof(*(v)) != 1 && sizeof(*(v)) != 2 \
&& sizeof(*(v)) != 4 && sizeof(*(v)) != 8); \
(vdev)->config->get((vdev), (offset), (v), sizeof(*(v))); \
switch (sizeof(*(v))) { \
case 2: le16_to_cpus((__u16 *) v); break; \
case 4: le32_to_cpus((__u32 *) v); break; \
case 8: le64_to_cpus((__u64 *) v); break; \
} \
} while(0)
#endif /* __KERNEL__ */
#endif /* _LINUX_VIRTIO_CONFIG_H */

32
include/linux/virtio_net.h
View File

@ -5,32 +5,32 @@
/* The ID for virtio_net */
#define VIRTIO_ID_NET 1
/* The bitmap of config for virtio net */
#define VIRTIO_CONFIG_NET_F 0x40
#define VIRTIO_NET_F_NO_CSUM 0
#define VIRTIO_NET_F_TSO4 1
#define VIRTIO_NET_F_UFO 2
#define VIRTIO_NET_F_TSO4_ECN 3
#define VIRTIO_NET_F_TSO6 4
/* The feature bitmap for virtio net */
#define VIRTIO_NET_F_CSUM 0 /* Can handle pkts w/ partial csum */
#define VIRTIO_NET_F_MAC 5 /* Host has given MAC address. */
#define VIRTIO_NET_F_GSO 6 /* Can handle pkts w/ any GSO type */
/* The config defining mac address. */
#define VIRTIO_CONFIG_NET_MAC_F 0x41
struct virtio_net_config
{
/* The config defining mac address (if VIRTIO_NET_F_MAC) */
__u8 mac[6];
} __attribute__((packed));
/* This is the first element of the scatter-gather list. If you don't
* specify GSO or CSUM features, you can simply ignore the header. */
struct virtio_net_hdr
{
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 // Use csum_start, csum_offset
__u8 flags;
__u8 flags;
#define VIRTIO_NET_HDR_GSO_NONE 0 // Not a GSO frame
#define VIRTIO_NET_HDR_GSO_TCPV4 1 // GSO frame, IPv4 TCP (TSO)
/* FIXME: Do we need this? If they said they can handle ECN, do they care? */
#define VIRTIO_NET_HDR_GSO_TCPV4_ECN 2 // GSO frame, IPv4 TCP w/ ECN
#define VIRTIO_NET_HDR_GSO_UDP 3 // GSO frame, IPv4 UDP (UFO)
#define VIRTIO_NET_HDR_GSO_TCPV6 4 // GSO frame, IPv6 TCP
__u8 gso_type;
__u16 gso_size;
__u16 csum_start;
__u16 csum_offset;
#define VIRTIO_NET_HDR_GSO_ECN 0x80 // TCP has ECN set
__u8 gso_type;
__u16 hdr_len; /* Ethernet + IP + tcp/udp hdrs */
__u16 gso_size; /* Bytes to append to gso_hdr_len per frame */
__u16 csum_start; /* Position to start checksumming from */
__u16 csum_offset; /* Offset after that to place checksum */
};
#endif /* _LINUX_VIRTIO_NET_H */

57
include/linux/virtio_pci.h Normal file
View File

@ -0,0 +1,57 @@
/*
* 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.
*
*/
#ifndef _LINUX_VIRTIO_PCI_H
#define _LINUX_VIRTIO_PCI_H
#include <linux/virtio_config.h>
/* A 32-bit r/o bitmask of the features supported by the host */
#define VIRTIO_PCI_HOST_FEATURES 0
/* A 32-bit r/w bitmask of features activated by the guest */
#define VIRTIO_PCI_GUEST_FEATURES 4
/* A 32-bit r/w PFN for the currently selected queue */
#define VIRTIO_PCI_QUEUE_PFN 8
/* A 16-bit r/o queue size for the currently selected queue */
#define VIRTIO_PCI_QUEUE_NUM 12
/* A 16-bit r/w queue selector */
#define VIRTIO_PCI_QUEUE_SEL 14
/* A 16-bit r/w queue notifier */
#define VIRTIO_PCI_QUEUE_NOTIFY 16
/* An 8-bit device status register. */
#define VIRTIO_PCI_STATUS 18
/* An 8-bit r/o interrupt status register. Reading the value will return the
* current contents of the ISR and will also clear it. This is effectively
* a read-and-acknowledge. */
#define VIRTIO_PCI_ISR 19
/* The bit of the ISR which indicates a device configuration change. */
#define VIRTIO_PCI_ISR_CONFIG 0x2
/* The remaining space is defined by each driver as the per-driver
* configuration space */
#define VIRTIO_PCI_CONFIG 20
/* Virtio ABI version, this must match exactly */
#define VIRTIO_PCI_ABI_VERSION 0
#endif

