| Message ID | 20231208003754.3688038-4-iii@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | accel/tcg: Move perf and debuginfo support to tcg | expand |
Ilya Leoshkevich <iii@linux.ibm.com> writes: > Preparation for moving perf.c to tcg/. > > This affects only profiling guest code, which has code in a non-0 based > segment, e.g., 16-bit code, which is not particularly important. I have no objection to removing the wart. Is it worth adding a note:: to tcg.rst to say that profiles of 16-bit x64 code will be junk? Anyway: Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > > Suggested-by: Richard Henderson <richard.henderson@linaro.org> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> > --- > accel/tcg/perf.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/accel/tcg/perf.c b/accel/tcg/perf.c > index ba75c1bbe45..68a46b1b524 100644 > --- a/accel/tcg/perf.c > +++ b/accel/tcg/perf.c > @@ -337,10 +337,6 @@ void perf_report_code(uint64_t guest_pc, TranslationBlock *tb, > q[insn].address = gen_insn_data[insn * start_words + 0]; > if (tb_cflags(tb) & CF_PCREL) { > q[insn].address |= (guest_pc & qemu_target_page_mask()); > - } else { > -#if defined(TARGET_I386) > - q[insn].address -= tb->cs_base; > -#endif > } > q[insn].flags = DEBUGINFO_SYMBOL | (jitdump ? DEBUGINFO_LINE : 0); > }
On Fri, 2023-12-08 at 09:53 +0000, Alex Bennée wrote: > Ilya Leoshkevich <iii@linux.ibm.com> writes: > > > Preparation for moving perf.c to tcg/. > > > > This affects only profiling guest code, which has code in a non-0 > > based > > segment, e.g., 16-bit code, which is not particularly important. > > I have no objection to removing the wart. Is it worth adding a note:: > to > tcg.rst to say that profiles of 16-bit x64 code will be junk? > > Anyway: > > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> I haven't tried them, but I don't think they work well anyway. With the current logic, the samples are assigned to ip (without cs!), so if there is code in different segments, there will be, to put it mildly, ambiguities. Come to think of it, the patch even improves the situation, since now the samples are assigned to cs*16+ip. In any case, I don't think there is any good tooling to work with 16-bit profiles. > > Suggested-by: Richard Henderson <richard.henderson@linaro.org> > > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> > > --- > > accel/tcg/perf.c | 4 ---- > > 1 file changed, 4 deletions(-) > > > > diff --git a/accel/tcg/perf.c b/accel/tcg/perf.c > > index ba75c1bbe45..68a46b1b524 100644 > > --- a/accel/tcg/perf.c > > +++ b/accel/tcg/perf.c > > @@ -337,10 +337,6 @@ void perf_report_code(uint64_t guest_pc, > > TranslationBlock *tb, > > q[insn].address = gen_insn_data[insn * start_words + 0]; > > if (tb_cflags(tb) & CF_PCREL) { > > q[insn].address |= (guest_pc & > > qemu_target_page_mask()); > > - } else { > > -#if defined(TARGET_I386) > > - q[insn].address -= tb->cs_base; > > -#endif > > } > > q[insn].flags = DEBUGINFO_SYMBOL | (jitdump ? > > DEBUGINFO_LINE : 0); > > } >
On 12/7/23 16:35, Ilya Leoshkevich wrote: > Preparation for moving perf.c to tcg/. > > This affects only profiling guest code, which has code in a non-0 based > segment, e.g., 16-bit code, which is not particularly important. > > Suggested-by: Richard Henderson <richard.henderson@linaro.org> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> > --- > accel/tcg/perf.c | 4 ---- > 1 file changed, 4 deletions(-) > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/accel/tcg/perf.c b/accel/tcg/perf.c index ba75c1bbe45..68a46b1b524 100644 --- a/accel/tcg/perf.c +++ b/accel/tcg/perf.c @@ -337,10 +337,6 @@ void perf_report_code(uint64_t guest_pc, TranslationBlock *tb, q[insn].address = gen_insn_data[insn * start_words + 0]; if (tb_cflags(tb) & CF_PCREL) { q[insn].address |= (guest_pc & qemu_target_page_mask()); - } else { -#if defined(TARGET_I386) - q[insn].address -= tb->cs_base; -#endif } q[insn].flags = DEBUGINFO_SYMBOL | (jitdump ? DEBUGINFO_LINE : 0); }
Preparation for moving perf.c to tcg/. This affects only profiling guest code, which has code in a non-0 based segment, e.g., 16-bit code, which is not particularly important. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> --- accel/tcg/perf.c | 4 ---- 1 file changed, 4 deletions(-)