This patch adds support for specifying the backend (tapdisk or ioemu)
to blktapctrl. Images can be specified e.g. as tap:tapdisk:aio,
tap:ioemu:qcow2 or tap:vmdk. When omitting the backend, a default is
chosen based on the image type (currently always tapdisk because ioemu
as a backend is broken until a follow-up patch series against qemu-xen
is applied)
Signed-off-by: Kevin Wolf <kwolf@xxxxxxx>
blktapctrl: Select backend by prefix
This patch adds support for specifying the backend (tapdisk or ioemu)
to blktapctrl. Images can be specified e.g. as tap:tapdisk:aio,
tap:ioemu:qcow2 or tap:vmdk. When omitting the backend, a default is
chosen based on the image type (currently always tapdisk because ioemu
as a backend is broken until a follow-up patch series against qemu-xen
is applied)
Signed-off-by: Kevin Wolf <kwolf@xxxxxxx>
Index: xen-unstable.hg/tools/blktap/drivers/blktapctrl.c
===================================================================
--- xen-unstable.hg.orig/tools/blktap/drivers/blktapctrl.c
+++ xen-unstable.hg/tools/blktap/drivers/blktapctrl.c
@@ -148,7 +148,8 @@ static int get_tapdisk_pid(blkif_t *blki
* return 0 on success, -1 on error.
*/
-static int test_path(char *path, char **dev, int *type, blkif_t **blkif)
+static int test_path(char *path, char **dev, int *type, blkif_t **blkif,
+ int* use_ioemu)
{
char *ptr, handle[10];
int i, size, found = 0;
@@ -158,6 +159,17 @@ static int test_path(char *path, char **
*type = MAX_DISK_TYPES + 1;
*blkif = NULL;
+ if (!strncmp(path, "tapdisk:", strlen("tapdisk:"))) {
+ *use_ioemu = 0;
+ path += strlen("tapdisk:");
+ } else if (!strncmp(path, "ioemu:", strlen("ioemu:"))) {
+ *use_ioemu = 1;
+ path += strlen("ioemu:");
+ } else {
+ // Use the default for the image type
+ *use_ioemu = -1;
+ }
+
if ( (ptr = strstr(path, ":"))!=NULL) {
handle_len = (ptr - path);
memcpy(handle, path, handle_len);
@@ -174,6 +186,8 @@ static int test_path(char *path, char **
}
if (found) {
+ if (*use_ioemu == -1)
+ *use_ioemu = dtypes[i]->use_ioemu;
*type = dtypes[i]->idnum;
if (dtypes[i]->single_handler == 1) {
@@ -185,6 +199,7 @@ static int test_path(char *path, char **
*blkif = active_disks[dtypes[i]
->idnum]->blkif;
}
+
return 0;
}
}
@@ -504,7 +519,8 @@ static int connect_qemu(blkif_t *blkif,
static int tapdisk_ioemu_pid = 0;
static int dom0_readfd = 0;
static int dom0_writefd = 0;
-
+ int refresh_pid = 0;
+
if (asprintf(&rdctldev, BLKTAP_CTRL_DIR "/qemu-read-%d", domid) < 0)
return -1;
@@ -523,15 +539,23 @@ static int connect_qemu(blkif_t *blkif,
if (tapdisk_ioemu_pid == 0 || kill(tapdisk_ioemu_pid, 0)) {
/* No device model and tapdisk-ioemu doesn't run yet */
DPRINTF("Launching tapdisk-ioemu\n");
- tapdisk_ioemu_pid = launch_tapdisk_ioemu();
+ launch_tapdisk_ioemu();
dom0_readfd = open_ctrl_socket(wrctldev);
dom0_writefd = open_ctrl_socket(rdctldev);
+
+ refresh_pid = 1;
}
DPRINTF("Using tapdisk-ioemu connection\n");
blkif->fds[READ] = dom0_readfd;
blkif->fds[WRITE] = dom0_writefd;
+
+ if (refresh_pid) {
+ get_tapdisk_pid(blkif);
+ tapdisk_ioemu_pid = blkif->tappid;
+ }
+
} else if (access(rdctldev, R_OK | W_OK) == 0) {
