hw/cxl/mbox: Add support for background operations

Support background commands in the mailbox, and update
cmd_infostat_bg_op_sts() accordingly. This patch does not implement mbox
interrupts upon completion, so the kernel driver must rely on polling to
know when the operation is done.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Message-Id: <20231023160806.13206-12-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 91 insertions, 1 deletions

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index de63fc1a28..f1226f8f39 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -963,6 +963,8 @@ static CXLRetCode cmd_media_clear_poison(const struct cxl_cmd *cmd,
 #define IMMEDIATE_DATA_CHANGE (1 << 2)
 #define IMMEDIATE_POLICY_CHANGE (1 << 3)
 #define IMMEDIATE_LOG_CHANGE (1 << 4)
+#define SECURITY_STATE_CHANGE (1 << 5)
+#define BACKGROUND_OPERATION (1 << 6)
 
 static const struct cxl_cmd cxl_cmd_set[256][256] = {
     [EVENTS][GET_RECORDS] = { "EVENTS_GET_RECORDS",
@@ -1011,10 +1013,19 @@ static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
         cmd_get_physical_port_state, ~0, 0 },
 };
 
+/*
+ * While the command is executing in the background, the device should
+ * update the percentage complete in the Background Command Status Register
+ * at least once per second.
+ */
+
+#define CXL_MBOX_BG_UPDATE_FREQ 1000UL
+
 int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
                             size_t len_in, uint8_t *pl_in, size_t *len_out,
                             uint8_t *pl_out, bool *bg_started)
 {
+    int ret;
     const struct cxl_cmd *cxl_cmd;
     opcode_handler h;
 
@@ -1031,7 +1042,81 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
         return CXL_MBOX_INVALID_PAYLOAD_LENGTH;
     }
 
-    return (*h)(cxl_cmd, pl_in, len_in, pl_out, len_out, cci);
+    /* Only one bg command at a time */
+    if ((cxl_cmd->effect & BACKGROUND_OPERATION) &&
+        cci->bg.runtime > 0) {
+        return CXL_MBOX_BUSY;
+    }
+
+    ret = (*h)(cxl_cmd, pl_in, len_in, pl_out, len_out, cci);
+    if ((cxl_cmd->effect & BACKGROUND_OPERATION) &&
+        ret == CXL_MBOX_BG_STARTED) {
+        *bg_started = true;
+    } else {
+        *bg_started = false;
+    }
+
+    /* Set bg and the return code */
+    if (*bg_started) {
+        uint64_t now;
+
+        cci->bg.opcode = (set << 8) | cmd;
+
+        cci->bg.complete_pct = 0;
+        cci->bg.ret_code = 0;
+
+        now = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
+        cci->bg.starttime = now;
+        timer_mod(cci->bg.timer, now + CXL_MBOX_BG_UPDATE_FREQ);
+    }
+
+    return ret;
+}
+
+static void bg_timercb(void *opaque)
+{
+    CXLCCI *cci = opaque;
+    CXLDeviceState *cxl_dstate = &CXL_TYPE3(cci->d)->cxl_dstate;
+    uint64_t bg_status_reg = 0;
+    uint64_t now = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
+    uint64_t total_time = cci->bg.starttime + cci->bg.runtime;
+
+    assert(cci->bg.runtime > 0);
+    bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS,
+                               OP, cci->bg.opcode);
+
+    if (now >= total_time) { /* we are done */
+        uint64_t status_reg;
+        uint16_t ret = CXL_MBOX_SUCCESS;
+
+        cci->bg.complete_pct = 100;
+        /* Clear bg */
+        status_reg = FIELD_DP64(0, CXL_DEV_MAILBOX_STS, BG_OP, 0);
+        cxl_dstate->mbox_reg_state64[R_CXL_DEV_MAILBOX_STS] = status_reg;
+
+        bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS,
+                                   RET_CODE, ret);
+
+        /* TODO add ad-hoc cmd succesful completion handling */
+
+        qemu_log("Background command %04xh finished: %s\n",
+                 cci->bg.opcode,
+                 ret == CXL_MBOX_SUCCESS ? "success" : "aborted");
+    } else {
+        /* estimate only */
+        cci->bg.complete_pct = 100 * now / total_time;
+        timer_mod(cci->bg.timer, now + CXL_MBOX_BG_UPDATE_FREQ);
+    }
+
+    bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS,
+                               PERCENTAGE_COMP, cci->bg.complete_pct);
+    cxl_dstate->mbox_reg_state64[R_CXL_DEV_BG_CMD_STS] = bg_status_reg;
+
+    if (cci->bg.complete_pct == 100) {
+        cci->bg.starttime = 0;
+        /* registers are updated, allow new bg-capable cmds */
+        cci->bg.runtime = 0;
+    }
 }
 
 void cxl_init_cci(CXLCCI *cci, size_t payload_max)
@@ -1050,6 +1135,11 @@ void cxl_init_cci(CXLCCI *cci, size_t payload_max)
             }
         }
     }
+    cci->bg.complete_pct = 0;
+    cci->bg.starttime = 0;
+    cci->bg.runtime = 0;
+    cci->bg.timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
+                                 bg_timercb, cci);
 }
 
 void cxl_initialize_mailbox_swcci(CXLCCI *cci, DeviceState *intf,