14
include/linux/virtio_ring.h
View File

@ -15,9 +15,13 @@
/* This marks a buffer as write-only (otherwise read-only). */
#define VRING_DESC_F_WRITE 2
/* This means don't notify other side when buffer added. */
/* The Host uses this in used->flags to advise the Guest: don't kick me when
* you add a buffer. It's unreliable, so it's simply an optimization. Guest
* will still kick if it's out of buffers. */
#define VRING_USED_F_NO_NOTIFY 1
/* This means don't interrupt guest when buffer consumed. */
/* The Guest uses this in avail->flags to advise the Host: don't interrupt me
* when you consume a buffer. It's unreliable, so it's simply an
* optimization. */
#define VRING_AVAIL_F_NO_INTERRUPT 1
/* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
@ -89,7 +93,7 @@ struct vring {
* };
*/
static inline void vring_init(struct vring *vr, unsigned int num, void *p,
unsigned int pagesize)
unsigned long pagesize)
{
vr->num = num;
vr->desc = p;
@ -98,7 +102,7 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p,
& ~(pagesize - 1));
}
static inline unsigned vring_size(unsigned int num, unsigned int pagesize)
static inline unsigned vring_size(unsigned int num, unsigned long pagesize)
{
return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (2 + num)
+ pagesize - 1) & ~(pagesize - 1))
@ -114,7 +118,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *vq),
bool (*callback)(struct virtqueue *vq));
void (*callback)(struct virtqueue *vq));
void vring_del_virtqueue(struct virtqueue *vq);
irqreturn_t vring_interrupt(int irq, void *_vq);

8
net/9p/trans_virtio.c
View File

@ -199,14 +199,12 @@ static void p9_virtio_close(struct p9_trans *trans)
kfree(trans);
}
static bool p9_virtio_intr(struct virtqueue *q)
static void p9_virtio_intr(struct virtqueue *q)
{
struct virtio_chan *chan = q->vdev->priv;
P9_DPRINTK(P9_DEBUG_TRANS, "9p poll_wakeup: %p\n", &chan->wq);
wake_up_interruptible(&chan->wq);
return true;
}
static int p9_virtio_probe(struct virtio_device *dev)
@ -236,13 +234,13 @@ static int p9_virtio_probe(struct virtio_device *dev)
/* Find the input queue. */
dev->priv = chan;
chan->in_vq = dev->config->find_vq(dev, p9_virtio_intr);
chan->in_vq = dev->config->find_vq(dev, 0, p9_virtio_intr);
if (IS_ERR(chan->in_vq)) {
err = PTR_ERR(chan->in_vq);
goto free;
}
chan->out_vq = dev->config->find_vq(dev, NULL);
chan->out_vq = dev->config->find_vq(dev, 1, NULL);
if (IS_ERR(chan->out_vq)) {
err = PTR_ERR(chan->out_vq);
goto free_in_vq;

29
net/core/skbuff.c
View File

@ -2461,6 +2461,34 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
return elt;
}
/**
* skb_partial_csum_set - set up and verify partial csum values for packet
* @skb: the skb to set
* @start: the number of bytes after skb->data to start checksumming.
* @off: the offset from start to place the checksum.
*
* For untrusted partially-checksummed packets, we need to make sure the values
* for skb->csum_start and skb->csum_offset are valid so we don't oops.
*
* This function checks and sets those values and skb->ip_summed: if this
* returns false you should drop the packet.
*/
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off)
{
if (unlikely(start > skb->len - 2) ||
unlikely((int)start + off > skb->len - 2)) {
if (net_ratelimit())
printk(KERN_WARNING
"bad partial csum: csum=%u/%u len=%u\n",
start, off, skb->len);
return false;
}
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = skb_headroom(skb) + start;
skb->csum_offset = off;
return true;
}
EXPORT_SYMBOL(___pskb_trim);
EXPORT_SYMBOL(__kfree_skb);
EXPORT_SYMBOL(kfree_skb);
@ -2497,3 +2525,4 @@ EXPORT_SYMBOL(skb_append_datato_frags);
EXPORT_SYMBOL_GPL(skb_to_sgvec);
EXPORT_SYMBOL_GPL(skb_cow_data);
EXPORT_SYMBOL_GPL(skb_partial_csum_set);