Re: [Qemu-devel] [PATCH v2 4/9] ipmi: introduce a struct ipmi_sdr_compact

[Greg Kurz]

On Thu, 21 Jan 2016 18:18:49 +0100
Cédric Le Goater <address@hidden> wrote:

> Currently, sdr attributes are identified using byte offsets and this
> can be a bit confusing.
> 
> This patch adds a struct ipmi_sdr_compact conforming to the IPMI specs
> and replaces byte offsets with names. It also introduces and uses a
> struct ipmi_sdr_header in sections of the code where no assumption is
> made on the type of SDR. This leave rooms to potential usage of other
> types in the future.
> 

Turning all these magic numbers into understandable names is definitely a
great idea !

See comments below.

> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
>  hw/ipmi/ipmi_bmc_sim.c | 65 
> +++++++++++++++++++++++++++++++-------------------
>  include/hw/ipmi/ipmi.h | 44 ++++++++++++++++++++++++++++++++++
>  2 files changed, 84 insertions(+), 25 deletions(-)
> 
> diff --git a/hw/ipmi/ipmi_bmc_sim.c b/hw/ipmi/ipmi_bmc_sim.c
> index fc596a548df7..31f990199154 100644
> --- a/hw/ipmi/ipmi_bmc_sim.c
> +++ b/hw/ipmi/ipmi_bmc_sim.c
> @@ -323,11 +323,15 @@ static void sdr_inc_reservation(IPMISdr *sdr)
>  static int sdr_add_entry(IPMIBmcSim *ibs, const uint8_t *entry,
>                           unsigned int len, uint16_t *recid)
>  {
> +    struct ipmi_sdr_header *sdrh_entry = (struct ipmi_sdr_header *) entry;

This looks like the entry argument should be struct ipmi_sdr_header * and
you would not need sdrh_entry.

