Commit Graph
267 Commits
Author SHA1 Message Date
Zbigniew Jędrzejewski-Szmek 74573799ca Add DEFINE_ARRAY_DONE_FUNC
This is a helper macro that defines a function to drop elements of an
array but not the array itself. I used the "_many" suffix because it
most closely matches what happens here: we are calling the cleanup
function a bunch of times.
2026-04-10 15:08:02 +02:00
Zbigniew Jędrzejewski-Szmek e2227c8a20 nspawn,vmspawn: fixups for recent changes
Nits found in post-merge review for
bf5bc9a7b2 and
4c778c51c0.
2026-04-08 23:19:03 +02:00
Zbigniew Jędrzejewski-Szmek 4c778c51c0 vmspawn: convert to the new option parser
Uses stop_at_first_nonoption for POSIX-style option parsing.

--help output is the same, apart from whitespace differences
and common strings.

The error message for --ssh-key-type= is fixed.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-07 23:55:51 +02:00
Daan De Meyer e4f535fdca vmspawn: Always enable CXL on supported architectures
Drop the --cxl= option and unconditionally enable cxl=on the QEMU
machine type whenever the host architecture supports it (x86_64 and
aarch64). The flag was only added for testing parity with mkosi's CXL=
setting and there is no reason to leave it as an opt-in toggle: with no
pxb-cxl device or cxl-fmw window attached, enabling it on the machine
only reserves a small MMIO region and emits an empty CEDT, so the cost
is negligible while removing one knob users would otherwise have to
flip explicitly to exercise the CXL code paths in QEMU.
2026-04-07 12:47:31 +02:00
Christian Brauner ccecae0efd vmspawn: use machine name in runtime directory path
Replace the random hex suffix in the runtime directory with the machine
name, changing the layout from /run/systemd/vmspawn.<random> to
/run/systemd/vmspawn/<machine-name>/.

This makes runtime directories machine-discoverable from the filesystem
and groups all vmspawn instances under a shared parent directory, similar
to how nspawn uses /run/systemd/nspawn/.

Use runtime_directory_generic() instead of runtime_directory() since
vmspawn is not a service with RuntimeDirectory= set and the
$RUNTIME_DIRECTORY check in the latter never succeeds. The directory is
always created by vmspawn itself and cleaned up via
rm_rf_physical_and_freep on exit. The parent vmspawn/ directory is
intentionally left behind as a shared namespace.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-04-06 22:09:55 +02:00
Christian Brauner 454d9c1be1 shared: introduce MachineRegistrationContext to track bus and registration state
Bundle scope, buses, and registration success booleans into a
MachineRegistrationContext struct. This eliminates the reterr_registered_system and
reterr_registered_user output parameters from
register_machine_with_fallback_and_log() and the corresponding input
parameters from unregister_machine_with_fallback_and_log().

The struct carries state from registration to unregistration so the
caller no longer needs to manually thread individual booleans between
the two calls.

register_machine_with_fallback_and_log() goes from 7 to 3 parameters,
unregister_machine_with_fallback_and_log() goes from 5 to 2.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-04-06 21:42:15 +02:00
Christian Brauner 2af171653f shared: introduce MachineRegistration struct for machine registration
Replace the long positional parameter lists in register_machine() and
register_machine_with_fallback_and_log() with a MachineRegistration
struct that bundles all machine-describing fields.

This reduces register_machine() from 13 parameters to 3 and
register_machine_with_fallback_and_log() from 17 parameters to 7.
Callers now use designated initializers, which makes omitted fields
(zero/NULL/false) implicit and the code much more readable.

Field names are aligned with the existing Machine struct in machine.h
(id, root_directory, vsock_cid, ssh_address, ssh_private_key_path).

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-04-06 21:42:15 +02:00
Christian Brauner 2b77bbeb20 vmspawn: only open runtime bus when needed for registration or scope allocation
The runtime bus (user bus in user scope, system bus in system scope) is
only needed for scope allocation (!arg_keep_unit) or machine registration
(arg_register != 0). When both are disabled the bus was still opened
unconditionally which causes unnecessary failures if the user bus is
unavailable.