/* Use existing pipe to the device model */
DPRINTF("Using qemu-dm connection\n");
@@ -605,13 +629,14 @@ static int blktapctrl_new_blkif(blkif_t
image_t *image;
blkif_t *exist = NULL;
static uint16_t next_cookie = 0;
+ int use_ioemu;
DPRINTF("Received a poll for a new vbd\n");
if ( ((blk=blkif->info) != NULL) && (blk->params != NULL) ) {
if (blktap_interface_create(ctlfd, &major, &minor, blkif) < 0)
return -1;
- if (test_path(blk->params, &ptr, &type, &exist) != 0) {
+ if (test_path(blk->params, &ptr, &type, &exist, &use_ioemu) !=
0) {
DPRINTF("Error in blktap device string(%s).\n",
blk->params);
goto fail;
@@ -620,7 +645,7 @@ static int blktapctrl_new_blkif(blkif_t
blkif->cookie = next_cookie++;
if (!exist) {
- if (type == DISK_TYPE_IOEMU) {
+ if (use_ioemu) {
if (connect_qemu(blkif, blkif->domid))
goto fail;
} else {
Index: xen-unstable.hg/tools/blktap/drivers/tapdisk.h
===================================================================
--- xen-unstable.hg.orig/tools/blktap/drivers/tapdisk.h
+++ xen-unstable.hg/tools/blktap/drivers/tapdisk.h
@@ -145,6 +145,8 @@ typedef struct disk_info {
char handle[10]; /* xend handle, e.g. 'ram' */
int single_handler; /* is there a single controller for all */
/* instances of disk type? */
+ int use_ioemu; /* backend provider: 0 = tapdisk; 1 = ioemu */
+
#ifdef TAPDISK
struct tap_disk *drv;
#endif
@@ -167,7 +169,6 @@ extern struct tap_disk tapdisk_qcow2;
#define DISK_TYPE_RAM 3
#define DISK_TYPE_QCOW 4
#define DISK_TYPE_QCOW2 5
-#define DISK_TYPE_IOEMU 6
/*Define Individual Disk Parameters here */
@@ -176,6 +177,7 @@ static disk_info_t aio_disk = {
"raw image (aio)",
"aio",
0,
+ 0,
#ifdef TAPDISK
&tapdisk_aio,
#endif
@@ -186,6 +188,7 @@ static disk_info_t sync_disk = {
"raw image (sync)",
"sync",
0,
+ 0,
#ifdef TAPDISK
&tapdisk_sync,
#endif
@@ -196,6 +199,7 @@ static disk_info_t vmdk_disk = {
"vmware image (vmdk)",
"vmdk",
1,
+ 0,
#ifdef TAPDISK
&tapdisk_vmdk,
#endif
@@ -206,6 +210,7 @@ static disk_info_t ram_disk = {
"ramdisk image (ram)",
"ram",
1,
+ 0,
#ifdef TAPDISK
&tapdisk_ram,
#endif
@@ -216,6 +221,7 @@ static disk_info_t qcow_disk = {
"qcow disk (qcow)",
"qcow",
0,
+ 0,
#ifdef TAPDISK
&tapdisk_qcow,
#endif
@@ -226,21 +232,12 @@ static disk_info_t qcow2_disk = {
"qcow2 disk (qcow2)",
"qcow2",
0,
+ 0,
#ifdef TAPDISK
&tapdisk_qcow2,
#endif
};
-static disk_info_t ioemu_disk = {
- DISK_TYPE_IOEMU,
- "ioemu disk",
- "ioemu",
- 1,
-#ifdef TAPDISK
- NULL
-#endif
-};
-
/*Main disk info array */
static disk_info_t *dtypes[] = {
&aio_disk,
@@ -249,7 +246,6 @@ static disk_info_t *dtypes[] = {
&ram_disk,
&qcow_disk,
&qcow2_disk,
- &ioemu_disk,
};
typedef struct driver_list_entry {
Index: xen-unstable.hg/tools/python/xen/xend/server/BlktapController.py
===================================================================
--- xen-unstable.hg.orig/tools/python/xen/xend/server/BlktapController.py
+++ xen-unstable.hg/tools/python/xen/xend/server/BlktapController.py
@@ -15,7 +15,8 @@ blktap_disk_types = [
'qcow',
'qcow2',
- 'ioemu'
+ 'ioemu',
+ 'tapdisk',
]
class BlktapController(BlkifController):
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