File xl-create-pv-with-qcow2-img.patch of Package xen
Fix problem that xl cannot create PV guest with qcow/qcow2 disk image by using
pygrub. Have discussed with upstream, but the work is something related to both
qemu and xen upstream, making it accepted may take a long time. Submit first and
will be replaced with upstream patches if it is accepted.
http://xen.1045712.n5.nabble.com/xl-create-PV-guest-with-qcow-qcow2-disk-images-fail-td4909399.html
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Index: xen-4.1.2-testing/tools/libxl/libxl.c
===================================================================
--- xen-4.1.2-testing.orig/tools/libxl/libxl.c
+++ xen-4.1.2-testing/tools/libxl/libxl.c
@@ -1071,11 +1071,131 @@ int libxl_device_disk_del(libxl_ctx *ctx
return rc;
}
+static int libxl_forkexec(libxl_ctx *ctx, char *arg0, char **args)
+{
+ pid_t pid;
+ int status;
+
+ pid = libxl_fork(ctx);
+ if (pid < 0)
+ return -1;
+ else if (pid == 0){
+ libxl__exec(-1, -1, -1, arg0, args);
+ exit(127);
+ }
+ while (waitpid(pid, &status, 0) < 0) {
+ if (errno != EINTR) {
+ status = -1;
+ break;
+ }
+ }
+
+ return status;
+}
+
+#ifdef __linux__
+static int is_nbd_used(int minor)
+{
+ FILE *proc;
+ int NBDMAJOR = 43;
+ char buf[BUFSIZ];
+ int find = 0;
+
+ proc = fopen("/proc/partitions", "r");
+ if (proc != NULL) {
+ while (fgets(buf, sizeof(buf), proc)) {
+ int m, n;
+ unsigned long long sz;
+ char name[16];
+ char *pname = name;
+ char *end;
+
+ if (sscanf(buf, " %d %d %llu %128[^\n ]",
+ &m, &n, &sz, name) != 4)
+ continue;
+ if (m != NBDMAJOR)
+ continue;
+ if (strncmp(name, "nbd", 3))
+ continue;
+ pname += 3;
+ n = strtol(pname, &end, 10);
+ if (end && end != pname && *end == '\0' && n == minor) {
+ find = 1;
+ break;
+ }
+ }
+ fclose(proc);
+ }
+
+ return find;
+}
+
+static int find_free_nbd_minor(void)
+{
+ int i;
+ int nbds_max = 16;
+ int minor = -1;
+
+ for (i = 0; i < nbds_max; i++) {
+ if (!is_nbd_used(i)) {
+ minor = i;
+ break;
+ }
+ }
+
+ return minor;
+}
+
+static char * nbd_mount_disk(libxl__gc *gc, libxl_device_disk *disk)
+{
+ libxl_ctx *ctx = libxl__gc_owner(gc);
+ int n = -1;
+ char *nbd_dev = NULL;
+ char *args[] = {"qemu-nbd","-c",NULL,NULL,NULL};
+ char *ret = NULL;
+
+ n = find_free_nbd_minor();
+ if (n >= 0) {
+ int i = 0;
+ int retry = 3;
+
+ nbd_dev = libxl__sprintf(gc, "/dev/nbd%d", n);
+ args[2] = libxl__sprintf(gc, "%s", nbd_dev);
+ args[3] = libxl__sprintf(gc, "%s", disk->pdev_path);
+ libxl_forkexec(ctx, args[0], args);
+
+ /*check connection*/
+ while (i < retry) {
+ if (is_nbd_used(n)) {
+ ret = strdup(nbd_dev);
+ break;
+ }
+ i++;
+ sleep(1);
+ }
+ }
+
+ return ret;
+}
+
+static int nbd_unmount_disk(libxl__gc *gc, char *diskpath) {
+ libxl_ctx *ctx = libxl__gc_owner(gc);
+ char *args[] = {"qemu-nbd","-d",NULL,NULL};
+
+ args[2] = libxl__sprintf(gc, "%s", diskpath);
+ if (libxl_forkexec(ctx, args[0], args))
+ return 0;
+ else
+ return ERROR_FAIL;
+}
+#endif
+
char * libxl_device_disk_local_attach(libxl_ctx *ctx, libxl_device_disk *disk)
{
libxl__gc gc = LIBXL_INIT_GC(ctx);
const char *dev = NULL;
char *ret = NULL;
+ char *mdev = NULL;
switch (disk->backend) {
case DISK_BACKEND_PHY:
@@ -1117,8 +1237,17 @@ char * libxl_device_disk_local_attach(li
}
case DISK_BACKEND_QDISK:
if (disk->format != DISK_FORMAT_RAW) {
- LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "cannot locally attach a qdisk "
- "image if the format is not raw");
+#ifdef __linux__
+ LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "attaching a non-raw qdisk image to domain 0\n");
+ mdev = nbd_mount_disk(&gc, disk);
+ if (mdev)
+ dev = mdev;
+ else
+ LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "fail to mount image with qemu-nbd");
+#else
+ LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "cannot locally"
+ " attach a qdisk image if the format is not raw");
+#endif
break;
}
LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "attaching qdisk %s to domain 0\n",
@@ -1134,18 +1263,37 @@ char * libxl_device_disk_local_attach(li
if (dev != NULL)
ret = strdup(dev);
+ free(mdev);
libxl__free_all(&gc);
return ret;
}
-int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk)
+int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk, char *diskpath)
{
- /* Nothing to do for PHYSTYPE_PHY. */
+#ifdef __linux__
+ libxl__gc gc = LIBXL_INIT_GC(ctx);
+ int ret;
+
+ switch (disk->backend) {
+ case DISK_BACKEND_QDISK:
+ if (disk->format != DISK_FORMAT_RAW) {
+ LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "Locally detach a non-raw "
+ "qdisk image");
+ ret = nbd_unmount_disk(&gc, diskpath);
+ return ret;
+ }
+ default:
+ /* Nothing to do for PHYSTYPE_PHY. */
- /*
- * For other device types assume that the blktap2 process is
- * needed by the soon to be started domain and do nothing.
- */
+ /*
+ * For other device types assume that the blktap2 process is
+ * needed by the soon to be started domain and do nothing.
+ */
+ break;
+ }
+
+ libxl__free_all(&gc);
+#endif
return 0;
}
Index: xen-4.1.2-testing/tools/libxl/libxl.h
===================================================================
--- xen-4.1.2-testing.orig/tools/libxl/libxl.h
+++ xen-4.1.2-testing/tools/libxl/libxl.h
@@ -429,7 +429,7 @@ int libxl_cdrom_insert(libxl_ctx *ctx, u
* Make a disk available in this domain. Returns path to a device.
*/
char * libxl_device_disk_local_attach(libxl_ctx *ctx, libxl_device_disk *disk);
-int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk);
+int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk, char *diskpath);
int libxl_device_nic_init(libxl_device_nic *nic, int dev_num);
int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic);
Index: xen-4.1.2-testing/tools/libxl/libxl_bootloader.c
===================================================================
--- xen-4.1.2-testing.orig/tools/libxl/libxl_bootloader.c
+++ xen-4.1.2-testing/tools/libxl/libxl_bootloader.c
@@ -419,7 +419,7 @@ int libxl_run_bootloader(libxl_ctx *ctx,
rc = 0;
out_close:
if (diskpath) {
- libxl_device_disk_local_detach(ctx, disk);
+ libxl_device_disk_local_detach(ctx, disk, diskpath);
free(diskpath);
}
if (fifo_fd > -1)