Gate the runtime bus opening on the same condition nspawn already uses.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-04-06 21:42:15 +02:00
Christian Brauner d872be82a0 vmspawn: fix error message when opening user bus
The error message incorrectly says "system bus" when the code is
actually opening the user bus via sd_bus_default_user().

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-04-06 21:42:15 +02:00
Daan De Meyer e7fb7296f5 nspawn: rename --user= to --uid= and repurpose --user/--system for runtime scope
Rename nspawn's --user=NAME option to --uid=NAME for selecting the
container user. The -u short option is preserved. --user=NAME and
--user NAME are still accepted but emit a deprecation warning. A
pre-parsing step stitches the space-separated --user NAME form into
--user=NAME before getopt sees it, preserving backwards compatibility
despite --user now being an optional_argument.

Repurpose --user (without argument) and --system as standalone
switches for selecting the runtime scope (user vs system service
manager).

Replace all uses of the arg_privileged boolean with
arg_runtime_scope comparisons throughout nspawn. The default scope
is auto-detected from the effective UID.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-06 18:49:40 +02:00
Daan De Meyer 1e084aad7d shared: move machine registration to shared machine-register.{c,h}
Move register_machine() and unregister_machine() from
vmspawn-register.{c,h} into shared machine-register.{c,h} so both
nspawn and vmspawn can use the same implementation.

The unified register_machine() uses varlink first (for richer
features like SSH support and unit allocation) with a D-Bus
RegisterMachineWithNetwork fallback for older machined. The
interface adds a class parameter ("vm" or "container") and
local_ifindex for nspawn's network interface support.

The unified unregister_machine() similarly tries varlink first
(io.systemd.Machine.Unregister) before falling back to D-Bus.

Both register_machine() and unregister_machine() only log at debug
level internally, leaving error/notice logging to callers.

Add register_machine_with_fallback() which tries system and/or user
scope registration based on a RuntimeScope parameter
(_RUNTIME_SCOPE_INVALID for both), and
unregister_machine_with_fallback() as its counterpart. Both use
RET_GATHER() to collect errors from each scope.

Make --register= a tristate (yes/no/auto) defaulting to auto. When
set to auto, registration failures are logged at notice level and
ignored. When set to yes, failures are fatal.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-06 17:13:40 +02:00
Daan De Meyer bde83a9e1e vmspawn: Redirect QEMU's stdin/stdout/stderr to the PTY
When a PTY is allocated for the console, QEMU's own stdio file
descriptors were still inherited directly from vmspawn, meaning any
output QEMU writes to stdout/stderr (e.g. warnings) would bypass the
PTY forwarder and go straight to the terminal. Similarly, QEMU could
read directly from the terminal's stdin.

Fix this by opening the PTY slave side and passing it as stdio_fds to
the fork call with FORK_REARRANGE_STDIO, so that all of QEMU's I/O
goes through the PTY and is properly forwarded.
2026-04-06 13:58:31 +02:00
Daan De Meyer fb4bfe651b vmspawn: Use ~ instead of ! as negation prefix for --firmware-features=
Switch the negation character for firmware feature exclusion from
"!" to "~" to be consistent with other systemd options that support
negation such as SystemCallFilter=.
2026-04-05 21:09:23 +02:00
Daan De Meyer a85845f043 vmspawn: Add comment explaining substring match in firmware_data_matches_machine()
The machine types in QEMU firmware descriptions are glob patterns
like "pc-q35-*", so we use strstr() substring matching to check if
our machine type is covered by a given firmware entry.
2026-04-05 21:09:23 +02:00
Daan De Meyer ba937b45be vmspawn: Fix qemu-kvm path on centos stream
Follow up for 41da1ae6a0
2026-04-05 18:51:17 +02:00
Daan De Meyer 41da1ae6a0 vmspawn: also search for qemu binary at /usr/lib/qemu-kvm
This is the qemu binary path on CentOS Stream.
2026-04-05 09:55:09 +02:00
Daan De Meyer 6a9888c4c6 vmspawn: add --cxl= option and memory hotplug support
Add --cxl=BOOL option to enable CXL (Compute Express Link) support in
the virtual machine. CXL is a high-speed interconnect standard that
allows CPUs to access memory attached to devices such as accelerators
and memory expanders, enabling flexible memory pooling and expansion
beyond what is physically installed on the motherboard. When enabled,
adds cxl=on to the QEMU machine configuration. Only supported on x86_64
and aarch64 architectures.

