On 12.06.2017 18:44, Thomas Huth wrote:
> On 01.03.2017 13:19, Miroslav Benes wrote:
>> On Wed, 1 Mar 2017, Thomas Huth wrote:
>>
>>> On 28.02.2017 14:17, Miroslav Benes wrote:
>>>> Implement MVCOS instruction, which the Linux kernel uses in user access
>>>> functions.
>>>>
>>>> Signed-off-by: Miroslav Benes <mbe...@suse.cz>
>>>> ---
>>>> I tried to do my best to follow the specification but it is quite
>>>> possible that I got something wrong because of my lack of
>>>> understanding. Especially I am not sure about all those bit ops :/.
>>>>
>>>> Anyway, there is one piece missing. The actual use of keys and
>>>> address-space-control during the move. I used fast_memmove, but
>>>> it is not correct. Is there a helper which I could use? I looked at
>>>> other instructions which should implement access control, but there were
>>>> silently ignore it :).
>>>
>>> I'm not aware of a function that could deal with two address spaces
>>> already (but that does not mean that there is no such function already)
>>> ... still, I guess, you likely need to write your own memmove helper
>>> function that can deal with two different address spaces.
>>
>> Ok, I thought that was the case. I'll try to come up with something.
>>
>>>> target/s390x/helper.h | 1 +
>>>> target/s390x/insn-data.def | 2 ++
>>>> target/s390x/mem_helper.c | 80
>>>> ++++++++++++++++++++++++++++++++++++++++++++++
>>>> target/s390x/translate.c | 12 +++++++
>>>> 4 files changed, 95 insertions(+)
>>>>
>>>> diff --git a/target/s390x/helper.h b/target/s390x/helper.h
>>>> index 9102071d0aa4..bc5dfccc3d7e 100644
>>>> --- a/target/s390x/helper.h
>>>> +++ b/target/s390x/helper.h
>>>> @@ -104,6 +104,7 @@ DEF_HELPER_FLAGS_2(iske, TCG_CALL_NO_RWG_SE, i64, env,
>>>> i64)
>>>> DEF_HELPER_FLAGS_3(sske, TCG_CALL_NO_RWG, void, env, i64, i64)
>>>> DEF_HELPER_FLAGS_2(rrbe, TCG_CALL_NO_RWG, i32, env, i64)
>>>> DEF_HELPER_3(csp, i32, env, i32, i64)
>>>> +DEF_HELPER_5(mvcos, i32, env, i64, i64, i64, i64)
>>>> DEF_HELPER_4(mvcs, i32, env, i64, i64, i64)
>>>> DEF_HELPER_4(mvcp, i32, env, i64, i64, i64)
>>>> DEF_HELPER_4(sigp, i32, env, i64, i32, i64)
>>>> diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
>>>> index 075ff597c3de..a1e6d735d090 100644
>>>> --- a/target/s390x/insn-data.def
>>>> +++ b/target/s390x/insn-data.def
>>>> @@ -854,6 +854,8 @@
>>>> /* LOAD USING REAL ADDRESS */
>>>> C(0xb24b, LURA, RRE, Z, 0, r2, new, r1_32, lura, 0)
>>>> C(0xb905, LURAG, RRE, Z, 0, r2, r1, 0, lurag, 0)
>>>> +/* MOVE WITH OPTIONAL SPECIFICATION */
>>>> + C(0xc800, MVCOS, SSF, MVCOS, la1, a2, 0, 0, mvcos, 0)
>>>> /* MOVE TO PRIMARY */
>>>> C(0xda00, MVCP, SS_d, Z, la1, a2, 0, 0, mvcp, 0)
>>>> /* MOVE TO SECONDARY */
>>>> diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
>>>> index 675aba2e44d4..ca8f7c49250c 100644
>>>> --- a/target/s390x/mem_helper.c
>>>> +++ b/target/s390x/mem_helper.c
>>>> @@ -1089,6 +1089,86 @@ uint32_t HELPER(mvcp)(CPUS390XState *env, uint64_t
>>>> l, uint64_t a1, uint64_t a2)
>>>> return cc;
>>>> }
>>>>
>>>> +uint32_t HELPER(mvcos)(CPUS390XState *env, uint64_t r0, uint64_t dest,
>>>> + uint64_t src, uint64_t len)
>>>> +{
>>>> + int cc;
>>>> + int key1, as1, abit1, kbit1;
>>>> + int key2, as2, abit2, kbit2;
>>>> +
>>>> + HELPER_LOG("%s dest %" PRIx64 ", src %" PRIx64 ", len %" PRIx64 "\n",
>>>> + __func__, dest, src, len);
>>>> +
>>>> + /* check DAT */
>>>> + if (!(env->psw.mask & PSW_MASK_DAT)) {
>>>> + program_interrupt(env, PGM_SPECIAL_OP, 2);
>>>
>>> Length of the opcode is 6 bytes, not 2.
>>
>> True. Sorry, I don't know where 2 came from. It does not make sense.
>
> As I recently had to learn it the hard way (while implementing the TEST
> BLOCK instruction), you should use ILEN_LATER_INC here instead of 2 (or
> 6), since the Special operation exception is suppressing, too, i.e. the
> program counter should be increased afterwards to the next instruction.
>
This is no longer needed with
https://lists.nongnu.org/archive/html/qemu-devel/2017-06/msg02631.html
You can either use 6 or ILEN_AUTO here, suppression will be handled
internally.
> BTW, are you still working on a new version of this patch?
>
> Thomas
>
--
Thanks,
David
