Re: [Qemu-devel] [RISU PATCH v5 07/13] risu: paramterise send/receive functions

[Alex Bennée]

Peter Maydell <address@hidden> writes:

> On 19 June 2017 at 11:46, Alex Bennée <address@hidden> wrote:
>> This is a precursor to record/playback support. Instead of passing the
>> socket fd we now pass helper functions for reading/writing and
>> responding. This will allow us to do the rest of the record/playback
>> cleanly outside of the main worker function.
>>
>> Signed-off-by: Alex Bennée <address@hidden>
>>
>> ---
>> v5
>>   - re-base without tab/format cleanps
>> v4
>>   - split header code
>>   - fix formatting foo-bar's
>> v3
>>   - new for v3
>>   - arm, aarch64, ppc64
>> ---
>>  reginfo.c | 39 +++++++++++++++++++--------------------
>>  risu.c    | 23 +++++++++++++++++++++--
>>  risu.h    | 11 +++++++++--
>>  3 files changed, 49 insertions(+), 24 deletions(-)
>>
>> diff --git a/reginfo.c b/reginfo.c
>> index 31bb99f..90cea8f 100644
>> --- a/reginfo.c
>> +++ b/reginfo.c
>> @@ -21,7 +21,7 @@ uint8_t apprentice_memblock[MEMBLOCKLEN];
>>  static int mem_used;
>>  static int packet_mismatch;
>>
>> -int send_register_info(int sock, void *uc)
>> +int send_register_info(write_fn write_fn, void *uc)
>>  {
>>      struct reginfo ri;
>>      int op;
>> @@ -29,24 +29,25 @@ int send_register_info(int sock, void *uc)
>>      op = get_risuop(&ri);
>>
>>      switch (op) {
>> -    case OP_COMPARE:
>>      case OP_TESTEND:
>> -    default:
>> -        /* Do a simple register compare on (a) explicit request
>> -         * (b) end of test (c) a non-risuop UNDEF
>> -         */
>> -        return send_data_pkt(sock, &ri, sizeof(ri));
>> +        write_fn(&ri, sizeof(ri));
>> +        return 1;
>
> Why the change from "return write function's return value"
> to "ignore return value and always return 1" for OP_TESTEND ?

Hmm possibly a re-base snaggle. I'll fix it up.