This is added for testing purposes and for feature parity with mkosi's
CXL= setting.

Extend --ram= to accept an optional maximum size for memory hotplug,
using the syntax --ram=SIZE[:MAXSIZE] (e.g. --ram=2G:8G). When a
maximum is specified, the maxmem key is added to the QEMU memory
configuration section to enable memory hotplug up to the given limit.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-03 16:31:42 +02:00
Daan De Meyer 0ef9bf9723 vmspawn: drop ICH9-LPC S3 disable and guard cfi.pflash01 for x86
The ICH9-LPC disable_s3 global QEMU config was a workaround for an
OVMF limitation where S3 resume didn't work with X64 PEI + SMM. SMM is
required for secure boot as it prevents the guest from writing directly
to the pflash, bypassing UEFI variable protections. With X64 PEI + SMM
enabled and S3 advertised, OVMF would hang on S3 resume. The
workaround was to tell QEMU not to advertise S3 support.

This limitation has been resolved in edk2 — the S3Verification() check
was removed in edk2 commit 098c5570 ("OvmfPkg/PlatformPei: drop
S3Verification()") after edk2 gained native X64 PEI + SMM + S3 resume
support. See https://github.com/tianocore/edk2/commit/098c5570.

Drop the now-unnecessary ICH9-LPC disable_s3 config entirely, and
guard the cfi.pflash01 secure=on setting with an x86 architecture
check since SMM is x86-specific and this option is invalid on ARM.
2026-04-03 10:20:58 +02:00
Lennart Poettering d90d0a1f63 kernel-image: minor refactoring to inspect_kernel()
Let's add make three arguments optional, by splitting inspect_kernel()
from inspect_kernel_full().

Let's also downgrade logging to debug, so that this becomes more
library-like. Let's log on the call-site instead.
2026-04-03 08:15:27 +02:00
Lennart Poettering 7f5bea5b78 vmspawn: simplify kernel_cmdline_maybe_append_root() 2026-04-02 23:28:33 +02:00
Lennart Poettering 275e31f44c vmspawn: shorten find_virtiofsd() a bit 2026-04-02 23:28:33 +02:00
Lennart Poettering f83e47bd57 vmspawn: add a bunch of func param assert()s 2026-04-02 23:28:33 +02:00
Daan De Meyer a586648800 vmspawn: Add --console-transport= option to select serial vs virtio-serial
Add a --console-transport= option that selects between virtio-serial
(the default, appearing as /dev/hvc0) and a regular serial port
(appearing as /dev/ttyS0 or /dev/ttyAMA0 depending on architecture).

This is primarily useful for testing purposes, for example to test
sd-stub's automatic console= kernel command line parameter handling. It
allows verifying that the guest OS correctly handles serial console
configurations without virtio.

When serial transport is selected, -serial chardev:console is used on
the QEMU command line to connect the chardev to the platform's default
serial device. This cannot be done via the QEMU config file as on some
platforms (e.g. ARM) the serial device is a sysbus device that can only
be connected via serial_hd() which is populated by -serial.
2026-04-02 20:43:42 +02:00
Daan De Meyer dcce04e649 vmspawn: propagate $TERM from host into VM via kernel command line
When running in a console mode (interactive, native, or read-only),
propagate the host's $TERM into the VM by adding TERM= and
systemd.tty.term.hvc0= to the kernel command line.