> +    struct ipmi_sdr_header *sdrh =
> +        (struct ipmi_sdr_header *) &ibs->sdr.sdr[ibs->sdr.next_free];
> +
>      if ((len < 5) || (len > 255)) {
>          return 1;
>      }
> 
> -    if (entry[4] != len - 5) {
> +    if (sdrh_entry->rec_length != len - 5) {
>          return 1;
>      }
> 
> @@ -336,10 +340,10 @@ static int sdr_add_entry(IPMIBmcSim *ibs, const uint8_t 
> *entry,
>          return 1;
>      }
> 
> -    memcpy(ibs->sdr.sdr + ibs->sdr.next_free, entry, len);
> -    ibs->sdr.sdr[ibs->sdr.next_free] = ibs->sdr.next_rec_id & 0xff;
> -    ibs->sdr.sdr[ibs->sdr.next_free+1] = (ibs->sdr.next_rec_id >> 8) & 0xff;
> -    ibs->sdr.sdr[ibs->sdr.next_free+2] = 0x51; /* Conform to IPMI 1.5 spec */
> +    memcpy(sdrh, entry, len);
> +    sdrh->rec_id[0] = ibs->sdr.next_rec_id & 0xff;
> +    sdrh->rec_id[1] = (ibs->sdr.next_rec_id >> 8) & 0xff;
> +    sdrh->sdr_version = 0x51; /* Conform to IPMI 1.5 spec */
> 
>      if (recid) {
>          *recid = ibs->sdr.next_rec_id;
> @@ -357,8 +361,10 @@ static int sdr_find_entry(IPMISdr *sdr, uint16_t recid,
>      unsigned int pos = *retpos;
> 
>      while (pos < sdr->next_free) {
> -        uint16_t trec = sdr->sdr[pos] | (sdr->sdr[pos + 1] << 8);
> -        unsigned int nextpos = pos + sdr->sdr[pos + 4];
> +        struct ipmi_sdr_header *sdrh =
> +            (struct ipmi_sdr_header *) &sdr->sdr[pos];
> +        uint16_t trec = ipmi_sdr_recid(sdrh);
> +        unsigned int nextpos = pos + sdrh->rec_length;
> 
>          if (trec == recid) {
>              if (nextrec) {
> @@ -507,29 +513,32 @@ static void ipmi_init_sensors_from_sdrs(IPMIBmcSim *s)
> 
>      pos = 0;
>      for (i = 0; !sdr_find_entry(&s->sdr, i, &pos, NULL); i++) {
> -        uint8_t *sdr = s->sdr.sdr + pos;
> -        unsigned int len = sdr[4];
> +        struct ipmi_sdr_compact *sdr =
> +            (struct ipmi_sdr_compact *) &s->sdr.sdr[pos];
> +        unsigned int len = sdr->header.rec_length;
> 
>          if (len < 20) {
>              continue;
>          }
> -        if ((sdr[3] < 1) || (sdr[3] > 2)) {
> +        if (sdr->header.rec_type != IPMI_SDR_COMPACT_TYPE) {
>              continue; /* Not a sensor SDR we set from */
>          }
> 
> -        if (sdr[7] > MAX_SENSORS) {
> +        if (sdr->sensor_owner_number > MAX_SENSORS) {
>              continue;
>          }
> -        sens = s->sensors + sdr[7];
> +        sens = s->sensors + sdr->sensor_owner_number;
> 
>          IPMI_SENSOR_SET_PRESENT(sens, 1);
> -        IPMI_SENSOR_SET_SCAN_ON(sens, (sdr[10] >> 6) & 1);
> -        IPMI_SENSOR_SET_EVENTS_ON(sens, (sdr[10] >> 5) & 1);
> -        sens->assert_suppt = sdr[14] | (sdr[15] << 8);
> -        sens->deassert_suppt = sdr[16] | (sdr[17] << 8);
> -        sens->states_suppt = sdr[18] | (sdr[19] << 8);
> -        sens->sensor_type = sdr[12];
> -        sens->evt_reading_type_code = sdr[13] & 0x7f;
> +        IPMI_SENSOR_SET_SCAN_ON(sens, (sdr->sensor_init >> 6) & 1);
> +        IPMI_SENSOR_SET_EVENTS_ON(sens, (sdr->sensor_init >> 5) & 1);
> +        sens->assert_suppt = sdr->assert_mask[0] | (sdr->assert_mask[1] << 
> 8);
> +        sens->deassert_suppt =
> +            sdr->deassert_mask[0] | (sdr->deassert_mask[1] << 8);
> +        sens->states_suppt =
> +            sdr->discrete_mask[0] | (sdr->discrete_mask[1] << 8);
> +        sens->sensor_type = sdr->sensor_type;
> +        sens->evt_reading_type_code = sdr->reading_type & 0x7f;
> 
>          /* Enable all the events that are supported. */
>          sens->assert_enable = sens->assert_suppt;
> @@ -1155,6 +1164,7 @@ static void get_sdr(IPMIBmcSim *ibs,
>  {
>      unsigned int pos;
>      uint16_t nextrec;
> +    struct ipmi_sdr_header *sdrh;
> 
>      IPMI_CHECK_CMD_LEN(8);
>      if (cmd[6]) {
> @@ -1166,7 +1176,10 @@ static void get_sdr(IPMIBmcSim *ibs,
>          rsp[2] = IPMI_CC_REQ_ENTRY_NOT_PRESENT;
>          return;
>      }
> -    if (cmd[6] > (ibs->sdr.sdr[pos + 4])) {
> +
> +    sdrh = (struct ipmi_sdr_header *) &ibs->sdr.sdr[pos];
> +
> +    if (cmd[6] > sdrh->rec_length) {
>          rsp[2] = IPMI_CC_PARM_OUT_OF_RANGE;
>          return;
>      }
> @@ -1175,7 +1188,7 @@ static void get_sdr(IPMIBmcSim *ibs,
>      IPMI_ADD_RSP_DATA((nextrec >> 8) & 0xff);
> 
>      if (cmd[7] == 0xff) {
> -        cmd[7] = ibs->sdr.sdr[pos + 4] - cmd[6];
> +        cmd[7] = sdrh->rec_length - cmd[6];
>      }
> 
>      if ((cmd[7] + *rsp_len) > max_rsp_len) {
> @@ -1644,18 +1657,20 @@ static void ipmi_sim_init(Object *obj)
>      }
> 
>      for (i = 0;;) {
> +        struct ipmi_sdr_header *sdrh;
>          int len;
>          if ((i + 5) > sizeof(init_sdrs)) {
> -            error_report("Problem with recid 0x%4.4x: \n", i);
> +            error_report("Problem with recid 0x%4.4x", i);

