Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus (93890b71) · Commits · e / devices / android_kernel_samsung_universal8895

Documentation/lguest/lguest.c

+154 −77

Original line number	Original line	Diff line number	Diff line
	@@ -34,6 +34,8 @@
	#include <zlib.h>		#include <zlib.h>
	#include <assert.h>		#include <assert.h>
	#include <sched.h>		#include <sched.h>
			#include <limits.h>
			#include <stddef.h>
	#include "linux/lguest_launcher.h"		#include "linux/lguest_launcher.h"
	#include "linux/virtio_config.h"		#include "linux/virtio_config.h"
	#include "linux/virtio_net.h"		#include "linux/virtio_net.h"
	@@ -99,13 +101,11 @@ struct device_list
	/* The descriptor page for the devices. */		/* The descriptor page for the devices. */
	u8 *descpage;		u8 *descpage;

	/* The tail of the last descriptor. */
	unsigned int desc_used;

	/* A single linked list of devices. */		/* A single linked list of devices. */
	struct device *dev;		struct device *dev;
	/* ... And an end pointer so we can easily append new devices */		/* And a pointer to the last device for easy append and also for
	struct device **lastdev;		* configuration appending. */
			struct device *lastdev;
	};		};

	/* The list of Guest devices, based on command line arguments. */		/* 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 cpu_to_le64(v64) (v64)
	#define le16_to_cpu(v16) (v16)		#define le16_to_cpu(v16) (v16)
	#define le32_to_cpu(v32) (v32)		#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		/*L:100 The Launcher code itself takes us out into userspace, that scary place
	* where pointers run wild and free! Unfortunately, like most userspace		* where pointers run wild and free! Unfortunately, like most userspace
	@@ -914,23 +921,60 @@ static void enable_fd(int fd, struct virtqueue *vq)
	write(waker_fd, &vq->dev->fd, sizeof(vq->dev->fd));		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. */		/* This is the generic routine we call when the Guest uses LHCALL_NOTIFY. */
	static void handle_output(int fd, unsigned long addr)		static void handle_output(int fd, unsigned long addr)
	{		{
	struct device *i;		struct device *i;
	struct virtqueue *vq;		struct virtqueue *vq;

	/* Check each virtqueue. */		/* Check each device and virtqueue. */
	for (i = devices.dev; i; i = i->next) {		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) {		for (vq = i->vq; vq; vq = vq->next) {
	if (vq->config.pfn == addr/getpagesize()		if (vq->config.pfn != addr/getpagesize())
	&& vq->handle_output) {		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);		verbose("Output to %s\n", vq->dev->name);
			if (vq->handle_output)
	vq->handle_output(fd, vq);		vq->handle_output(fd, vq);
	return;		return;
	}		}
	}		}
	}

	/* Early console write is done using notify on a nul-terminated string		/* Early console write is done using notify on a nul-terminated string
	* in Guest memory. */		* in Guest memory. */
	@@ -986,54 +1030,44 @@ static void handle_input(int fd)
	*		*
	* All devices need a descriptor so the Guest knows it exists, and a "struct		* 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		* device" so the Launcher can keep track of it. We have common helper
	* routines to allocate them.		* routines to allocate and manage 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. */
	static struct lguest_device_desc *new_dev_desc(u16 type)
	{
	struct lguest_device_desc *d;

	/* We only have one page for all the descriptors. */
	if (devices.desc_used + sizeof(*d) > getpagesize())
	errx(1, "Too many devices");

	/* We don't need to set config_len or status: page is 0 already. */		/* The layout of the device page is a "struct lguest_device_desc" followed by a
	d = (void *)devices.descpage + devices.desc_used;		* number of virtqueue descriptors, then two sets of feature bits, then an
	d->type = type;		* array of configuration bytes. This routine returns the configuration
	devices.desc_used += sizeof(*d);		* pointer. */
			static u8 device_config(const struct device dev)
	return d;		{
			return (void *)(dev->desc + 1)
			+ dev->desc->num_vq * sizeof(struct lguest_vqconfig)
			+ dev->desc->feature_len * 2;
	}		}

	/* Each device descriptor is followed by some configuration information.		/* This routine allocates a new "struct lguest_device_desc" from descriptor
	* Each configuration field looks like: u8 type, u8 len, [... len bytes...].		* table page just above the Guest's normal memory. It returns a pointer to
	*		* that descriptor. */
	* This routine adds a new field to an existing device's descriptor. It only		static struct lguest_device_desc *new_dev_desc(u16 type)
	* 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? */		struct lguest_device_desc d = { .type = type };
	assert(devices.descpage + devices.desc_used		void *p;
	== (u8 *)(dev->desc + 1) + dev->desc->config_len);