TERM= is picked up by PID 1 and inherited by services on /dev/console
(such as emergency.service). systemd.tty.term.hvc0= is used by services
directly attached to /dev/hvc0 (such as serial-getty@hvc0.service) which
look up $TERM via the systemd.tty.term.<tty> kernel command line
parameter.

While systemd can auto-detect the terminal type via DCS XTGETTCAP, not
all terminal emulators implement this, so explicitly propagating $TERM
provides a more reliable experience. We skip propagation when $TERM is
unset or set to "unknown" (as is the case in GitHub Actions and some
other CI environments).

Previously this was handled by mkosi synthesizing the corresponding
kernel command line parameters externally.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-02 18:06:10 +02:00
Daan De Meyer 214f7f0b8a vmspawn: Warn about --grow-image= in combo with --image-disk-type=scsi-cd 2026-04-02 18:04:29 +02:00
Daan De Meyer e98a26ddc0 vmspawn: use fstab.extra credential for runtime mounts instead of kernel cmdline
Switch runtime virtiofs mount configuration from systemd.mount-extra=
kernel command line parameters to the fstab.extra credential. This
avoids consuming kernel command line space (which is limited) and
matches the approach used by mkosi.

Each mount is added as an fstab entry in the format:
  {tag} {destination} virtiofs {ro|rw},x-initrd.mount

If the user already specified a fstab.extra credential via
--set-credential= or --load-credential=, the virtiofs mount entries
are appended to it rather than conflicting.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-02 16:03:29 +02:00
Daan De Meyer 2371c9e798 vmspawn: add scsi-cd disk type for ISO/CD-ROM image support
Add DISK_TYPE_SCSI_CD to support attaching disk images as CD-ROM
drives, needed for testing El Torito ISO images built by
systemd-repart.

When --image-disk-type=scsi-cd is specified, the image is attached
with media=cdrom and readonly=on on the drive, using scsi-cd as the
device driver on the SCSI bus. This also works for --extra-drive=
with the scsi-cd: prefix.

The QEMU configuration matches the standard OVMF CD-ROM boot setup:
  -drive if=none,media=cdrom,format=raw,readonly=on
  -device virtio-scsi-pci
  -device scsi-cd

When direct kernel booting with scsi-cd, if the kernel command line
contains "rw", append "ro" to override it since CD-ROMs are
read-only.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-02 16:02:43 +02:00
Daan De Meyer 1b7a42178a vmspawn: use PTY for native console to avoid QEMU O_NONBLOCK issue
QEMU's stdio chardev sets O_NONBLOCK on both stdin and stdout (see
chardev/char-stdio.c [1] and chardev/char-fd.c [2]). Since forked
processes share file descriptions, and on a terminal all three stdio
fds typically reference the same file description, this affects our
own stdio too.

Avoid this by using a PTY with chardev serial instead of chardev
stdio for native console mode, matching the approach already used
for interactive and read-only modes. The PTY forwarder shovels bytes
transparently between our stdio and QEMU's PTY using the new
PTY_FORWARD_DUMB_TERMINAL and PTY_FORWARD_TRANSPARENT flags, which
disable terminal decoration (background tinting, window title, OSC
context) and escape sequence handling (Ctrl-] exit, hotkeys)
respectively.

The chardev is configured with mux=on so the QEMU monitor remains
accessible via Ctrl-a c.

Also dedup CONSOLE_NATIVE, CONSOLE_READ_ONLY, and CONSOLE_INTERACTIVE
handling by using fallthrough, with the only differences being the
ptyfwd flags, mux setting, and monitor section.

