hw/block/nvme: add support for the asynchronous event request command

Add support for the Asynchronous Event Request command. Required for
compliance with NVMe revision 1.3d. See NVM Express 1.3d, Section 5.2
("Asynchronous Event Request command").

Mostly imported from Keith's qemu-nvme tree. Modified with a max number
of queued events (controllable with the aer_max_queued device
parameter). The spec states that the controller *should* retain
events, so we do best effort here.

Signed-off-by: Klaus Jensen <klaus.jensen@cnexlabs.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Acked-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Message-Id: <20200706061303.246057-9-its@irrelevant.dk>

3 files changed, 221 insertions, 8 deletions

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 7395819..41a15da 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -20,7 +20,8 @@
  *      -device nvme,drive=<drive_id>,serial=<serial>,id=<id[optional]>, \
  *              cmb_size_mb=<cmb_size_mb[optional]>, \
  *              [pmrdev=<mem_backend_file_id>,] \
- *              max_ioqpairs=<N[optional]>
+ *              max_ioqpairs=<N[optional]>, \
+ *              aerl=<N[optional]>, aer_max_queued=<N[optional]>
  *
  * Note cmb_size_mb denotes size of CMB in MB. CMB is assumed to be at
  * offset 0 in BAR2 and supports only WDS, RDS and SQS for now.
@@ -32,6 +33,20 @@
  * For example:
  * -object memory-backend-file,id=<mem_id>,share=on,mem-path=<file_path>, \
  *  size=<size> .... -device nvme,...,pmrdev=<mem_id>
+ *
+ *
+ * nvme device parameters
+ * ~~~~~~~~~~~~~~~~~~~~~~
+ * - `aerl`
+ *   The Asynchronous Event Request Limit (AERL). Indicates the maximum number
+ *   of concurrently outstanding Asynchronous Event Request commands suppoert
+ *   by the controller. This is a 0's based value.
+ *
+ * - `aer_max_queued`
+ *   This is the maximum number of events that the device will enqueue for
+ *   completion when there are no oustanding AERs. When the maximum number of
+ *   enqueued events are reached, subsequent events will be dropped.
+ *
  */
 
 #include "qemu/osdep.h"
@@ -355,6 +370,85 @@ static void nvme_enqueue_req_completion(NvmeCQueue *cq, NvmeRequest *req)
     timer_mod(cq->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 500);
 }
 
+static void nvme_process_aers(void *opaque)
+{
+    NvmeCtrl *n = opaque;
+    NvmeAsyncEvent *event, *next;
+
+    trace_pci_nvme_process_aers(n->aer_queued);
+
+    QTAILQ_FOREACH_SAFE(event, &n->aer_queue, entry, next) {
+        NvmeRequest *req;
+        NvmeAerResult *result;
+
+        /* can't post cqe if there is nothing to complete */
+        if (!n->outstanding_aers) {
+            trace_pci_nvme_no_outstanding_aers();
+            break;
+        }
+
+        /* ignore if masked (cqe posted, but event not cleared) */
+        if (n->aer_mask & (1 << event->result.event_type)) {
+            trace_pci_nvme_aer_masked(event->result.event_type, n->aer_mask);
+            continue;
+        }
+
+        QTAILQ_REMOVE(&n->aer_queue, event, entry);
+        n->aer_queued--;
+
+        n->aer_mask |= 1 << event->result.event_type;
+        n->outstanding_aers--;
+
+        req = n->aer_reqs[n->outstanding_aers];
+
+        result = (NvmeAerResult *) &req->cqe.result;
+        result->event_type = event->result.event_type;
+        result->event_info = event->result.event_info;
+        result->log_page = event->result.log_page;
+        g_free(event);
+
+        req->status = NVME_SUCCESS;
+
+        trace_pci_nvme_aer_post_cqe(result->event_type, result->event_info,
+                                    result->log_page);
+
+        nvme_enqueue_req_completion(&n->admin_cq, req);
+    }
+}
+
+static void nvme_enqueue_event(NvmeCtrl *n, uint8_t event_type,
+                               uint8_t event_info, uint8_t log_page)
+{
+    NvmeAsyncEvent *event;
+
+    trace_pci_nvme_enqueue_event(event_type, event_info, log_page);
+
+    if (n->aer_queued == n->params.aer_max_queued) {
+        trace_pci_nvme_enqueue_event_noqueue(n->aer_queued);
+        return;
+    }
+
+    event = g_new(NvmeAsyncEvent, 1);
+    event->result = (NvmeAerResult) {
+        .event_type = event_type,
+        .event_info = event_info,
+        .log_page   = log_page,
+    };
+
+    QTAILQ_INSERT_TAIL(&n->aer_queue, event, entry);
+    n->aer_queued++;
+
+    nvme_process_aers(n);
+}
+
+static void nvme_clear_events(NvmeCtrl *n, uint8_t event_type)
+{
+    n->aer_mask &= ~(1 << event_type);
+    if (!QTAILQ_EMPTY(&n->aer_queue)) {
+        nvme_process_aers(n);
+    }
+}
+
 static void nvme_rw_cb(void *opaque, int ret)
 {
     NvmeRequest *req = opaque;
@@ -605,8 +699,9 @@ static uint16_t nvme_create_sq(NvmeCtrl *n, NvmeCmd *cmd)
     return NVME_SUCCESS;
 }
 
