Package: autopkgtest
Version: 5.28
Severity: normal
X-Debbugs-Cc: isaac@is.having.coffee

I want to pass additional kernel command line arguments to QEMU using the "-append" argument (the image is being booted with "-kernel" and "-initrd", so I cannot pass additional arguments using the bootloader), using the "--qemu-option" argument. E.g:

autopkgtest bash -- qemu --qemu-options "-append 'root=/dev/vda init=/sbin/init plus additional parameters' -kernel /boot/vmlinuz -initrd /boot/initrd.img" --boot none image.img

This should result in the command line option "-append 'root=/dev/vda init=/sbin/init plus additional parameters'" being added to QEMU.

However, the value passed to "--qemu-option" is cut up into individual arguments using the Python function split() ("qemu_options=args.qemu_options.split()" in autopkgtest-virt-qemu). This causes the quoted section to be ignored and split up into
additional arguments (irrelevant output removed):

autopkgtest-virt-qemu: DBG: full qemu command-line: ['qemu-system-aarch64', ... '-append', "'root=/dev/vda", 'init=/sbin/init', 'plus', 'additional', "parameters'", '-kernel', '/boot/vmlinuz', '-initrd', '/boot/initrd.img']

Each individual element of the "-append" argument is interpreted as an individual argument which is then additionally passed to qemu-system, as opposed to just being a single argument.

The output should look more like this:

autopkgtest-virt-qemu: DBG: full qemu command-line: ['qemu-system-aarch64', ... '-append', 'root=/dev/vda init=/sbin/init plus additional parameters', '-kernel', '/boot/vmlinuz', '-initrd', '/boot/initrd.img']


-- System Information:
Debian Release: 12.10
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.12.12+bpo-amd64 (SMP w/28 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_WARN, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_NZ.UTF-8, LC_CTYPE=en_NZ.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages autopkgtest depends on:
ii apt-utils 2.6.1
ii libdpkg-perl 1.21.22
ii procps 2:4.0.2-3
ii python3 3.11.2-1+b1
ii python3-debian 0.1.49

Versions of packages autopkgtest recommends:
ii autodep8 0.28
ii fakeroot 1.31-1.2

Versions of packages autopkgtest suggests:
ii docker.io 20.10.24+dfsg1-1+deb12u1
pn fakemachine <none>
pn lxc <none>
pn lxd <none>
ii ovmf 2022.11-6+deb12u2
pn ovmf-ia32 <none>
pn podman <none>
ii python3-distro-info 1.5+deb12u1
ii qemu-efi-aarch64 2022.11-6+deb12u2
ii qemu-efi-arm 2022.11-6+deb12u2
ii qemu-system 1:7.2+dfsg-7+deb12u12
ii qemu-utils 1:7.2+dfsg-7+deb12u12
ii schroot 1.6.13-3+b2
ii util-linux 2.38.1-5+deb12u3
ii vmdb2 0.27+really.0.26-1+deb12u1
ii zerofree 1.1.1-1

-- no debconf information

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Control: retitle -1 autopkgtest-virt-qemu: no way to pass qemu options that contain whitespace
Control: severity -1 wishlist

On Wed, 30 Apr 2025 at 16:40:59 +0200, Isaac True wrote:

the value passed to "--qemu-option" is cut up into individual arguments using the Python function split() ("qemu_options=args.qemu_options.split()" in autopkgtest-virt-qemu). This causes the quoted section to be ignored

This appears to be working as designed, although the design does not accommodate your use-case. None of the documentation mentions anything
about ability to use quoting or escaping in --qemu-option, and the
--help specifies that it's whitespace-separated:

--qemu-options QEMU_OPTIONS
Pass through (whitespace-separated) arguments to
QEMU command.

(The man page does not currently include that clarification.)

If we changed this to some more elaborate parser that interprets quotes or backslash escapes (such as shlex.split()), that would change the meaning
of existing a-v-qemu command-lines, breaking backward compatibility,
which seems like a bad idea. A new option (--qemu-options-shlex?) could
have that behaviour, though.

Or, a-v-qemu could gain explicit --kernel, --initrd, --append options
which would turn your use-case into something like:

autopkgtest ... -- qemu --append="init=... and so on" --kernel="..." --initrd="..." maindisk.qcow2

(Or both.)

A workaround could be to have a script with something like

#!/bin/sh
exec qemu-system-aarch64 -append "init=... and so on" -kernel "..." -initrd "..." "$@"

and pass the name of that script as the --qemu-command, which is likely
to be more ergonomic anyway if this is something that you are running repeatedly.

smcv

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A workaround could be to have a script

Thanks Simon, this is a great idea and I'll try it out.

Or, a-v-qemu could gain explicit --kernel, --initrd, --append options

This seems like the best and most straight-forward option for the long term in my relatively uninformed opinion. I would be happy to create a patch that adds at least `--append`.
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