From: Stefan Hajnoczi <[email protected]>
Make it possible to boot directly from a virtiofs file system with tag
'myfs' using the following kernel parameters:
rootfstype=virtiofs root=myfs rw
Booting directly from virtiofs makes it possible to use a directory on
the host as the root file system. This is convenient for testing and
situations where manipulating disk image files is cumbersome.
Reviewed-by: Helen Koike <[email protected]>
Signed-off-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: David Heidelberg <[email protected]>
---
v2: added Reviewed-by and CCed everyone interested.
We have used this option in Mesa3D CI for testing crosvm for
more than one years and it's proven to work reliably.
We are working on effort to removing custom patches to be able to do
automated apply and test of patches from any tree.
https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/.gitlab-ci/crosvm-runner.sh#L85
init/do_mounts.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 811e94daf0a8..11c11abe23d7 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -578,6 +578,16 @@ void __init mount_root(void)
printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
return;
}
+#endif
+#ifdef CONFIG_VIRTIO_FS
+ if (root_fs_names && !strcmp(root_fs_names, "virtiofs")) {
+ if (!do_mount_root(root_device_name, "virtiofs",
+ root_mountflags, root_mount_data))
+ return;
+
+ panic("VFS: Unable to mount root fs \"%s\" from virtiofs",
+ root_device_name);
+ }
#endif
if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
if (mount_nodev_root() == 0)
--
2.39.1
On Fri, Feb 24, 2023 at 03:37:51PM +0100, David Heidelberg wrote:
> From: Stefan Hajnoczi <[email protected]>
>
> Make it possible to boot directly from a virtiofs file system with tag
> 'myfs' using the following kernel parameters:
>
> rootfstype=virtiofs root=myfs rw
>
> Booting directly from virtiofs makes it possible to use a directory on
> the host as the root file system. This is convenient for testing and
> situations where manipulating disk image files is cumbersome.
>
> Reviewed-by: Helen Koike <[email protected]>
> Signed-off-by: Stefan Hajnoczi <[email protected]>
> Signed-off-by: David Heidelberg <[email protected]>
> ---
> v2: added Reviewed-by and CCed everyone interested.
>
> We have used this option in Mesa3D CI for testing crosvm for
> more than one years and it's proven to work reliably.
>
> We are working on effort to removing custom patches to be able to do
> automated apply and test of patches from any tree.
>
> https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/.gitlab-ci/crosvm-runner.sh#L85
> init/do_mounts.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
Vivek, do you remember where we ended up with boot from virtiofs? I
thought a different solution was merged some time ago.
There is documentation from the virtiofs community here:
https://virtio-fs.gitlab.io/howto-boot.html
Stefan
>
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 811e94daf0a8..11c11abe23d7 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -578,6 +578,16 @@ void __init mount_root(void)
> printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
> return;
> }
> +#endif
> +#ifdef CONFIG_VIRTIO_FS
> + if (root_fs_names && !strcmp(root_fs_names, "virtiofs")) {
> + if (!do_mount_root(root_device_name, "virtiofs",
> + root_mountflags, root_mount_data))
> + return;
> +
> + panic("VFS: Unable to mount root fs \"%s\" from virtiofs",
> + root_device_name);
> + }
> #endif
> if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
> if (mount_nodev_root() == 0)
> --
> 2.39.1
>
On Mon, Feb 27, 2023 at 10:53:45AM -0500, Stefan Hajnoczi wrote:
> On Fri, Feb 24, 2023 at 03:37:51PM +0100, David Heidelberg wrote:
> > From: Stefan Hajnoczi <[email protected]>
> >
> > Make it possible to boot directly from a virtiofs file system with tag
> > 'myfs' using the following kernel parameters:
> >
> > rootfstype=virtiofs root=myfs rw
> >
> > Booting directly from virtiofs makes it possible to use a directory on
> > the host as the root file system. This is convenient for testing and
> > situations where manipulating disk image files is cumbersome.
> >
> > Reviewed-by: Helen Koike <[email protected]>
> > Signed-off-by: Stefan Hajnoczi <[email protected]>
> > Signed-off-by: David Heidelberg <[email protected]>
> > ---
> > v2: added Reviewed-by and CCed everyone interested.
> >
> > We have used this option in Mesa3D CI for testing crosvm for
> > more than one years and it's proven to work reliably.
> >
> > We are working on effort to removing custom patches to be able to do
> > automated apply and test of patches from any tree.
> >
> > https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/.gitlab-ci/crosvm-runner.sh#L85
> > init/do_mounts.c | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
>
> Vivek, do you remember where we ended up with boot from virtiofs? I
> thought a different solution was merged some time ago.