-static uint16_t nvme_smart_info(NvmeCtrl *n, NvmeCmd *cmd, uint32_t buf_len,
-                                uint64_t off, NvmeRequest *req)
+static uint16_t nvme_smart_info(NvmeCtrl *n, NvmeCmd *cmd, uint8_t rae,
+                                uint32_t buf_len, uint64_t off,
+                                NvmeRequest *req)
 {
     uint64_t prp1 = le64_to_cpu(cmd->dptr.prp1);
     uint64_t prp2 = le64_to_cpu(cmd->dptr.prp2);
@@ -655,6 +750,10 @@ static uint16_t nvme_smart_info(NvmeCtrl *n, NvmeCmd *cmd, uint32_t buf_len,
     smart.power_on_hours[0] =
         cpu_to_le64((((current_ms - n->starttime_ms) / 1000) / 60) / 60);
 
+    if (!rae) {
+        nvme_clear_events(n, NVME_AER_TYPE_SMART);
+    }
+
     return nvme_dma_read_prp(n, (uint8_t *) &smart + off, trans_len, prp1,
                              prp2);
 }
@@ -681,14 +780,19 @@ static uint16_t nvme_fw_log_info(NvmeCtrl *n, NvmeCmd *cmd, uint32_t buf_len,
                              prp2);
 }
 
-static uint16_t nvme_error_info(NvmeCtrl *n, NvmeCmd *cmd, uint32_t buf_len,
-                                uint64_t off, NvmeRequest *req)
+static uint16_t nvme_error_info(NvmeCtrl *n, NvmeCmd *cmd, uint8_t rae,
+                                uint32_t buf_len, uint64_t off,
+                                NvmeRequest *req)
 {
     uint32_t trans_len;
     uint64_t prp1 = le64_to_cpu(cmd->dptr.prp1);
     uint64_t prp2 = le64_to_cpu(cmd->dptr.prp2);
     NvmeErrorLog errlog;
 
+    if (!rae) {
+        nvme_clear_events(n, NVME_AER_TYPE_ERROR);
+    }
+
     if (off > sizeof(errlog)) {
         return NVME_INVALID_FIELD | NVME_DNR;
     }
@@ -729,9 +833,9 @@ static uint16_t nvme_get_log(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 
     switch (lid) {
     case NVME_LOG_ERROR_INFO:
-        return nvme_error_info(n, cmd, len, off, req);
+        return nvme_error_info(n, cmd, rae, len, off, req);
     case NVME_LOG_SMART_INFO:
-        return nvme_smart_info(n, cmd, len, off, req);
+        return nvme_smart_info(n, cmd, rae, len, off, req);
     case NVME_LOG_FW_SLOT_INFO:
         return nvme_fw_log_info(n, cmd, len, off, req);
     default:
@@ -1013,6 +1117,9 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
             ((n->params.max_ioqpairs - 1) << 16);
         trace_pci_nvme_getfeat_numq(result);
         break;
+    case NVME_ASYNCHRONOUS_EVENT_CONF:
+        result = n->features.async_config;
+        break;
     case NVME_TIMESTAMP:
         return nvme_get_feature_timestamp(n, cmd);
     default:
@@ -1064,6 +1171,14 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
             return NVME_INVALID_FIELD | NVME_DNR;
         }
 
