hw/cxl/events: Wire up get/clear event mailbox commands

CXL testing is benefited from an artificial event log injection
mechanism.

Add an event log infrastructure to insert, get, and clear events from
the various logs available on a device.

Replace the stubbed out CXL Get/Clear Event mailbox commands with
commands that operate on the new infrastructure.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230530133603.16934-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

3 files changed, 256 insertions, 2 deletions

diff --git a/hw/cxl/cxl-events.c b/hw/cxl/cxl-events.c
new file mode 100644
index 0000000000..5da1b76b97
--- /dev/null
+++ b/hw/cxl/cxl-events.c
@@ -0,0 +1,217 @@
+/*
+ * CXL Event processing
+ *
+ * Copyright(C) 2023 Intel Corporation.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See the
+ * COPYING file in the top-level directory.
+ */
+
+#include <stdint.h>
+
+#include "qemu/osdep.h"
+#include "qemu/bswap.h"
+#include "qemu/typedefs.h"
+#include "qemu/error-report.h"
+#include "hw/cxl/cxl.h"
+#include "hw/cxl/cxl_events.h"
+
+/* Artificial limit on the number of events a log can hold */
+#define CXL_TEST_EVENT_OVERFLOW 8
+
+static void reset_overflow(CXLEventLog *log)
+{
+    log->overflow_err_count = 0;
+    log->first_overflow_timestamp = 0;
+    log->last_overflow_timestamp = 0;
+}
+
+void cxl_event_init(CXLDeviceState *cxlds)
+{
+    CXLEventLog *log;
+    int i;
+
+    for (i = 0; i < CXL_EVENT_TYPE_MAX; i++) {
+        log = &cxlds->event_logs[i];
+        log->next_handle = 1;
+        log->overflow_err_count = 0;
+        log->first_overflow_timestamp = 0;
+        log->last_overflow_timestamp = 0;
+        qemu_mutex_init(&log->lock);
+        QSIMPLEQ_INIT(&log->events);
+    }
+}
+
+static CXLEvent *cxl_event_get_head(CXLEventLog *log)
+{
+    return QSIMPLEQ_FIRST(&log->events);
+}
+
+static CXLEvent *cxl_event_get_next(CXLEvent *entry)
+{
+    return QSIMPLEQ_NEXT(entry, node);
+}
+
+static int cxl_event_count(CXLEventLog *log)
+{
+    CXLEvent *event;
+    int rc = 0;
+
+    QSIMPLEQ_FOREACH(event, &log->events, node) {
+        rc++;
+    }
+
+    return rc;
+}
+
+static bool cxl_event_empty(CXLEventLog *log)
+{
+    return QSIMPLEQ_EMPTY(&log->events);
+}
+
+static void cxl_event_delete_head(CXLDeviceState *cxlds,
+                                  CXLEventLogType log_type,
+                                  CXLEventLog *log)
+{
+    CXLEvent *entry = cxl_event_get_head(log);
+
+    reset_overflow(log);
+    QSIMPLEQ_REMOVE_HEAD(&log->events, node);
+    if (cxl_event_empty(log)) {
+        cxl_event_set_status(cxlds, log_type, false);
+    }
+    g_free(entry);
+}
+
+/*
+ * return true if an interrupt should be generated as a result
+ * of inserting this event.
+ */
+bool cxl_event_insert(CXLDeviceState *cxlds, CXLEventLogType log_type,
+                      CXLEventRecordRaw *event)
+{
+    uint64_t time;
+    CXLEventLog *log;
+    CXLEvent *entry;
+
+    if (log_type >= CXL_EVENT_TYPE_MAX) {
+        return false;
+    }
+
+    time = cxl_device_get_timestamp(cxlds);
+
+    log = &cxlds->event_logs[log_type];
+
+    QEMU_LOCK_GUARD(&log->lock);
+
+    if (cxl_event_count(log) >= CXL_TEST_EVENT_OVERFLOW) {
+        if (log->overflow_err_count == 0) {
+            log->first_overflow_timestamp = time;
+        }
+        log->overflow_err_count++;
+        log->last_overflow_timestamp = time;
+        return false;
+    }
+
+    entry = g_new0(CXLEvent, 1);
+
+    memcpy(&entry->data, event, sizeof(*event));
+
+    entry->data.hdr.handle = cpu_to_le16(log->next_handle);
+    log->next_handle++;
+    /* 0 handle is never valid */
+    if (log->next_handle == 0) {
+        log->next_handle++;
+    }
+    entry->data.hdr.timestamp = cpu_to_le64(time);
+
+    QSIMPLEQ_INSERT_TAIL(&log->events, entry, node);
+    cxl_event_set_status(cxlds, log_type, true);
+
+    /* Count went from 0 to 1 */
+    return cxl_event_count(log) == 1;
+}
+
+CXLRetCode cxl_event_get_records(CXLDeviceState *cxlds, CXLGetEventPayload *pl,
+                                 uint8_t log_type, int max_recs,
+                                 uint16_t *len)
+{
+    CXLEventLog *log;
+    CXLEvent *entry;
+    uint16_t nr;
+
+    if (log_type >= CXL_EVENT_TYPE_MAX) {
+        return CXL_MBOX_INVALID_INPUT;
+    }
+
+    log = &cxlds->event_logs[log_type];
+
+    QEMU_LOCK_GUARD(&log->lock);
+
+    entry = cxl_event_get_head(log);
+    for (nr = 0; entry && nr < max_recs; nr++) {
+        memcpy(&pl->records[nr], &entry->data, CXL_EVENT_RECORD_SIZE);
+        entry = cxl_event_get_next(entry);
+    }
+
+    if (!cxl_event_empty(log)) {
+        pl->flags |= CXL_GET_EVENT_FLAG_MORE_RECORDS;
+    }
+
+    if (log->overflow_err_count) {
+        pl->flags |= CXL_GET_EVENT_FLAG_OVERFLOW;
+        pl->overflow_err_count = cpu_to_le16(log->overflow_err_count);
+        pl->first_overflow_timestamp = cpu_to_le64(log->first_overflow_timestamp);
+        pl->last_overflow_timestamp = cpu_to_le64(log->last_overflow_timestamp);
+    }
+
+    pl->record_count = cpu_to_le16(nr);
+    *len = CXL_EVENT_PAYLOAD_HDR_SIZE + (CXL_EVENT_RECORD_SIZE * nr);
+
+    return CXL_MBOX_SUCCESS;
+}
+
+CXLRetCode cxl_event_clear_records(CXLDeviceState *cxlds, CXLClearEventPayload *pl)
+{
+    CXLEventLog *log;
+    uint8_t log_type;
+    CXLEvent *entry;
+    int nr;
+
+    log_type = pl->event_log;
+
+    if (log_type >= CXL_EVENT_TYPE_MAX) {
+        return CXL_MBOX_INVALID_INPUT;
+    }
+
+    log = &cxlds->event_logs[log_type];
+
+    QEMU_LOCK_GUARD(&log->lock);
+    /*
+     * Must itterate the queue twice.
+     * "The device shall verify the event record handles specified in the input
+     * payload are in temporal order. If the device detects an older event
+     * record that will not be cleared when Clear Event Records is executed,
+     * the device shall return the Invalid Handle return code and shall not
+     * clear any of the specified event records."
+     *   -- CXL 3.0 8.2.9.2.3
+     */
+    entry = cxl_event_get_head(log);
+    for (nr = 0; entry && nr < pl->nr_recs; nr++) {
+        uint16_t handle = pl->handle[nr];
+
+        /* NOTE: Both handles are little endian. */
+        if (handle == 0 || entry->data.hdr.handle != handle) {
+            return CXL_MBOX_INVALID_INPUT;
+        }
+        entry = cxl_event_get_next(entry);
+    }
+
+    entry = cxl_event_get_head(log);
+    for (nr = 0; entry && nr < pl->nr_recs; nr++) {
+        cxl_event_delete_head(cxlds, log_type, log);
+        entry = cxl_event_get_head(log);
+    }
+
+    return CXL_MBOX_SUCCESS;
+}
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index d7e114aaae..3f46538048 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -9,6 +9,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/cxl/cxl.h"
+#include "hw/cxl/cxl_events.h"
 #include "hw/pci/pci.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"
@@ -95,11 +96,46 @@ struct cxl_cmd {
         return CXL_MBOX_SUCCESS;                                          \
     }
 