>
>>      case OP_COMPAREMEM:
>> -        return send_data_pkt(sock, memblock, MEMBLOCKLEN);
>> +        return write_fn(memblock, MEMBLOCKLEN);
>>          break;
>
> ...here we still just pass the return value through, for instance.
>
>> +    case OP_COMPARE:
>> +    default:
>> +        /* Do a simple register compare on (a) explicit request
>> +         * (b) end of test (c) a non-risuop UNDEF
>> +         */
>> +        return write_fn(&ri, sizeof(ri));
>>      }
>>      return 0;
>>  }
>> @@ -59,7 +60,7 @@ int send_register_info(int sock, void *uc)
>>   * that says whether it is register or memory data, so if the two
>>   * sides get out of sync then we will fail obscurely.
>>   */
>> -int recv_and_compare_register_info(int sock, void *uc)
>> +int recv_and_compare_register_info(read_fn read_fn, respond_fn resp_fn, 
>> void *uc)
>>  {
>>      int resp = 0, op;
>>
>> @@ -73,36 +74,34 @@ int recv_and_compare_register_info(int sock, void *uc)
>>          /* Do a simple register compare on (a) explicit request
>>           * (b) end of test (c) a non-risuop UNDEF
>>           */
>> -        if (recv_data_pkt(sock, &apprentice_ri, sizeof(apprentice_ri))) {
>> +        if (read_fn(&apprentice_ri, sizeof(apprentice_ri))) {
>>              packet_mismatch = 1;
>>              resp = 2;
>> -
>>          } else if (!reginfo_is_eq(&master_ri, &apprentice_ri)) {
>>              /* register mismatch */
>>              resp = 2;
>> -
>>          } else if (op == OP_TESTEND) {
>>              resp = 1;
>>          }
>> -        send_response_byte(sock, resp);
>> +        resp_fn(resp);
>>          break;
>>      case OP_SETMEMBLOCK:
>> -        memblock = (void *) (uintptr_t) get_reginfo_paramreg(&master_ri);
>> +        memblock = (void *)(uintptr_t)get_reginfo_paramreg(&master_ri);
>>          break;
>>      case OP_GETMEMBLOCK:
>>          set_ucontext_paramreg(uc, get_reginfo_paramreg(&master_ri) +
>> -                              (uintptr_t) memblock);
>> +                              (uintptr_t)memblock);
>>          break;
>>      case OP_COMPAREMEM:
>>          mem_used = 1;
>> -        if (recv_data_pkt(sock, apprentice_memblock, MEMBLOCKLEN)) {
>> +        if (read_fn(apprentice_memblock, MEMBLOCKLEN)) {
>>              packet_mismatch = 1;
>>              resp = 2;
>>          } else if (memcmp(memblock, apprentice_memblock, MEMBLOCKLEN) != 0) 
>> {
>>              /* memory mismatch */
>>              resp = 2;
>>          }
>> -        send_response_byte(sock, resp);
>> +        resp_fn(resp);
>>          break;
>>      }
>>
>> diff --git a/risu.c b/risu.c
>> index a10422a..88e586c 100644
>> --- a/risu.c
>> +++ b/risu.c
>> @@ -37,9 +37,28 @@ sigjmp_buf jmpbuf;
>>  /* Should we test for FP exception status bits? */
>>  int test_fp_exc;
>>
>> +/* Master functions */
>> +
>> +int read_sock(void *ptr, size_t bytes)
>> +{
>> +    return recv_data_pkt(master_socket, ptr, bytes);
>> +}
>> +
>> +void respond_sock(int r)
>> +{
>> +    send_response_byte(master_socket, r);
>> +}
>> +
>> +/* Apprentice function */
>> +
>> +int write_sock(void *ptr, size_t bytes)
>> +{
>> +    return send_data_pkt(apprentice_socket, ptr, bytes);
>> +}
>> +
>>  void master_sigill(int sig, siginfo_t *si, void *uc)
>>  {
>> -    switch (recv_and_compare_register_info(master_socket, uc)) {
>> +    switch (recv_and_compare_register_info(read_sock, respond_sock, uc)) {
>>      case 0:
>>          /* match OK */
>>          advance_pc(uc);
>> @@ -52,7 +71,7 @@ void master_sigill(int sig, siginfo_t *si, void *uc)
>>
>>  void apprentice_sigill(int sig, siginfo_t *si, void *uc)
>>  {
>> -    switch (send_register_info(apprentice_socket, uc)) {
>> +    switch (send_register_info(write_sock, uc)) {
>>      case 0:
>>          /* match OK */
>>          advance_pc(uc);
>> diff --git a/risu.h b/risu.h
>> index 78a7313..32241bc 100644
>> --- a/risu.h
>> +++ b/risu.h
>> @@ -53,17 +53,24 @@ struct reginfo;
>>
>>  /* Functions operating on reginfo */
>>
>> +/* To keep the read/write logic from multiplying across all arches
>> + * we wrap up the function here to keep all the changes in one place
>> + */
>
> Stale comment? The calling code is not per-arch any more.

Yes, I'll remove

>
>> +typedef int (*write_fn) (void *ptr, size_t bytes);
>> +typedef int (*read_fn) (void *ptr, size_t bytes);
>> +typedef void (*respond_fn) (int response);
>> +
>>  /* Send the register information from the struct ucontext down the socket.
>>   * Return the response code from the master.
>>   * NB: called from a signal handler.
>>   */
>> -int send_register_info(int sock, void *uc);
>> +int send_register_info(write_fn write_fn, void *uc);
>>
>>  /* Read register info from the socket and compare it with that from the
>>   * ucontext. Return 0 for match, 1 for end-of-test, 2 for mismatch.
>>   * NB: called from a signal handler.
>>   */
>> -int recv_and_compare_register_info(int sock, void *uc);
>> +int recv_and_compare_register_info(read_fn read_fn, respond_fn respond, 
>> void *uc);
>>
>>  /* Print a useful report on the status of the last comparison
>>   * done in recv_and_compare_register_info(). This is called on
>> --
>> 2.13.0
>>
>
> thanks
> -- PMM


--
Alex Bennée