docs/devel/kconfig.rst

13 SCSI adapters.  Arm, s390 and x86 boards can all present a virtio-blk
21 QEMU uses a simple domain-specific language to describe the dependencies
30 * users can easily build reduced versions of QEMU that support only a subset
32   all emulated PCI devices that QEMU supports, but the build process is
36 This domain-specific language is based on the Kconfig language that
41 is instead specified in per-target files under the ``configs/``
48 --------------------
78 include it for clarity and future-proofing.  After ``bool`` the following
136 ------------------------------------
179   a video card might specify ``select EDID`` if it needs to build EDID
198   some boards (notably s390) easily support a subset of PCI devices,
199   for example only VFIO (passthrough) and virtio-pci devices.
202   board (and not ones which are very board-specific or that need
235   For some targets, not all boards may be supported by hardware
258 --------------------------------------------
261 a file called ``configs/TARGETNAME-softmmu.mak``.  These files
262 initialize some Kconfig variables to non-default values and provide the
267     # Default configuration for alpha-softmmu
278 The first part, consisting of commented-out ``=n`` assignments, tells
286 ``--without-default-devices`` option.  When this is done, everything defaults
290 want to change some lines in the first group, for example like this::
298 machine, and even then only if ``--nodefaults`` is specified on the
299 command line.  Starting a VM *without* ``--nodefaults`` is allowed to
301 ``--without-default-devices`` are considered bugs in the test code:
302 the tests should either use ``--nodefaults``, and should be skipped
303 if a necessary device is not present in the build.  Such failures
309 they will include all these symbols and some help text on what they do.
312 ----------------
314 In some special cases, a configurable element depends on host features
315 that are detected by QEMU's configure or ``meson.build`` scripts; for
316 example some devices depend on the availability of KVM or on the presence
324 and also listed as follows in the top-level meson.build's host_kconfig