Unrelated change.

>              return;
>          }
> -        len = init_sdrs[i + 4];
> -        recid = init_sdrs[i] | (init_sdrs[i + 1] << 8);
> +        sdrh = (struct ipmi_sdr_header *) &init_sdrs[i];

Maybe init_sdrs could be turned into something which already has explicit
struct ipmi_sdr_header fields ?

> +        len = sdrh->rec_length;
> +        recid = ipmi_sdr_recid(sdrh);
>          if (recid == 0xffff) {
>              break;
>          }
>          if ((i + len + 5) > sizeof(init_sdrs)) {
> -            error_report("Problem with recid 0x%4.4x\n", i);
> +            error_report("Problem with recid 0x%4.4x", i);

Unrelated change.

>              return;
>          }
>          sdr_add_entry(ibs, init_sdrs + i, len, NULL);
> diff --git a/include/hw/ipmi/ipmi.h b/include/hw/ipmi/ipmi.h
> index 32bac0fa8877..7e142e241dcb 100644
> --- a/include/hw/ipmi/ipmi.h
> +++ b/include/hw/ipmi/ipmi.h
> @@ -210,4 +210,48 @@ IPMIFwInfo *ipmi_next_fwinfo(IPMIFwInfo *current);
>  #define ipmi_debug(fs, ...)
>  #endif
> 
> +struct ipmi_sdr_header {
> +    uint8_t  rec_id[2];
> +    uint8_t  sdr_version;               /* 0x51 */
> +    uint8_t  rec_type;
> +    uint8_t  rec_length;
> +};
> +#define IPMI_SDR_HEADER_SIZE     sizeof(struct ipmi_sdr_header)
> +
> +#define ipmi_sdr_recid(sdr) ((sdr)->rec_id[0] | ((sdr)->rec_id[1] << 8))
> +
> +/*
> + * 43.2 SDR Type 02h. Compact Sensor Record
> + */
> +#define IPMI_SDR_COMPACT_TYPE    2
> +
> +struct ipmi_sdr_compact {
> +    struct ipmi_sdr_header header;
> +
> +    uint8_t  sensor_owner_id;
> +    uint8_t  sensor_owner_lun;
> +    uint8_t  sensor_owner_number;       /* byte 8 */
> +    uint8_t  entity_id;
> +    uint8_t  entity_instance;
> +    uint8_t  sensor_init;
> +    uint8_t  sensor_caps;
> +    uint8_t  sensor_type;
> +    uint8_t  reading_type;
> +    uint8_t  assert_mask[2];            /* byte 16 */
> +    uint8_t  deassert_mask[2];
> +    uint8_t  discrete_mask[2];
> +    uint8_t  sensor_unit1;
> +    uint8_t  sensor_unit2;
> +    uint8_t  sensor_unit3;
> +    uint8_t  sensor_direction[2];       /* byte 24 */
> +    uint8_t  positive_threshold;
> +    uint8_t  negative_threshold;
> +    uint8_t  reserved[3];
> +    uint8_t  oem;
> +    uint8_t  id_str_len;                /* byte 32 */
> +    uint8_t  id_string[16];
> +};
> +
> +typedef uint8_t ipmi_sdr_compact_buffer[sizeof(struct ipmi_sdr_compact)];
> +
>  #endif