qemu/hw/9pfs/virtio-9p-device.c
Aneesh Kumar K.V e9a0152ba1 hw/9pfs: use migration blockers to prevent live migration when virtfs export path is mounted
Now when you try to migrate with VirtFS export path mounted, you get a proper QMP error:

(qemu) migrate tcp:localhost:4444
Migration is disabled when VirtFS export path '/tmp/' is mounted in the guest using mount_tag 'v_tmp'
(qemu)

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-12-04 22:35:28 +05:30

189 lines
5.6 KiB
C

/*
* Virtio 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "hw/virtio.h"
#include "hw/pc.h"
#include "qemu_socket.h"
#include "hw/virtio-pci.h"
#include "virtio-9p.h"
#include "fsdev/qemu-fsdev.h"
#include "virtio-9p-xattr.h"
#include "virtio-9p-coth.h"
static uint32_t virtio_9p_get_features(VirtIODevice *vdev, uint32_t features)
{
features |= 1 << VIRTIO_9P_MOUNT_TAG;
return features;
}
static V9fsState *to_virtio_9p(VirtIODevice *vdev)
{
return (V9fsState *)vdev;
}
static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
{
int len;
struct virtio_9p_config *cfg;
V9fsState *s = to_virtio_9p(vdev);
len = strlen(s->tag);
cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
stw_raw(&cfg->tag_len, len);
/* We don't copy the terminating null to config space */
memcpy(cfg->tag, s->tag, len);
memcpy(config, cfg, s->config_size);
g_free(cfg);
}
VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
{
V9fsState *s;
int i, len;
struct stat stat;
FsDriverEntry *fse;
V9fsPath path;
s = (V9fsState *)virtio_common_init("virtio-9p",
VIRTIO_ID_9P,
sizeof(struct virtio_9p_config)+
MAX_TAG_LEN,
sizeof(V9fsState));
/* initialize pdu allocator */
QLIST_INIT(&s->free_list);
QLIST_INIT(&s->active_list);
for (i = 0; i < (MAX_REQ - 1); i++) {
QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
}
s->vq = virtio_add_queue(&s->vdev, MAX_REQ, handle_9p_output);
fse = get_fsdev_fsentry(conf->fsdev_id);
if (!fse) {
/* We don't have a fsdev identified by fsdev_id */
fprintf(stderr, "Virtio-9p device couldn't find fsdev with the "
"id = %s\n", conf->fsdev_id ? conf->fsdev_id : "NULL");
exit(1);
}
if (!fse->path || !conf->tag) {
/* we haven't specified a mount_tag or the path */
fprintf(stderr, "fsdev with id %s needs path "
"and Virtio-9p device needs mount_tag arguments\n",
conf->fsdev_id);
exit(1);
}
s->ctx.export_flags = fse->export_flags;
s->ctx.fs_root = g_strdup(fse->path);
s->ctx.exops.get_st_gen = NULL;
if (fse->export_flags & V9FS_SM_PASSTHROUGH) {
s->ctx.xops = passthrough_xattr_ops;
} else if (fse->export_flags & V9FS_SM_MAPPED) {
s->ctx.xops = mapped_xattr_ops;
} else if (fse->export_flags & V9FS_SM_NONE) {
s->ctx.xops = none_xattr_ops;
}
len = strlen(conf->tag);
if (len > MAX_TAG_LEN - 1) {
fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
"maximum (%d bytes)", conf->tag, len, MAX_TAG_LEN - 1);
exit(1);
}
s->tag = strdup(conf->tag);
s->ctx.uid = -1;
s->ops = fse->ops;
s->vdev.get_features = virtio_9p_get_features;
s->config_size = sizeof(struct virtio_9p_config) + len;
s->vdev.get_config = virtio_9p_get_config;
s->fid_list = NULL;
qemu_co_rwlock_init(&s->rename_lock);
if (s->ops->init(&s->ctx) < 0) {
fprintf(stderr, "Virtio-9p Failed to initialize fs-driver with id:%s"
" and export path:%s\n", conf->fsdev_id, s->ctx.fs_root);
exit(1);
}
if (v9fs_init_worker_threads() < 0) {
fprintf(stderr, "worker thread initialization failed\n");
exit(1);
}
/*
* Check details of export path, We need to use fs driver
* call back to do that. Since we are in the init path, we don't
* use co-routines here.
*/
v9fs_path_init(&path);
if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
fprintf(stderr,
"error in converting name to path %s", strerror(errno));
exit(1);
}
if (s->ops->lstat(&s->ctx, &path, &stat)) {
fprintf(stderr, "share path %s does not exist\n", fse->path);
exit(1);
} else if (!S_ISDIR(stat.st_mode)) {
fprintf(stderr, "share path %s is not a directory\n", fse->path);
exit(1);
}
v9fs_path_free(&path);
return &s->vdev;
}
static int virtio_9p_init_pci(PCIDevice *pci_dev)
{
VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
VirtIODevice *vdev;
vdev = virtio_9p_init(&pci_dev->qdev, &proxy->fsconf);
vdev->nvectors = proxy->nvectors;
virtio_init_pci(proxy, vdev);
/* make the actual value visible */
proxy->nvectors = vdev->nvectors;
return 0;
}
static PCIDeviceInfo virtio_9p_info = {
.qdev.name = "virtio-9p-pci",
.qdev.size = sizeof(VirtIOPCIProxy),
.init = virtio_9p_init_pci,
.vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET,
.device_id = 0x1009,
.revision = VIRTIO_PCI_ABI_VERSION,
.class_id = 0x2,
.qdev.props = (Property[]) {
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
DEFINE_PROP_STRING("mount_tag", VirtIOPCIProxy, fsconf.tag),
DEFINE_PROP_STRING("fsdev", VirtIOPCIProxy, fsconf.fsdev_id),
DEFINE_PROP_END_OF_LIST(),
}
};
static void virtio_9p_register_devices(void)
{
pci_qdev_register(&virtio_9p_info);
virtio_9p_set_fd_limit();
}
device_init(virtio_9p_register_devices)