	/* We only have one page of device descriptions. */		/* Figure out where the next device config is, based on the last one. */
	if (devices.desc_used + 2 + len > getpagesize())		if (devices.lastdev)
	errx(1, "Too many devices");		p = device_config(devices.lastdev)
			+ devices.lastdev->desc->config_len;
			else
			p = devices.descpage;

	/* Copy in the new config header: type then length. */		/* We only have one page for all the descriptors. */
	devices.descpage[devices.desc_used++] = type;		if (p + sizeof(d) > (void *)devices.descpage + getpagesize())
	devices.descpage[devices.desc_used++] = len;		errx(1, "Too many devices");
	memcpy(devices.descpage + devices.desc_used, c, len);
	devices.desc_used += len;

	/* Update the device descriptor length: two byte head then data. */		/* p might not be aligned, so we memcpy in. */
	dev->desc->config_len += 2 + len;		return memcpy(p, &d, sizeof(d));
	}		}

	/* This routine adds a virtqueue to a device. We specify how many descriptors		/* Each device descriptor is followed by the description of its virtqueues. We
	* the virtqueue is to have. */		* specify how many descriptors the virtqueue is to have. */
	static void add_virtqueue(struct device *dev, unsigned int num_descs,		static void add_virtqueue(struct device *dev, unsigned int num_descs,
	void (handle_output)(int fd, struct virtqueue me))		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. */		/* Initialize the vring. */
	vring_init(&vq->vring, num_descs, p, getpagesize());		vring_init(&vq->vring, num_descs, p, getpagesize());

	/* Add the configuration information to this device's descriptor. */		/* Append virtqueue to this device's descriptor. We use
	add_desc_field(dev, VIRTIO_CONFIG_F_VIRTQUEUE,		* device_config() to get the end of the device's current virtqueues;
	sizeof(vq->config), &vq->config);		* 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		/* Add to tail of list, so dev->vq is first vq, dev->vq->next is
	* second. */		* second. */
	@@ -1072,11 +1112,41 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
	* virtqueue. */		* virtqueue. */
	vq->handle_output = handle_output;		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)		if (!handle_output)
	vq->vring.used->flags = VRING_USED_F_NO_NOTIFY;		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		/* This routine does all the creation and setup of a new device, including
	* calling new_dev_desc() to allocate the descriptor and device memory. */		* calling new_dev_desc() to allocate the descriptor and device memory. */
	static struct device new_device(const char name, u16 type, int fd,		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));		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. */		/* Now we populate the fields one at a time. */
	dev->fd = fd;		dev->fd = fd;
	/* If we have an input handler for this file descriptor, then we add it		/* 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->handle_input = handle_input;
	dev->name = name;		dev->name = name;
	dev->vq = NULL;		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;		return dev;
	}		}

	@@ -1226,7 +1299,7 @@ static void setup_tun_net(const char *arg)
	int netfd, ipfd;		int netfd, ipfd;
	u32 ip;		u32 ip;
	const char *br_name = NULL;		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		/* 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		* 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);		ip = str2ip(arg);

	/* Set up the tun device, and get the mac address for the interface. */		/* 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. */		/* 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);		close(ipfd);

	verbose("device %u: tun net %u.%u.%u.%u\n",		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 device *dev;
	struct vblk_info *vblk;		struct vblk_info *vblk;
	void *stack;		void *stack;
	u64 cap;		struct virtio_blk_config conf;
	unsigned int val;

	/* This is the pipe the I/O thread will use to tell us I/O is done. */		/* This is the pipe the I/O thread will use to tell us I/O is done. */
	pipe(p);		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->fd = open_or_die(filename, O_RDWR\|O_LARGEFILE);
	vblk->len = lseek64(vblk->fd, 0, SEEK_END);		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. */		/* Tell Guest how many sectors this device has. */
	cap = cpu_to_le64(vblk->len / 512);		conf.capacity = cpu_to_le64(vblk->len / 512);
	add_desc_field(dev, VIRTIO_CONFIG_BLK_F_CAPACITY, sizeof(cap), &cap);

