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

[Cédric Le Goater]

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.

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;
+    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);
             return;
         }
-        len = init_sdrs[i + 4];
-        recid = init_sdrs[i] | (init_sdrs[i + 1] << 8);
+        sdrh = (struct ipmi_sdr_header *) &init_sdrs[i];
+        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);
             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
-- 
2.1.4