| Message ID | 1312310789-22817-2-git-send-email-levinsasha928@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2 Aug 2011 21:46:29 +0300, Sasha Levin <levinsasha928@gmail.com> wrote: > 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> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > --- > tools/kvm/builtin-run.c | 18 +++++++++++++++++- > 1 files changed, 17 insertions(+), 1 deletions(-) > > diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c > index 2e04265..78680ec 100644 > --- a/tools/kvm/builtin-run.c > +++ b/tools/kvm/builtin-run.c > @@ -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); > -- > 1.7.6 > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 8/3/11 5:52 AM, Aneesh Kumar K.V wrote: > On Tue, 2 Aug 2011 21:46:29 +0300, Sasha Levin<levinsasha928@gmail.com> wrote: >> 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> > Reviewed-by: Aneesh Kumar K.V<aneesh.kumar@linux.vnet.ibm.com> > >> --- >> tools/kvm/builtin-run.c | 18 +++++++++++++++++- >> 1 files changed, 17 insertions(+), 1 deletions(-) >> >> diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c >> index 2e04265..78680ec 100644 >> --- a/tools/kvm/builtin-run.c >> +++ b/tools/kvm/builtin-run.c >> @@ -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"); >> + } >> Why don't we use the "-d" command line option for this? We can use fstat() and S_ISDIR to detect that the user specified a directory as a disk image? I'm also not completely convinced we should introduce the 'binsh' command line option. Instead, I'd simply default to 'init=/bin/sh' unless the user uses -p to specify init. Pekka -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/03/2011 02:46 AM, Sasha Levin wrote: > 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> This is damn impressive! All I needed is: ./kvm run -k /home/asias/qemu-stuff/bzImage --rootfs /mnt/ I found that if I boot with ./kvm run -k /home/asias/qemu-stuff/bzImage --rootfs /mnt/ I will get: sh-2.05b# echo a > /root/a sh: /root/a: No such file or directory If I boot with sudo ./kvm run -k /home/asias/qemu-stuff/bzImage --rootfs /mnt/ sh-2.05b# echo a > /root/a works. It seems that it is a permission related problem, however, the warning message is "/root/a: No such file or directory", any ideas?
diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c index 2e04265..78680ec 100644 --- a/tools/kvm/builtin-run.c +++ b/tools/kvm/builtin-run.c @@ -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(-)