	/* Tell Guest not to put in too many descriptors at once: two are used		/* Tell Guest not to put in too many descriptors at once: two are used
	* for the in and out elements. */		* for the in and out elements. */
	val = cpu_to_le32(VIRTQUEUE_NUM - 2);		add_feature(dev, VIRTIO_BLK_F_SEG_MAX);
	add_desc_field(dev, VIRTIO_CONFIG_BLK_F_SEG_MAX, sizeof(val), &val);		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. */		/* The I/O thread writes to this end of the pipe when done. */
	vblk->done_fd = p[1];		vblk->done_fd = p[1];
	@@ -1505,7 +1582,7 @@ static void setup_block_file(const char *filename)
	close(vblk->workpipe[0]);		close(vblk->workpipe[0]);

	verbose("device %u: virtblock %llu sectors\n",		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. :*/		/* 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		/* First we initialize the device list. Since console and network
	* device receive input from a file descriptor, we keep an fdset		* device receive input from a file descriptor, we keep an fdset
	* (infds) and the maximum fd number (max_infd) with the head of the		* (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		* list. We also keep a pointer to the last device. Finally, we keep
	* to the list. Finally, we keep the next interrupt number to hand out		* the next interrupt number to hand out (1: remember that 0 is used by
	* (1: remember that 0 is used by the timer). */		* the timer). */
	FD_ZERO(&devices.infds);		FD_ZERO(&devices.infds);
	devices.max_infd = -1;		devices.max_infd = -1;
	devices.lastdev = &devices.dev;		devices.lastdev = NULL;
	devices.next_irq = 1;		devices.next_irq = 1;

	cpu_id = 0;		cpu_id = 0;

arch/x86/kvm/Kconfig

+1 −0

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

	endif # VIRTUALIZATION		endif # VIRTUALIZATION

drivers/Kconfig

+0 −2

Original line number	Original line	Diff line number	Diff line
	@@ -91,6 +91,4 @@ source "drivers/dca/Kconfig"
	source "drivers/auxdisplay/Kconfig"		source "drivers/auxdisplay/Kconfig"

	source "drivers/uio/Kconfig"		source "drivers/uio/Kconfig"

	source "drivers/virtio/Kconfig"
	endmenu		endmenu

drivers/block/Kconfig

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -440,6 +440,7 @@ config VIRTIO_BLK
	tristate "Virtio block driver (EXPERIMENTAL)"		tristate "Virtio block driver (EXPERIMENTAL)"
	depends on EXPERIMENTAL && VIRTIO		depends on EXPERIMENTAL && VIRTIO
	---help---		---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		endif # BLK_DEV

drivers/block/virtio_blk.c

+65 −41

Original line number	Original line	Diff line number	Diff line
	@@ -7,8 +7,10 @@
	#include <linux/scatterlist.h>		#include <linux/scatterlist.h>

	#define VIRTIO_MAX_SG (3+MAX_PHYS_SEGMENTS)		#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		struct virtio_blk
	{		{
	spinlock_t lock;		spinlock_t lock;
	@@ -36,7 +38,7 @@ struct virtblk_req
	struct virtio_blk_inhdr in_hdr;		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 virtio_blk *vblk = vq->vdev->priv;
	struct virtblk_req *vbr;		struct virtblk_req *vbr;
	@@ -65,7 +67,6 @@ static bool blk_done(struct virtqueue *vq)
	/* In case queue is stopped waiting for more buffers. */		/* In case queue is stopped waiting for more buffers. */
	blk_start_queue(vblk->disk->queue);		blk_start_queue(vblk->disk->queue);
	spin_unlock_irqrestore(&vblk->lock, flags);		spin_unlock_irqrestore(&vblk->lock, flags);
	return true;
	}		}

	static bool do_req(struct request_queue q, struct virtio_blk vblk,		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);		(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 = {		static struct block_device_operations virtblk_fops = {
	.ioctl = virtblk_ioctl,		.ioctl = virtblk_ioctl,
	.owner = THIS_MODULE,		.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)		static int virtblk_probe(struct virtio_device *vdev)
	{		{
	struct virtio_blk *vblk;		struct virtio_blk *vblk;
	int err, major;		int err;
	void *token;
	unsigned int len;
	u64 cap;		u64 cap;
	u32 v;		u32 v;

			if (index_to_minor(index) >= 1 << MINORBITS)
			return -ENOSPC;

	vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);		vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
	if (!vblk) {		if (!vblk) {
	err = -ENOMEM;		err = -ENOMEM;
	@@ -178,7 +196,7 @@ static int virtblk_probe(struct virtio_device *vdev)
	vblk->vdev = vdev;		vblk->vdev = vdev;

