[PATCH 3/3] ipmi/bmc-sim: Add 'Get Channel Info' command

[Nicholas Piggin <npiggin@gmail.com>]

Linux issues this command when booting a powernv machine.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 include/hw/ipmi/ipmi.h | 14 +++++++++++
 hw/ipmi/ipmi_bmc_sim.c | 56 ++++++++++++++++++++++++++++++++++++++++--
 hw/ipmi/ipmi_bt.c      |  2 ++
 hw/ipmi/ipmi_kcs.c     |  1 +
 4 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/include/hw/ipmi/ipmi.h b/include/hw/ipmi/ipmi.h
index 77a7213ed93..5f01a50cd86 100644
--- a/include/hw/ipmi/ipmi.h
+++ b/include/hw/ipmi/ipmi.h
@@ -41,6 +41,15 @@ enum ipmi_op {
     IPMI_SEND_NMI
 };
 
+/* Channel properties */
+#define IPMI_CHANNEL_IPMB                0x00
+#define IPMI_CHANNEL_SYSTEM              0x0f
+#define IPMI_CH_MEDIUM_IPMB              0x01
+#define IPMI_CH_MEDIUM_SYSTEM            0x0c
+#define IPMI_CH_PROTOCOL_IPMB            0x01
+#define IPMI_CH_PROTOCOL_KCS             0x05
+#define IPMI_CH_PROTOCOL_BT_15           0x08
+
 #define IPMI_CC_INVALID_CMD                              0xc1
 #define IPMI_CC_COMMAND_INVALID_FOR_LUN                  0xc2
 #define IPMI_CC_TIMEOUT                                  0xc3
@@ -170,6 +179,11 @@ struct IPMIInterfaceClass {
      * Return the firmware info for a device.
      */
     void (*get_fwinfo)(struct IPMIInterface *s, IPMIFwInfo *info);
+
+    /*
+     * IPMI channel protocol type number.
+     */
+    uint8_t protocol;
 };
 
 /*
diff --git a/hw/ipmi/ipmi_bmc_sim.c b/hw/ipmi/ipmi_bmc_sim.c
index 8c3313aa65f..9198f854bd9 100644
--- a/hw/ipmi/ipmi_bmc_sim.c
+++ b/hw/ipmi/ipmi_bmc_sim.c
@@ -70,6 +70,7 @@
 #define IPMI_CMD_GET_MSG                  0x33
 #define IPMI_CMD_SEND_MSG                 0x34
 #define IPMI_CMD_READ_EVT_MSG_BUF         0x35
+#define IPMI_CMD_GET_CHANNEL_INFO         0x42
 
 #define IPMI_NETFN_STORAGE            0x0a
 
@@ -1033,8 +1034,8 @@ static void send_msg(IPMIBmcSim *ibs,
     uint8_t *buf;
     uint8_t netfn, rqLun, rsLun, rqSeq;
 
-    if (cmd[2] != 0) {
-        /* We only handle channel 0 with no options */
+    if (cmd[2] != IPMI_CHANNEL_IPMB) {
+        /* We only handle channel 0h (IPMB) with no options */
         rsp_buffer_set_error(rsp, IPMI_CC_INVALID_DATA_FIELD);
         return;
     }
@@ -1232,6 +1233,56 @@ static void get_watchdog_timer(IPMIBmcSim *ibs,
     }
 }
 
+static void get_channel_info(IPMIBmcSim *ibs,
+                             uint8_t *cmd, unsigned int cmd_len,
+                             RspBuffer *rsp)
+{
+    IPMIInterface *s = ibs->parent.intf;
+    IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
+    uint8_t ch = cmd[1] & 0x0f;
+
+    /* Only define channel 0h (IPMB) and Fh (system interface) */
+
+    if (ch == 0x0e) { /* "This channel" */
+        ch = IPMI_CHANNEL_SYSTEM;
+    }
+    rsp_buffer_push(rsp, ch);
+
+    if (ch != IPMI_CHANNEL_IPMB && ch != IPMI_CHANNEL_SYSTEM) {
+        /* Not supported */
+        int i;
+        for (i = 0; i < 8; i++) {
+            rsp_buffer_push(rsp, 0x00);
+        }
+        return;
+    }
+
+    if (ch == IPMI_CHANNEL_IPMB) {
+        rsp_buffer_push(rsp, IPMI_CH_MEDIUM_IPMB);
+        rsp_buffer_push(rsp, IPMI_CH_PROTOCOL_IPMB);
+    } else { /* IPMI_CHANNEL_SYSTEM */
+        rsp_buffer_push(rsp, IPMI_CH_MEDIUM_SYSTEM);
+        rsp_buffer_push(rsp, k->protocol);
+    }
+
+    rsp_buffer_push(rsp, 0x00); /* Session-less */
+
+    /* IPMI Vendor ID */
+    rsp_buffer_push(rsp, 0xf2);
+    rsp_buffer_push(rsp, 0x1b);
+    rsp_buffer_push(rsp, 0x00);
+
+    if (ch == IPMI_CHANNEL_SYSTEM) {
+        /* IRQ assigned by ACPI/PnP (XXX?) */
+        rsp_buffer_push(rsp, 0x60);
+        rsp_buffer_push(rsp, 0x60);
+    } else {
+        /* Reserved */
+        rsp_buffer_push(rsp, 0x00);
+        rsp_buffer_push(rsp, 0x00);
+    }
+}
+
 static void get_sdr_rep_info(IPMIBmcSim *ibs,
                              uint8_t *cmd, unsigned int cmd_len,
                              RspBuffer *rsp)
@@ -2028,6 +2079,7 @@ static const IPMICmdHandler app_cmds[] = {
     [IPMI_CMD_RESET_WATCHDOG_TIMER] = { reset_watchdog_timer },
     [IPMI_CMD_SET_WATCHDOG_TIMER] = { set_watchdog_timer, 8 },
     [IPMI_CMD_GET_WATCHDOG_TIMER] = { get_watchdog_timer },
+    [IPMI_CMD_GET_CHANNEL_INFO] = { get_channel_info, 3 },
 };
 static const IPMINetfn app_netfn = {
     .cmd_nums = ARRAY_SIZE(app_cmds),
diff --git a/hw/ipmi/ipmi_bt.c b/hw/ipmi/ipmi_bt.c
index 583fc64730c..d639c151c4d 100644
--- a/hw/ipmi/ipmi_bt.c
+++ b/hw/ipmi/ipmi_bt.c
@@ -434,4 +434,6 @@ void ipmi_bt_class_init(IPMIInterfaceClass *iic)
     iic->handle_if_event = ipmi_bt_handle_event;
     iic->set_irq_enable = ipmi_bt_set_irq_enable;
     iic->reset = ipmi_bt_handle_reset;
+    /* BT System Interface Format, IPMI v1.5 */
+    iic->protocol = IPMI_CH_PROTOCOL_BT_15;
 }
diff --git a/hw/ipmi/ipmi_kcs.c b/hw/ipmi/ipmi_kcs.c
index c15977cab4c..8af7698286d 100644
--- a/hw/ipmi/ipmi_kcs.c
+++ b/hw/ipmi/ipmi_kcs.c
@@ -420,4 +420,5 @@ void ipmi_kcs_class_init(IPMIInterfaceClass *iic)
     iic->handle_rsp = ipmi_kcs_handle_rsp;
     iic->handle_if_event = ipmi_kcs_handle_event;
     iic->set_irq_enable = ipmi_kcs_set_irq_enable;
+    iic->protocol = IPMI_CH_PROTOCOL_KCS;
 }
-- 
2.47.1