Peter Maydell <peter.mayd...@linaro.org> writes: > On Thu, 1 Feb 2024 at 14:01, Jonathan Cameron > <jonathan.came...@huawei.com> wrote: >> > Can you run QEMU under gdb and give the backtrace when it stops >> > on the abort() ? That will probably have a helpful clue. I >> > suspect something is failing to pass a valid retaddr in >> > when it calls a load/store function. > >> [Switching to Thread 0x7ffff56ff6c0 (LWP 21916)] >> __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized out>) >> at ./nptl/pthread_kill.c:44 >> 44 ./nptl/pthread_kill.c: No such file or directory. >> (gdb) bt >> #0 __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized >> out>) at ./nptl/pthread_kill.c:44 >> #1 __pthread_kill_internal (signo=6, threadid=<optimized out>) at >> ./nptl/pthread_kill.c:78 >> #2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at >> ./nptl/pthread_kill.c:89 >> #3 0x00007ffff77c43b6 in __GI_raise (sig=sig@entry=6) at >> ../sysdeps/posix/raise.c:26 >> #4 0x00007ffff77aa87c in __GI_abort () at ./stdlib/abort.c:79 >> #5 0x0000555555c0d4ce in cpu_abort >> (cpu=cpu@entry=0x555556fd9000, fmt=fmt@entry=0x555555fe3378 >> "cpu_io_recompile: could not find TB for pc=%p") >> at ../../cpu-target.c:359 >> #6 0x0000555555c59435 in cpu_io_recompile (cpu=cpu@entry=0x555556fd9000, >> retaddr=retaddr@entry=0) at ../../accel/tcg/translate-all.c:611 >> #7 0x0000555555c5c956 in io_prepare >> (retaddr=0, addr=19595792376, attrs=..., xlat=<optimized out>, >> cpu=0x555556fd9000, out_offset=<synthetic pointer>) >> at ../../accel/tcg/cputlb.c:1339 <snip> >> #21 tb_htable_lookup (cpu=<optimized out>, pc=pc@entry=18446744072116178925, >> cs_base=0, flags=415285936, cflags=4278353920) >> at ../../accel/tcg/cpu-exec.c:231 >> #22 0x0000555555c50c08 in tb_lookup >> (cpu=cpu@entry=0x555556fd9000, pc=pc@entry=18446744072116178925, >> cs_base=cs_base@entry=0, flags=<optimized out>, cflags=<optimized out>) at >> ../../accel/tcg/cpu-exec.c:267 >> #23 0x0000555555c51e23 in helper_lookup_tb_ptr (env=0x555556fdb7c0) at >> ../../accel/tcg/cpu-exec.c:423 >> #24 0x00007fffa9076ead in code_gen_buffer () >> #25 0x0000555555c50fab in cpu_tb_exec (cpu=cpu@entry=0x555556fd9000, >> itb=<optimized out>, tb_exit=tb_exit@entry=0x7ffff56fe708) >> at ../../accel/tcg/cpu-exec.c:458 >> #26 0x0000555555c51492 in cpu_loop_exec_tb >> (tb_exit=0x7ffff56fe708, last_tb=<synthetic pointer>, >> pc=18446744072116179169, tb=<optimized out>, cpu=0x555556fd9000) >> at ../../accel/tcg/cpu-exec.c:920 >> #27 cpu_exec_loop (cpu=cpu@entry=0x555556fd9000, sc=sc@entry=0x7ffff56fe7a0) >> at ../../accel/tcg/cpu-exec.c:1041 >> #28 0x0000555555c51d11 in cpu_exec_setjmp (cpu=cpu@entry=0x555556fd9000, >> sc=sc@entry=0x7ffff56fe7a0) at ../../accel/tcg/cpu-exec.c:1058 >> #29 0x0000555555c523b4 in cpu_exec (cpu=cpu@entry=0x555556fd9000) at >> ../../accel/tcg/cpu-exec.c:1084 >> #30 0x0000555555c74053 in tcg_cpus_exec (cpu=cpu@entry=0x555556fd9000) at >> ../../accel/tcg/tcg-accel-ops.c:76 >> #31 0x0000555555c741a0 in mttcg_cpu_thread_fn (arg=arg@entry=0x555556fd9000) >> at ../../accel/tcg/tcg-accel-ops-mttcg.c:95 >> #32 0x0000555555dfb580 in qemu_thread_start (args=0x55555703c3e0) at >> ../../util/qemu-thread-posix.c:541 >> #33 0x00007ffff78176ba in start_thread (arg=<optimized out>) at >> ./nptl/pthread_create.c:444 >> #34 0x00007ffff78a60d0 in clone3 () at >> ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 > > So, that looks like: > * we call cpu_tb_exec(), which executes some generated code > * that generated code calls the lookup_tb_ptr helper to see > if we have a generated TB already for the address we're going > to execute next > * lookup_tb_ptr probes the TLB to see if we know the host RAM > address for the guest address > * this results in a TLB walk for an instruction fetch > * the page table descriptor load is to IO memory > * io_prepare assumes it needs to do a TLB recompile, because > can_do_io is clear > > I am not surprised that the corner case of "the guest put its > page tables in an MMIO device" has not yet come up :-) > > I'm really not sure how the icount handling should interact > with that...
Its not just icount - we need to handle it for all modes now. That said seeing as we are at the end of a block shouldn't can_do_io be set? Does: modified accel/tcg/translator.c @@ -201,6 +201,8 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns, } } + set_can_do_io(db, true); + /* Emit code to exit the TB, as indicated by db->is_jmp. */ ops->tb_stop(db, cpu); gen_tb_end(tb, cflags, icount_start_insn, db->num_insns); do the trick? > > -- PMM -- Alex Bennée Virtualisation Tech Lead @ Linaro