	/* We expect one virtqueue, for output. */		/* 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)) {		if (IS_ERR(vblk->vq)) {
	err = PTR_ERR(vblk->vq);		err = PTR_ERR(vblk->vq);
	goto out_free_vblk;		goto out_free_vblk;
	@@ -190,17 +208,11 @@ static int virtblk_probe(struct virtio_device *vdev)
	goto out_free_vq;		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? */		/* 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) {		if (!vblk->disk) {
	err = -ENOMEM;		err = -ENOMEM;
	goto out_unregister_blkdev;		goto out_mempool;
	}		}

	vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);		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;		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->major = major;
	vblk->disk->first_minor = 0;		vblk->disk->first_minor = index_to_minor(index);
	vblk->disk->private_data = vblk;		vblk->disk->private_data = vblk;
	vblk->disk->fops = &virtblk_fops;		vblk->disk->fops = &virtblk_fops;
			index++;

	/* If barriers are supported, tell block layer that queue is ordered */		/* If barriers are supported, tell block layer that queue is ordered */
	token = vdev->config->find(vdev, VIRTIO_CONFIG_BLK_F, &len);		if (vdev->config->feature(vdev, VIRTIO_BLK_F_BARRIER))
	if (virtio_use_bit(vdev, token, len, VIRTIO_BLK_F_BARRIER))
	blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);		blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);

	err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_CAPACITY, &cap);		/* Host must always specify the capacity. */
	if (err) {		__virtio_config_val(vdev, offsetof(struct virtio_blk_config, capacity),
	dev_err(&vdev->dev, "Bad/missing capacity in config\n");		&cap);
	goto out_cleanup_queue;
	}

	/* If capacity is too big, truncate with warning. */		/* If capacity is too big, truncate with warning. */
	if ((sector_t)cap != cap) {		if ((sector_t)cap != cap) {
	@@ -234,31 +256,25 @@ static int virtblk_probe(struct virtio_device *vdev)
	}		}
	set_capacity(vblk->disk, cap);		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)		if (!err)
	blk_queue_max_segment_size(vblk->disk->queue, v);		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)		if (!err)
	blk_queue_max_hw_segments(vblk->disk->queue, v);		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);		add_disk(vblk->disk);
	return 0;		return 0;

	out_cleanup_queue:
	blk_cleanup_queue(vblk->disk->queue);
	out_put_disk:		out_put_disk:
	put_disk(vblk->disk);		put_disk(vblk->disk);
	out_unregister_blkdev:
	unregister_blkdev(major, "virtblk");
	out_mempool:		out_mempool:
	mempool_destroy(vblk->pool);		mempool_destroy(vblk->pool);
	out_free_vq:		out_free_vq:
	@@ -274,12 +290,16 @@ static void virtblk_remove(struct virtio_device *vdev)
	struct virtio_blk *vblk = vdev->priv;		struct virtio_blk *vblk = vdev->priv;
	int major = vblk->disk->major;		int major = vblk->disk->major;

			/* Nothing should be pending. */
	BUG_ON(!list_empty(&vblk->reqs));		BUG_ON(!list_empty(&vblk->reqs));

			/* Stop all the virtqueues. */
			vdev->config->reset(vdev);

	blk_cleanup_queue(vblk->disk->queue);		blk_cleanup_queue(vblk->disk->queue);
	put_disk(vblk->disk);		put_disk(vblk->disk);
	unregister_blkdev(major, "virtblk");		unregister_blkdev(major, "virtblk");
	mempool_destroy(vblk->pool);		mempool_destroy(vblk->pool);
	/* There should be nothing in the queue now, so no need to shutdown */
	vdev->config->del_vq(vblk->vq);		vdev->config->del_vq(vblk->vq);
	kfree(vblk);		kfree(vblk);
	}		}
	@@ -299,11 +319,15 @@ static struct virtio_driver virtio_blk = {

	static int __init init(void)		static int __init init(void)
	{		{
			major = register_blkdev(0, "virtblk");
			if (major < 0)
			return major;
	return register_virtio_driver(&virtio_blk);		return register_virtio_driver(&virtio_blk);
	}		}

	static void __exit fini(void)		static void __exit fini(void)
	{		{
			unregister_blkdev(major, "virtblk");
	unregister_virtio_driver(&virtio_blk);		unregister_virtio_driver(&virtio_blk);
	}		}
	module_init(init);		module_init(init);