(CCing the maintainers of the machines that crash when using -nodefaults) On Tue, Nov 22, 2016 at 08:34:50PM -0200, Eduardo Habkost wrote: [...]
"default defaults" vs "-nodefault defaults" -------------------------------------------
Two bad news:
1) We need to differentiate buses created by the machine with "-nodefaults" and buses that are created only without "-nodefaults".
libvirt use -nodefaults when starting QEMU, so knowing which buses are available when using -nodefaults is more interesting for them.
Other software, on the other hand, might be interested in the results without -nodefaults.
We need to be able model both cases in the new interface. Suggestions are welcome.
The good news is that the list is short. The only[1] machines where the list of buses seem to change when using -nodefaults are: * mpc8544ds * ppce500 * mpc8544ds * ppce500 * s390-ccw-virtio-* On all cases above, the only difference is that a virtio bus is available if not using -nodefaults. Considering that the list is short, I plan to rename 'supported-device-types' to 'always-available-buses', and document that it will include only the buses that are not disabled by -nodefaults. [1] I mean, the only ones from the set that don't crash with -nodefaults. The ones below could not be tested:
2) A lot of machine-types won't start if using "-nodefaults -machine <machine>" without any extra devices or drives.
Lots of machines require some drives or devices to be created (especially ARM machines that require a SD drive to be available).
Some machines will make QEMU exit, some of them simply segfault. I am looking for ways to work around it so we can still validate -nodefaults-based info on the test code.
The following machines won't work with -nodefaults: These make QEMU segfault: * cubieboard * petalogix-ml605 * or32-sim * virtex-ml507 * Niagara These exit with a "missing SecureDigital device" error: * akita * borzoi * cheetah * connex * mainstone * n800 * n810 * spitz * sx1 * sx1-v1 * terrier * tosa * verdex * z2 -- Eduardo