-DEFINE_MAILBOX_HANDLER_ZEROED(events_get_records, 0x20);
-DEFINE_MAILBOX_HANDLER_NOP(events_clear_records);
 DEFINE_MAILBOX_HANDLER_ZEROED(events_get_interrupt_policy, 4);
 DEFINE_MAILBOX_HANDLER_NOP(events_set_interrupt_policy);
 
+static CXLRetCode cmd_events_get_records(struct cxl_cmd *cmd,
+                                         CXLDeviceState *cxlds,
+                                         uint16_t *len)
+{
+    CXLGetEventPayload *pl;
+    uint8_t log_type;
+    int max_recs;
+
+    if (cmd->in < sizeof(log_type)) {
+        return CXL_MBOX_INVALID_INPUT;
+    }
+
+    log_type = *((uint8_t *)cmd->payload);
+
+    pl = (CXLGetEventPayload *)cmd->payload;
+    memset(pl, 0, sizeof(*pl));
+
+    max_recs = (cxlds->payload_size - CXL_EVENT_PAYLOAD_HDR_SIZE) /
+                CXL_EVENT_RECORD_SIZE;
+    if (max_recs > 0xFFFF) {
+        max_recs = 0xFFFF;
+    }
+
+    return cxl_event_get_records(cxlds, pl, log_type, max_recs, len);
+}
+
+static CXLRetCode cmd_events_clear_records(struct cxl_cmd *cmd,
+                                           CXLDeviceState *cxlds,
+                                           uint16_t *len)
+{
+    CXLClearEventPayload *pl;
+
+    pl = (CXLClearEventPayload *)cmd->payload;
+    *len = 0;
+    return cxl_event_clear_records(cxlds, pl);
+}
+
 /* 8.2.9.2.1 */
 static CXLRetCode cmd_firmware_update_get_info(struct cxl_cmd *cmd,
                                                CXLDeviceState *cxl_dstate,
diff --git a/hw/cxl/meson.build b/hw/cxl/meson.build
index 1f9aa2ea1f..e261ff3881 100644
--- a/hw/cxl/meson.build
+++ b/hw/cxl/meson.build
@@ -5,6 +5,7 @@ system_ss.add(when: 'CONFIG_CXL',
                    'cxl-mailbox-utils.c',
                    'cxl-host.c',
                    'cxl-cdat.c',
+                   'cxl-events.c',
                ),
                if_false: files(
                    'cxl-host-stubs.c',