[1] https://gitlab.com/qemu-project/qemu/-/blob/master/chardev/char-stdio.c
[2] https://gitlab.com/qemu-project/qemu/-/blob/master/chardev/char-fd.c

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-02 15:12:52 +02:00
Daan De Meyer 73c0a79789 vmspawn: Use qemu config file for smp and memory
Pass -no-user-config while we're at it to avoid loading qemu config
from /etc which is more likely to cause hard to debug issues rather
than do something useful.
2026-04-02 13:19:40 +02:00
Daan De Meyer fd1b84af98 vmspawn: pass --log-level=error and --modcaps=-mknod to virtiofsd
Reduce virtiofsd log noise by setting --log-level=error, and drop
the unnecessary mknod capability with --modcaps=-mknod, matching
mkosi's virtiofsd invocation.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-02 13:03:36 +02:00
Daan De Meyer ca347a9494 vmspawn: Pass extra cmdline via smbios when direct booting a UKI
-cmdline doesn't work when direct booting a UKI so use SMBIOS instead.
2026-04-02 10:18:48 +02:00
Daan De Meyer bb5c7328cf vmspawn: improve firmware selection to match mkosi's implementation
Align find_ovmf_config() with mkosi's find_ovmf_firmware() by adding
checks that were previously missing:

- Filter on interface-types, only selecting UEFI firmware definitions.
  Previously non-UEFI (e.g. BIOS-only) firmware could be selected.

- Check machine type compatibility using substring matching against the
  target machine patterns in firmware descriptions (e.g. "q35" matches
  "pc-q35-*"), following the same approach as mkosi.

- Make nvram-template optional in the firmware JSON mapping. Firmware
  definitions without an nvram-template are now parsed successfully
  (with vars remaining NULL) rather than failing entirely.

Also rework the firmware target parsing to store both architecture and
machine arrays per target (instead of just a flat architecture list),
and extract the machine matching into firmware_data_matches_machine().

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-27 14:22:29 +01:00
Daan De Meyer d6e5fbca73 vmspawn: Add --firmware=describe
It's useful to be able to check what firmware description vmspawn
will select. In particular, this will allow me to figure out the
nvram template file that will be picked up so I can pick it up in
mkosi and operate on it to pass a modified version of it to vmspawn
with --efi-nvram-template=.
2026-03-27 14:22:29 +01:00
Daan De Meyer 5a7d70e807 vmspawn: add --efi-nvram-template= and --firmware-features= options
Add --efi-nvram-template=PATH to specify a custom firmware variables
file to copy and use as the initial EFI NVRAM state instead of the
default template from the firmware definition.

Add --firmware-features=FEATURE[,FEATURE...] to require or exclude
specific firmware features during automatic firmware discovery.
Features prefixed with "!" are excluded. If a feature appears in both
the included and excluded lists, inclusion takes priority. Firmware
with the "enrolled-keys" feature is excluded by default.

Refactor --secure-boot= to operate on the firmware features sets
instead of maintaining a separate tristate. --secure-boot=yes adds
"secure-boot" to the include set, --secure-boot=no adds it to the
exclude set, and --secure-boot=auto removes it from both.

Generalize find_ovmf_config() to accept include/exclude feature sets
instead of a secure boot tristate, removing the special-cased
enrolled-keys and secure-boot filtering logic.

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-27 14:22:29 +01:00
Daan De Meyer 8ff77aac13 vmspawn: Use qemu config files
Let's avoid generating giant qemu command lines by using qemu config
files instead.
2026-03-25 22:12:54 +01:00
Daan De Meyer f83371324d vmspawn: Create journal parent directories if needed 2026-03-25 21:55:19 +01:00
Daan De Meyer 5442fbfb07 vmspawn: Fix --tpm-state= parsing
path_startswith() considers "no" and "./no" equal. Use startswith()
to avoid that.
2026-03-25 21:54:51 +01:00
Daan De Meyer 4c02d63b36 vmspawn: Fix --help width 2026-03-24 22:43:44 +01:00
Lennart Poettering fb17ad1581 vmspawn: add disk type selection for root and extra drives (#41301)
vmspawn previously hardcoded virtio-blk for all drives. This adds
  --image-disk-type= to select the root disk type (virtio-blk,
  virtio-scsi, or nvme) and allows per-drive overrides via a
  colon-separated prefix on --extra-drive=. The format and disk type
  prefixes can appear in any order since their value sets don't overlap.