+        if (((n->temperature >= n->features.temp_thresh_hi) ||
+            (n->temperature <= n->features.temp_thresh_low)) &&
+            NVME_AEC_SMART(n->features.async_config) & NVME_SMART_TEMPERATURE) {
+            nvme_enqueue_event(n, NVME_AER_TYPE_SMART,
+                               NVME_AER_INFO_SMART_TEMP_THRESH,
+                               NVME_LOG_SMART_INFO);
+        }
+
         break;
     case NVME_VOLATILE_WRITE_CACHE:
         blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
@@ -1076,6 +1191,9 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
         req->cqe.result = cpu_to_le32((n->params.max_ioqpairs - 1) |
                                       ((n->params.max_ioqpairs - 1) << 16));
         break;
+    case NVME_ASYNCHRONOUS_EVENT_CONF:
+        n->features.async_config = dw11;
+        break;
     case NVME_TIMESTAMP:
         return nvme_set_feature_timestamp(n, cmd);
     default:
@@ -1085,6 +1203,25 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
     return NVME_SUCCESS;
 }
 
+static uint16_t nvme_aer(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+{
+    trace_pci_nvme_aer(nvme_cid(req));
+
+    if (n->outstanding_aers > n->params.aerl) {
+        trace_pci_nvme_aer_aerl_exceeded();
+        return NVME_AER_LIMIT_EXCEEDED;
+    }
+
+    n->aer_reqs[n->outstanding_aers] = req;
+    n->outstanding_aers++;
+
+    if (!QTAILQ_EMPTY(&n->aer_queue)) {
+        nvme_process_aers(n);
+    }
+
+    return NVME_NO_COMPLETE;
+}
+
 static uint16_t nvme_admin_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 {
     trace_pci_nvme_admin_cmd(nvme_cid(req), nvme_sqid(req), cmd->opcode);
@@ -1108,6 +1245,8 @@ static uint16_t nvme_admin_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
         return nvme_set_feature(n, cmd, req);
     case NVME_ADM_CMD_GET_FEATURES:
         return nvme_get_feature(n, cmd, req);
+    case NVME_ADM_CMD_ASYNC_EV_REQ:
+        return nvme_aer(n, cmd, req);
     default:
         trace_pci_nvme_err_invalid_admin_opc(cmd->opcode);
         return NVME_INVALID_OPCODE | NVME_DNR;
@@ -1162,6 +1301,15 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
         }
     }
 
+    while (!QTAILQ_EMPTY(&n->aer_queue)) {
+        NvmeAsyncEvent *event = QTAILQ_FIRST(&n->aer_queue);
+        QTAILQ_REMOVE(&n->aer_queue, event, entry);
+        g_free(event);
+    }
+
+    n->aer_queued = 0;
+    n->outstanding_aers = 0;
+
     blk_flush(n->conf.blk);
     n->bar.cc = 0;
 }
@@ -1258,6 +1406,8 @@ static int nvme_start_ctrl(NvmeCtrl *n)
 
     nvme_set_timestamp(n, 0ULL);
 
+    QTAILQ_INIT(&n->aer_queue);
+
     return 0;
 }
 
@@ -1479,6 +1629,26 @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
                            "completion queue doorbell write"
                            " for nonexistent queue,"
                            " sqid=%"PRIu32", ignoring", qid);
+
+            /*
+             * NVM Express v1.3d, Section 4.1 state: "If host software writes
+             * an invalid value to the Submission Queue Tail Doorbell or
+             * Completion Queue Head Doorbell regiter and an Asynchronous Event
+             * Request command is outstanding, then an asynchronous event is
+             * posted to the Admin Completion Queue with a status code of
+             * Invalid Doorbell Write Value."
+             *
+             * Also note that the spec includes the "Invalid Doorbell Register"
+             * status code, but nowhere does it specify when to use it.
+             * However, it seems reasonable to use it here in a similar
+             * fashion.
+             */
+            if (n->outstanding_aers) {
+                nvme_enqueue_event(n, NVME_AER_TYPE_ERROR,
+                                   NVME_AER_INFO_ERR_INVALID_DB_REGISTER,
+                                   NVME_LOG_ERROR_INFO);
+            }
+
             return;
         }
 
@@ -1489,6 +1659,13 @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
                            " beyond queue size, sqid=%"PRIu32","
                            " new_head=%"PRIu16", ignoring",
                            qid, new_head);
+
+            if (n->outstanding_aers) {
+                nvme_enqueue_event(n, NVME_AER_TYPE_ERROR,
+                                   NVME_AER_INFO_ERR_INVALID_DB_VALUE,
+                                   NVME_LOG_ERROR_INFO);
+            }
+
             return;
         }
 
@@ -1519,6 +1696,13 @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
                            "submission queue doorbell write"
                            " for nonexistent queue,"
                            " sqid=%"PRIu32", ignoring", qid);
+
+            if (n->outstanding_aers) {
+                nvme_enqueue_event(n, NVME_AER_TYPE_ERROR,
+                                   NVME_AER_INFO_ERR_INVALID_DB_REGISTER,
+                                   NVME_LOG_ERROR_INFO);
+            }
+
             return;
         }
 
