On 08.12.2017 00:54, Richard Henderson wrote:
> On 12/07/2017 08:53 AM, David Hildenbrand wrote:
>> It only provides the EXTRACT CPU TIME instruction. We can reuse the stpt
>> helper, which calculates the CPU timer value.
>>
>> As the instruction is not privileged, but we don't have a CPU timer
>> value in case of linux user, we simply fake the CPU timer to be 0.
>>
>> Signed-off-by: David Hildenbrand <da...@redhat.com>
>> ---
>> target/s390x/cpu_models.c | 1 +
>> target/s390x/insn-data.def | 2 ++
>> target/s390x/translate.c | 36 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 39 insertions(+)
>>
>> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
>> index 94d24e423d..0be037eac1 100644
>> --- a/target/s390x/cpu_models.c
>> +++ b/target/s390x/cpu_models.c
>> @@ -834,6 +834,7 @@ static void add_qemu_cpu_model_features(S390FeatBitmap
>> fbm)
>> S390_FEAT_STORE_CLOCK_FAST,
>> S390_FEAT_MOVE_WITH_OPTIONAL_SPEC,
>> S390_FEAT_ETF3_ENH,
>> + S390_FEAT_EXTRACT_CPU_TIME,
>> S390_FEAT_COMPARE_AND_SWAP_AND_STORE,
>> S390_FEAT_COMPARE_AND_SWAP_AND_STORE_2,
>> S390_FEAT_GENERAL_INSTRUCTIONS_EXT,
>> diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
>> index f7b66b0091..5e33bd27ff 100644
>> --- a/target/s390x/insn-data.def
>> +++ b/target/s390x/insn-data.def
>> @@ -369,6 +369,8 @@
>> C(0xb24f, EAR, RRE, Z, 0, 0, new, r1_32, ear, 0)
>> /* EXTRACT CPU ATTRIBUTE */
>> C(0xeb4c, ECAG, RSY_a, GIE, 0, a2, r1, 0, ecag, 0)
>> +/* EXTRACT CPU TIME */
>> + C(0xc801, ECTG, SSF, ECT, 0, 0, 0, 0, ectg, 0)
>> /* EXTRACT FPC */
>> C(0xb38c, EFPC, RRE, Z, 0, 0, new, r1_32, efpc, 0)
>> /* EXTRACT PSW */
>> diff --git a/target/s390x/translate.c b/target/s390x/translate.c
>> index 1e4079464a..e0f55fc8e9 100644
>> --- a/target/s390x/translate.c
>> +++ b/target/s390x/translate.c
>> @@ -3887,6 +3887,41 @@ static ExitStatus op_spm(DisasContext *s, DisasOps *o)
>> return NO_EXIT;
>> }
>>
>> +static ExitStatus op_ectg(DisasContext *s, DisasOps *o)
>> +{
>> + int b1 = get_field(s->fields, b1);
>> + int d1 = get_field(s->fields, d1);
>> + int b2 = get_field(s->fields, b2);
>> + int d2 = get_field(s->fields, d2);
>> + int r3 = get_field(s->fields, r3);
>> + TCGv_i64 tmp = tcg_temp_new_i64();
>> +
>> + /* fetch all operands first */
>> + o->in1 = tcg_temp_new_i64();
>> + tcg_gen_addi_i64(o->in1, regs[b1], d1);
>> + o->in2 = tcg_temp_new_i64();
>> + tcg_gen_addi_i64(o->in2, regs[b2], d2);
>> + o->addr1 = get_address(s, 0, r3, 0);
>> +
>> + /* load the third operand into r3 before modifying anything */
>> + tcg_gen_qemu_ld64(regs[r3], o->addr1, get_mem_index(s));
>> +
>> +#ifndef CONFIG_USER_ONLY
>> + /* subtract CPU timer from first operand and store in GR0 */
>> + gen_helper_stpt(tmp, cpu_env);
>> + tcg_gen_sub_i64(regs[0], o->in1, tmp);
>> +#else
>> + /* we don't have a CPU timer, fake value 0 */
>> + tcg_gen_mov_i64(regs[0], o->in1);
>> +#endif
>
> It's easy enough to pass along cpu_get_host_ticks() for user-only. Possibly
> not quite right, but better than nothing.
>
>
> r~
>
What about this:
+/* Store CPU Timer (also used for EXTRACT CPU TIME) */
+uint64_t HELPER(stpt)(CPUS390XState *env)
+{
+#if defined(CONFIG_USER_ONLY)
+ /*
+ * Fake a descending CPU timer. We could get negative values here,
+ * but we don't care as it is up to the OS when to process that
+ * interrupt and reset to > 0.
+ */
+ return UINT64_MAX - (uint64_t)cpu_get_host_ticks();
+#else
+ return time2tod(env->cputm - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+#endif
+}
+
--
Thanks,
David / dhildenb