We merged a patch from Christoph Hellwig to support this.
commit f9259be6a9e7c22d92e5a5000913147ae17e8321
Author: Christoph Hellwig <[email protected]>
Date: Wed Jul 14 16:23:20 2021 -0400
init: allow mounting arbitrary non-blockdevice filesystems as root
Now one should be able to mount virtiofs using following syntax.
"root=myfs rootfstype=virtiofs rw"
IIUC, this patch should not be required anymore.
Thanks
Vivek
>
> There is documentation from the virtiofs community here:
> https://virtio-fs.gitlab.io/howto-boot.html
>
> Stefan
>
> >
> > diff --git a/init/do_mounts.c b/init/do_mounts.c
> > index 811e94daf0a8..11c11abe23d7 100644
> > --- a/init/do_mounts.c
> > +++ b/init/do_mounts.c
> > @@ -578,6 +578,16 @@ void __init mount_root(void)
> > printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
> > return;
> > }
> > +#endif
> > +#ifdef CONFIG_VIRTIO_FS
> > + if (root_fs_names && !strcmp(root_fs_names, "virtiofs")) {
> > + if (!do_mount_root(root_device_name, "virtiofs",
> > + root_mountflags, root_mount_data))
> > + return;
> > +
> > + panic("VFS: Unable to mount root fs \"%s\" from virtiofs",
> > + root_device_name);
> > + }
> > #endif
> > if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
> > if (mount_nodev_root() == 0)
> > --
> > 2.39.1
> >
Thank you all!
We'll drop this patch in next MesaCI kernel uprev without this patch!
David
On 27/02/2023 19:06, Vivek Goyal wrote:
> On Mon, Feb 27, 2023 at 10:53:45AM -0500, Stefan Hajnoczi wrote:
>> On Fri, Feb 24, 2023 at 03:37:51PM +0100, David Heidelberg wrote:
>>> From: Stefan Hajnoczi <[email protected]>
>>>
>>> Make it possible to boot directly from a virtiofs file system with tag
>>> 'myfs' using the following kernel parameters:
>>>
>>> rootfstype=virtiofs root=myfs rw
>>>
>>> Booting directly from virtiofs makes it possible to use a directory on
>>> the host as the root file system. This is convenient for testing and
>>> situations where manipulating disk image files is cumbersome.
>>>
>>> Reviewed-by: Helen Koike <[email protected]>
>>> Signed-off-by: Stefan Hajnoczi <[email protected]>
>>> Signed-off-by: David Heidelberg <[email protected]>
>>> ---
>>> v2: added Reviewed-by and CCed everyone interested.
>>>
>>> We have used this option in Mesa3D CI for testing crosvm for
>>> more than one years and it's proven to work reliably.
>>>
>>> We are working on effort to removing custom patches to be able to do
>>> automated apply and test of patches from any tree.
>>>
>>> https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/.gitlab-ci/crosvm-runner.sh#L85
>>> init/do_mounts.c | 10 ++++++++++
>>> 1 file changed, 10 insertions(+)
>> Vivek, do you remember where we ended up with boot from virtiofs? I
>> thought a different solution was merged some time ago.
> We merged a patch from Christoph Hellwig to support this.
>
> commit f9259be6a9e7c22d92e5a5000913147ae17e8321
> Author: Christoph Hellwig <[email protected]>
> Date: Wed Jul 14 16:23:20 2021 -0400
>
> init: allow mounting arbitrary non-blockdevice filesystems as root
>
> Now one should be able to mount virtiofs using following syntax.
>
> "root=myfs rootfstype=virtiofs rw"
>
> IIUC, this patch should not be required anymore.
>
> Thanks
> Vivek
>
>> There is documentation from the virtiofs community here:
>> https://virtio-fs.gitlab.io/howto-boot.html
>>
>> Stefan
>>
>>> diff --git a/init/do_mounts.c b/init/do_mounts.c
>>> index 811e94daf0a8..11c11abe23d7 100644
>>> --- a/init/do_mounts.c
>>> +++ b/init/do_mounts.c
>>> @@ -578,6 +578,16 @@ void __init mount_root(void)
>>> printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
>>> return;
>>> }
>>> +#endif
>>> +#ifdef CONFIG_VIRTIO_FS
>>> + if (root_fs_names && !strcmp(root_fs_names, "virtiofs")) {
>>> + if (!do_mount_root(root_device_name, "virtiofs",
>>> + root_mountflags, root_mount_data))
>>> + return;
>>> +
>>> + panic("VFS: Unable to mount root fs \"%s\" from virtiofs",
>>> + root_device_name);
>>> + }
>>> #endif
>>> if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
>>> if (mount_nodev_root() == 0)
>>> --
>>> 2.39.1
>>>
>
--
David Heidelberg
Consultant Software Engineer