tree 2724f4fa074b050a9314244cae25ae14cb8bca08
parent a5253f7cc8104c3cb162bc218d4c18a010425882
author Alexandru Elisei <alexandru.elisei@arm.com> 1632408302 +0100
committer Will Deacon <will@kernel.org> 1634028046 +0100

Add --nodefaults command line argument

kvmtool attempts to make it as easier as possible on the user to run a VM
by doing a few different things: it tries to create a rootfs filesystem in
a directory if not disk or initrd is set by the user, and it adds various
parameters to the kernel command line based on the VM configuration
options.

While this is generally very useful, today there isn't any way for the user
to prohibit this behaviour, even though there are situations where this
might not be desirable, like, for example: loading something which is not a
kernel (kvm-unit-tests comes to mind, which expects test parameters on the
kernel command line); the kernel has a built-in initramfs and there is no
need to generate the root filesystem, or it not possible; and what is
probably the most important use case, when the user is actively trying to
break things for testing purposes.

Add a --nodefaults command line argument which disables everything that
cannot be disabled via another command line switch. The purpose of this
knob is not to disable the default options for arguments that can be set
via the kvmtool command line, but rather to inhibit behaviour that cannot
be disabled otherwise.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-8-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>