This series is a side effect of other work I started, to attempt to make the QGA safe to use in confidential VMs by automatically restricting the permitted commands. Since this cleanup stands on its own, I'm sending it now.
The QGA codebase has a very complicated maze of #ifdefs to create stubs for the various commands that cannot be implemented on certain platforms. It then has further logic to dynamically disable the stub commands at runtime, except this is not consistently applied, so some commands remain enabled despite being merely stubs. The resulting code is hard to follow, when trying to understand exactly what commands are available under what circumstances, and when changing impls it is easy to get the #ifdefs wrong, resulting in stubs getting missed on platforms without a real impl. In some cases, we have multiple stubs for the same command, due to the maze of #ifdefs. The QAPI schema language has support for many years for expressing conditions against commands when declaring them. This results in the QAPI code generator omitting their implementation entirely at build time. This has mutliple benefits * The unsupported commands are guaranteed to not exist at runtime * No stubs need ever be defined in the code * The generated QAPI reference manual documents the build conditions This series is broadly split into three parts * Moving tonnes of Linux only commands out of commands-posix.c into commands-linux.c to remove many #ifdefs. * Adding 'if' conditions in the QAPI schema to reflect the build conditions, removing many more #ifdefs * Sanitizing the logic for disabling/enabling commands at runtime to guarantee consistency Daniel P. Berrangé (20): qga: drop blocking of guest-get-memory-block-size command qga: move linux vcpu command impls to commands-linux.c qga: move linux suspend command impls to commands-linux.c qga: move linux fs/disk command impls to commands-linux.c qga: move linux disk/cpu stats command impls to commands-linux.c qga: move linux memory block command impls to commands-linux.c qga: move CONFIG_FSFREEZE/TRIM to be meson defined options qga: conditionalize schema for commands unsupported on Windows qga: conditionalize schema for commands unsupported on non-Linux POSIX qga: conditionalize schema for commands requiring getifaddrs qga: conditionalize schema for commands requiring linux/win32 qga: conditionalize schema for commands only supported on Windows qga: conditionalize schema for commands requiring fsfreeze qga: conditionalize schema for commands requiring fstrim qga: conditionalize schema for commands requiring libudev qga: conditionalize schema for commands requiring utmpx qga: conditionalize schema for commands not supported on other UNIX qga: add note about where to disable commands for a platform qga: move declare of QGAConfig struct to top of file qga: centralize logic for disabling/enabling commands meson.build | 19 + qga/commands-bsd.c | 24 - qga/commands-common.h | 9 - qga/commands-linux.c | 1805 +++++++++++++++++++++++++++++++ qga/commands-posix.c | 2375 ++++------------------------------------- qga/commands-win32.c | 64 +- qga/main.c | 154 +-- qga/qapi-schema.json | 153 ++- 8 files changed, 2196 insertions(+), 2407 deletions(-) -- 2.45.1
