On 27/06/2023 10:37, Philippe Mathieu-Daudé wrote:
On 27/6/23 08:46, Mark Cave-Ayland wrote:
On 22/06/2023 13:26, Mark Cave-Ayland wrote:
On 21/06/2023 19:05, Richard Henderson wrote:
Changes from v1:
* Split into teeny weeny pieces.
* It turns out the sparc_tr_tb_stop hunk of v1 was buggy,
in that things that are not simple branches use DYNAMIC_PC,
e.g. the RETT (return from trap) instruction.
Introduce DYNAMIC_PC_LOOKUP to distinguish the couple of
places where we have a dynamic pc, but no other change
of state (conditional branches, JMPL, RETURN).
* Drop the change for WRFPRS, because it's too infrequent.
The WRASI change affects memcpy/memset, so that's more important.
Boots Mark's sol8 install cdrom. :-)
Top of the profile changes from
41.55% qemu-system-sparc [.] cpu_exec_loop
14.02% qemu-system-sparc [.] cpu_tb_exec
8.74% qemu-system-sparc [.] tb_lookup
2.11% qemu-system-sparc [.] tcg_splitwx_to_rw
1.63% memfd:tcg-jit (deleted) [.] 0x0000000000000004
to
31.59% qemu-system-sparc [.] helper_lookup_tb_ptr
17.79% qemu-system-sparc [.] tb_lookup
5.38% qemu-system-sparc [.] compute_all_sub
2.38% qemu-system-sparc [.] helper_compute_psr
2.36% qemu-system-sparc [.] helper_check_align
1.79% memfd:tcg-jit (deleted) [.] 0x000000000063fc8e
This probably indicates that cpu_get_tb_cpu_state could be
improved to not consume so much overhead.
Nice! I've just run this through all of my sun4m/sun4u/sun4v test images and I
don't see any regressions with v2. The guests feel noticeably more responsive too :)
Tested-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
I've skimmed the patches and without looking in too much detail they seem to be
okay so I'm happy to give:
Acked-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
Side note: the niagara tests require the patch at
https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg03537.html which still
hasn't been merged yet.
Richard Henderson (8):
target/sparc: Use tcg_gen_lookup_and_goto_ptr in gen_goto_tb
target/sparc: Fix npc comparison in sparc_tr_insn_start
target/sparc: Drop inline markers from translate.c
target/sparc: Introduce DYNAMIC_PC_LOOKUP
target/sparc: Use DYNAMIC_PC_LOOKUP for conditional branches
target/sparc: Use DYNAMIC_PC_LOOKUP for JMPL
target/sparc: Use DYNAMIC_PC_LOOKUP for v9 RETURN
target/sparc: Use tcg_gen_lookup_and_goto_ptr for v9 WRASI
target/sparc/translate.c | 410 ++++++++++++++++++++++-----------------
1 file changed, 233 insertions(+), 177 deletions(-)
I've just noticed during testing there is an issue with this series when used with
a real SS-5 PROM image (I was using OpenBIOS for my previous tests) which causes it
to assert() almost immediately on startup:
$ ./qemu-system-sparc -bios ss5.bin
ERROR:../target/sparc/translate.c:5695:sparc_tr_tb_stop: code should not be
reached
Bail out! ERROR:../target/sparc/translate.c:5695:sparc_tr_tb_stop: code should not
be reached
Aborted
Could you try this fix:
-- >8 --
--- a/target/sparc/translate.c
+++ b/target/sparc/translate.c
@@ -5682,5 +5682,5 @@ static void sparc_tr_tb_stop(DisasContextBase *dcbase, CPUState
*cs)
save_npc(dc);
- switch (dc->npc) {
+ switch (dc->npc & 3) {
case DYNAMIC_PC_LOOKUP:
if (may_lookup) {
---
?
Unfortunately that doesn't fix the issue. A quick lunchtime debugging session with
printf() shows this just before the assert() fires:
### dc->pc: 0x3
### dc->npc: 0xffd26c70
**
ERROR:../target/sparc/translate.c:5699:sparc_tr_tb_stop: code should not be
reached
Bail out! ERROR:../target/sparc/translate.c:5699:sparc_tr_tb_stop: code should not be
reached
Aborted
ATB,
Mark.