  For virtio-scsi, a single shared controller is created with drives
  attached as scsi-hd devices. For nvme, each drive gets its own
controller. Both have serial number length limits (30 and 20 characters
  respectively), so long filenames are replaced with a truncated SHA-256
  hex digest.
2026-03-24 21:48:00 +01:00
Daan De Meyer a8c2aa9e2f vmspawn: Add headless console support 2026-03-24 21:36:19 +01:00
Christian Brauner b76e1732f7 vmspawn: add nvme disk type support
Extend --image-disk-type= and the --extra-drive= disk type prefix to
support nvme in addition to virtio-blk and virtio-scsi:

  systemd-vmspawn --image-disk-type=nvme --image=image.raw
  systemd-vmspawn --image=image.raw --extra-drive=nvme:data.raw

The NVMe serial number is limited to 20 characters by the NVMe spec.
If the image filename exceeds this, it is hashed with SHA-256 and
truncated to 20 hex characters via the disk_serial() helper introduced
in the previous commit.

Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-24 16:53:41 +01:00
Christian Brauner e4a58c38e9 vmspawn: add virtio-scsi disk type support
Add --image-disk-type= to select the disk type for the root disk, and
allow specifying the disk type as a colon-separated prefix on
--extra-drive=:

  systemd-vmspawn --image-disk-type=virtio-scsi --image=image.raw
  systemd-vmspawn --image=image.raw --extra-drive=virtio-scsi:data.raw

For --extra-drive=, the format and disk type prefixes can appear in any
order since the value sets don't overlap:

  --extra-drive=raw:virtio-scsi:/path
  --extra-drive=virtio-scsi:raw:/path

Extra drives inherit --image-disk-type= by default unless overridden
with an explicit prefix.

vmspawn originally used virtio-scsi for all drives but switched to
virtio-blk in 1f24a954e4 for simplicity and direct kernel boot
compatibility. This makes virtio-scsi available again as an explicit
option for cases where a SCSI storage topology is desired.

For virtio-scsi, a shared virtio-scsi-pci controller is created and
drives are attached as scsi-hd devices. The SCSI serial number is
limited to 30 characters, so filenames exceeding this are hashed with
SHA-256.

Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-24 16:53:40 +01:00
Lennart Poettering dc91cb82da vmspawn: split out swtpm-setup logic, and beef it up a bit 2026-03-24 14:42:39 +01:00
Lennart Poettering 9996cfd2c9 vmspawn: manage EFI nvram (variables) state similar to TPM state 2026-03-24 14:40:08 +01:00
Lennart Poettering 5cd3462014 vmspawn: make efi variable nvram dependent on whether the EFI profile knows the concept, not on secureboot 2026-03-24 14:40:08 +01:00
Daan De Meyer da580dc161 vmspawn: Drop --sandbox=chroot from virtiofsd command line
It's unclear why I added this in fd05c6c759,
but it breaks bind mounting regular directories via --bind,
so drop it again since it's not actually required to make virtiofsd
work with the foreign UID range.
2026-03-24 11:21:02 +00:00
Lennart Poettering 2c74a91cb8 sd-json: when parsing optionally insist top-level variant is object or array
Typically, the top-level JSON object has to be an object, in any json
document we parse, hence let's add a simple way to enforce that.

Make use of this in various places.

(Note, various other JSON parsers insist on this logic right from the
beginning, but I actually thinking making this insisting optional like
this patch does it is the cleaner approach)
2026-03-20 15:34:56 +01:00
Mike Yuan 769b0bf746 various: mark arg_* as static 2026-03-04 14:32:15 +01:00
Zbigniew Jędrzejewski-Szmek a8637c059b vmspawn: change order of fields in --extra-drive=
Closes #40877. As requested, --extra-drive=path[:format] is changed
to --extra-drive=[format:]path, so that the parsing is less ambiguous.
(In the original request, it was requested that the empty format can be
used also, but that was dropped in the second version of the patch.)
2026-03-04 07:05:32 +09:00
Daan De Meyer fd05c6c759 vmspawn: Add support for foreign UID range owned directories 2026-02-25 11:31:04 +01:00