On 05/12/2015 12:23 AM, Peter Crosthwaite wrote: > In my multi-compile approach helper_*[ld|st]* needs to be renamed > per-arch for the multiple compiled cputlb.o. Hence I have no symbol > with the unqualified name. But even if I do solve my namespacing > problem, I still have an ambiguity of which cputlb.o provided > helper_*[ld|st]* to use from the TCG backend. This would mean all > those APIs would have to virtualised. The big question for Paolo, is > what complete set of APIs defines the common-code/non-common-code > boundary? tlb_fill does seem to do the job nicely and looking at the > architecture implementations it's not a super fast path (falling back > to a page table faulter). > > Somewhere along the call path from the qemu_st_helpers uses > (tcg/i386/tcg-target.c) through to tlb_fill there has to be a > virtualised function unless I am missing something?
I think both cpu_unaligned_access and tlb_fill need to be hooked. >> I think that this is a decent step forward, modulo the conditionals along the >> use paths. I think we ought to clean up all of the translators to the new >> QOM >> hooks. >> > > So the conditional can be ditched by having the CPU base class > defaulting the hook to the globally defined function. Then arches can > be brought online one-by-one. Yes, exactly. > Ok so the solution to this is to opt-out of the hook via a re-#define > when we have a target-specific cpu.h handy. This will actually mean no > change to single-arch builds but multi-arch will use the hook from > core code only. Err... not via #defines, please. Just use the <arch>_foo name all spelled out from target-specific code. > I don't know what this means exactly. tlb_fill is called by functions > that are linked to common code (TCG backends) so I don't see a non > virtualized solution. Is this refactoring to move tlb_fill? It means if we do find a way to parameterize the tcg backend, e.g. by putting the whole table of functions into the class, then we can revisit generating cpu-specific versions of the memory helpers. r~
