Le 13/06/2016 à 11:26, Peter Maydell a écrit : > Currently our configure script allows linux-user targets to be built > for "unknown" host CPU architectures (which must be using the TCI > interpreter). However, code like user-exec.c has host-architecture > #ifdef ladders which in practice mean you can't build linux-user for > an arbitrary host architecture. The only two host architectures which > have code in user-exec.c but aren't recognised by configure are > HPPA and m68k. > > I'd like to move to an "every supported host architecture has a > linux-user/host/$(ARCH)/hostdep.h header" model (this fixes a problem > in the code currently in master where make doesn't notice it needs to > rebuild if a host arch moves from "using generic/" to "using $(ARCH)"). > Host architectures which we sort-of-but-don't support are an annoying > corner case I'd like to be able to drop entirely, by either: > (1) just dropping the support outright > (2) promoting them to at least being recognised by configure as > a known architecture, even if one without a tcg backend > > Does this seem like a good idea? > > I think HPPA should definitely be in category (1) -- we dropped > the TCG backend years back, and I don't think any of us has a > machine to test changes on,.
I have an HPPA server sleeping in my garage, if someone needs it... > Which category should m68k host support go into? Does anybody > actually use m68k host + TCI interpreter linux-user ? My guess > is this isn't actually used, because the m68k-specific code in > user-exec.c doesn't set the "is_write" flag correctly, which means > that guests which do self-modifying code won't work (including > anything using a signal handler with an on-stack trampoline). > So my preference would be to drop the m68k-host code too. I've never tried to use an m68k computer as a QEMU host, and I think it should be horribly slow (for 68040 at 40 Mhz, and I don't have coldfire). IMHO, I see no problem to remove m68k-host (1) while it does not break qemu-m68k and qemu-system-m68k. Thanks, Laurent
