qemu/fsdev/qemu-fsdev.c
Aneesh Kumar K.V 9db221ae73 hw/9pfs: Add synthetic file system support using 9p
This patch create a synthetic file system with mount tag
v_synth when -virtfs_synth command line option is specified
in qemu. The synthetic file system can be mounted in guest
using 9p using the below command line

mount -t 9p -oversion=9p2000.L,trans=virtio v_synth  <mountpint>

Synthetic file system enabled different qemu subsystem to register
callbacks for read and write events from guest. The subsystem
can create directories and files in the synthetic file system as show
in ex below

    qemu_v9fs_synth_mkdir(NULL, 0777, "test2", &node);
    qemu_v9fs_synth_add_file(node, 0777, "testfile",
                             my_test_read, NULL, NULL);

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-10-31 12:34:18 +05:30

137 lines
3.6 KiB
C

/*
* Virtio 9p
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Gautham R Shenoy <ego@in.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 <stdio.h>
#include <string.h>
#include "qemu-fsdev.h"
#include "qemu-queue.h"
#include "osdep.h"
#include "qemu-common.h"
#include "qemu-config.h"
static QTAILQ_HEAD(FsDriverEntry_head, FsDriverListEntry) fsdriver_entries =
QTAILQ_HEAD_INITIALIZER(fsdriver_entries);
static FsDriverTable FsDrivers[] = {
{ .name = "local", .ops = &local_ops},
{ .name = "handle", .ops = &handle_ops},
{ .name = "synth", .ops = &synth_ops},
};
int qemu_fsdev_add(QemuOpts *opts)
{
struct FsDriverListEntry *fsle;
int i;
const char *fsdev_id = qemu_opts_id(opts);
const char *fsdriver = qemu_opt_get(opts, "fsdriver");
const char *path = qemu_opt_get(opts, "path");
const char *sec_model = qemu_opt_get(opts, "security_model");
const char *writeout = qemu_opt_get(opts, "writeout");
bool ro = qemu_opt_get_bool(opts, "readonly", 0);
if (!fsdev_id) {
fprintf(stderr, "fsdev: No id specified\n");
return -1;
}
if (fsdriver) {
for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
break;
}
}
if (i == ARRAY_SIZE(FsDrivers)) {
fprintf(stderr, "fsdev: fsdriver %s not found\n", fsdriver);
return -1;
}
} else {
fprintf(stderr, "fsdev: No fsdriver specified\n");
return -1;
}
if (!strcmp(fsdriver, "local") && !sec_model) {
fprintf(stderr, "security model not specified, "
"local fs needs security model\nvalid options are:"
"\tsecurity_model=[passthrough|mapped|none]\n");
return -1;
}
if (strcmp(fsdriver, "local") && sec_model) {
fprintf(stderr, "only local fs driver needs security model\n");
return -1;
}
if (!path) {
fprintf(stderr, "fsdev: No path specified.\n");
return -1;
}
fsle = g_malloc(sizeof(*fsle));
fsle->fse.fsdev_id = g_strdup(fsdev_id);
fsle->fse.path = g_strdup(path);
fsle->fse.ops = FsDrivers[i].ops;
fsle->fse.export_flags = 0;
if (writeout) {
if (!strcmp(writeout, "immediate")) {
fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
}
}
if (ro) {
fsle->fse.export_flags |= V9FS_RDONLY;
} else {
fsle->fse.export_flags &= ~V9FS_RDONLY;
}
if (strcmp(fsdriver, "local")) {
goto done;
}
if (!strcmp(sec_model, "passthrough")) {
fsle->fse.export_flags |= V9FS_SM_PASSTHROUGH;
} else if (!strcmp(sec_model, "mapped")) {
fsle->fse.export_flags |= V9FS_SM_MAPPED;
} else if (!strcmp(sec_model, "none")) {
fsle->fse.export_flags |= V9FS_SM_NONE;
} else {
fprintf(stderr, "Invalid security model %s specified, valid options are"
"\n\t [passthrough|mapped|none]\n", sec_model);
return -1;
}
done:
QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
return 0;
}
FsDriverEntry *get_fsdev_fsentry(char *id)
{
if (id) {
struct FsDriverListEntry *fsle;
QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
if (strcmp(fsle->fse.fsdev_id, id) == 0) {
return &fsle->fse;
}
}
}
return NULL;
}
static void fsdev_register_config(void)
{
qemu_add_opts(&qemu_fsdev_opts);
qemu_add_opts(&qemu_virtfs_opts);
}
machine_init(fsdev_register_config);