On 23/01/2017 20:16, Markus Armbruster wrote: >> Could we change >> those messages to errors > > Fine with me, but when it comes to arguing for backward compatibility of > our byzantine command line, I'm kind of like a lethargic public defender > with an overly deep relationship to Bourbon. "Your honor, sure capital > punishment is called for? Yes? Okay then." > > I vaguely recall discussing the topic with Peter (cc'ed). If memory > serves, one concern was breaking usage of -device with -drive lacking > if=... Works fine (no warning) with machines that don't pick up drives > with their default block interface type, i.e. most of them. But PATCH 3 > changes their default to if=none, so that usage wouldn't actually break.
I think that tips the scale in favor of having errors. > What would break is -device with -drive if=T, where T is not none and > not picked up by the board. Such usage is certainly questionable[*], > but it's questionable enough for us to break it? > >> and then drop PC if=scsi support altogether? > > Different backward compatibility question: here we break usage of > if=scsi with PC machine types. Legacy way to do things, but it's > documented in qemu.1. Are we happy to break it? That usage is wrong after this patch, since it mentions qemu-system-i386. So it's documented, but almost useless and the example is not exactly correct. Let's deprecate it in 2.9 and remove in 2.10. Paolo
