@@ -76,11 +76,13 @@ static const char *guest_mac;
static const char *host_mac;
static const char *script;
static const char *guest_name;
+static const char *rootfs;
static bool single_step;
static bool readonly_image[MAX_DISK_IMAGES];
static bool vnc;
static bool sdl;
static bool balloon;
+static bool bin_sh;
extern bool ioport_debug;
extern int active_console;
extern int debug_iodelay;
@@ -156,6 +158,8 @@ static const struct option options[] = {
OPT_BOOLEAN('\0', "balloon", &balloon, "Enable virtio balloon"),
OPT_BOOLEAN('\0', "vnc", &vnc, "Enable VNC framebuffer"),
OPT_BOOLEAN('\0', "sdl", &sdl, "Enable SDL framebuffer"),
+ OPT_STRING('\0', "rootfs", &rootfs, "path", "Use path as rootfs"),
+ OPT_BOOLEAN('\0', "binsh", &bin_sh, "Boot rootfs to /bin/sh instead of /sbin/init"),
OPT_GROUP("Kernel options:"),
OPT_STRING('k', "kernel", &kernel_filename, "kernel",
@@ -615,7 +619,7 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
strlcat(real_cmdline, kernel_cmdline, sizeof(real_cmdline));
hi = NULL;
- if (!image_filename[0]) {
+ if (!rootfs && !image_filename[0]) {
hi = host_image(real_cmdline, sizeof(real_cmdline));
if (hi) {
image_filename[0] = hi;
@@ -627,6 +631,18 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
if (!strstr(real_cmdline, "root="))
strlcat(real_cmdline, " root=/dev/vda rw ", sizeof(real_cmdline));
+ if (rootfs) {
+ char tmp[PATH_MAX];
+
+ if (realpath(rootfs, tmp) == 0 ||
+ virtio_9p__init(kvm, tmp, "/dev/root") < 0)
+ die("Unable to initialize virtio 9p");
+ strcat(real_cmdline, " root=/dev/root rootflags=rw,trans=virtio,version=9p2000.u rootfstype=9p");
+
+ if (bin_sh)
+ strcat(real_cmdline, " init=/bin/sh");
+ }
+
if (image_count) {
kvm->nr_disks = image_count;
kvm->disks = disk_image__open_all(image_filename, readonly_image, image_count);
This patch adds 2 new flags: --rootfs [path] - Specifies a path to use as rootfs. The path will be mounted using virtio-9p and booted from. Easiest way to test it is to mount the sample image we recommend with kvm tool (http://wiki.qemu.org/download/linux-0.2.img.bz2) and mounting it somewhere. *PLEASE DO NOT TRY BOOTING FROM YOUR REAL ROOT AKA '/', EVEN WITH READ ONLY SET* - Lets make sure the code is bulletproof before we delete your rootfs :) --binsh - This flag will boot into simple /bin/sh shell instead of going through /sbin/init. This is usefull for more complex distribution rootfs where we have to deal with /etc/fstab and such. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> --- tools/kvm/builtin-run.c | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-)