@@ -1529,6 +1713,13 @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
                            " beyond queue size, sqid=%"PRIu32","
                            " new_tail=%"PRIu16", ignoring",
                            qid, new_tail);
+
+            if (n->outstanding_aers) {
+                nvme_enqueue_event(n, NVME_AER_TYPE_ERROR,
+                                   NVME_AER_INFO_ERR_INVALID_DB_VALUE,
+                                   NVME_LOG_ERROR_INFO);
+            }
+
             return;
         }
 
@@ -1649,6 +1840,7 @@ static void nvme_init_state(NvmeCtrl *n)
     n->temperature = NVME_TEMPERATURE;
     n->features.temp_thresh_hi = NVME_TEMPERATURE_WARNING;
     n->starttime_ms = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
+    n->aer_reqs = g_new0(NvmeRequest *, n->params.aerl + 1);
 }
 
 static void nvme_init_blk(NvmeCtrl *n, Error **errp)
@@ -1804,6 +1996,7 @@ static void nvme_init_ctrl(NvmeCtrl *n, PCIDevice *pci_dev)
      * inconsequential.
      */
     id->acl = 3;
+    id->aerl = n->params.aerl;
     id->frmw = (NVME_NUM_FW_SLOTS << 1) | NVME_FRMW_SLOT1_RO;
     id->lpa = NVME_LPA_EXTENDED;
 
@@ -1878,6 +2071,7 @@ static void nvme_exit(PCIDevice *pci_dev)
     g_free(n->namespaces);
     g_free(n->cq);
     g_free(n->sq);
+    g_free(n->aer_reqs);
 
     if (n->params.cmb_size_mb) {
         g_free(n->cmbuf);
@@ -1898,6 +2092,8 @@ static Property nvme_props[] = {
     DEFINE_PROP_UINT32("num_queues", NvmeCtrl, params.num_queues, 0),
     DEFINE_PROP_UINT32("max_ioqpairs", NvmeCtrl, params.max_ioqpairs, 64),
     DEFINE_PROP_UINT16("msix_qsize", NvmeCtrl, params.msix_qsize, 65),
+    DEFINE_PROP_UINT8("aerl", NvmeCtrl, params.aerl, 3),
+    DEFINE_PROP_UINT32("aer_max_queued", NvmeCtrl, params.aer_max_queued, 64),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index 8228978..1837233 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -9,10 +9,12 @@ typedef struct NvmeParams {
     uint32_t max_ioqpairs;
     uint16_t msix_qsize;
     uint32_t cmb_size_mb;
+    uint8_t  aerl;
+    uint32_t aer_max_queued;
 } NvmeParams;
 
 typedef struct NvmeAsyncEvent {
-    QSIMPLEQ_ENTRY(NvmeAsyncEvent) entry;
+    QTAILQ_ENTRY(NvmeAsyncEvent) entry;
     NvmeAerResult result;
 } NvmeAsyncEvent;
 
@@ -94,6 +96,7 @@ typedef struct NvmeCtrl {
     uint32_t    num_namespaces;
     uint32_t    max_q_ents;
     uint64_t    ns_size;
+    uint8_t     outstanding_aers;
     uint8_t     *cmbuf;
     uint32_t    irq_status;
     uint64_t    host_timestamp;                 /* Timestamp sent by the host */
@@ -103,6 +106,11 @@ typedef struct NvmeCtrl {
 
     HostMemoryBackend *pmrdev;
 
+    uint8_t     aer_mask;
+    NvmeRequest **aer_reqs;
+    QTAILQ_HEAD(, NvmeAsyncEvent) aer_queue;
+    int         aer_queued;
+
     NvmeNamespace   *namespaces;
     NvmeSQueue      **sq;
     NvmeCQueue      **cq;
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 3330d74..091af16 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -51,6 +51,15 @@ pci_nvme_getfeat_numq(int result) "get feature number of queues, result=%d"
 pci_nvme_setfeat_numq(int reqcq, int reqsq, int gotcq, int gotsq) "requested cq_count=%d sq_count=%d, responding with cq_count=%d sq_count=%d"
 pci_nvme_setfeat_timestamp(uint64_t ts) "set feature timestamp = 0x%"PRIx64""
 pci_nvme_getfeat_timestamp(uint64_t ts) "get feature timestamp = 0x%"PRIx64""
+pci_nvme_process_aers(int queued) "queued %d"
+pci_nvme_aer(uint16_t cid) "cid %"PRIu16""
+pci_nvme_aer_aerl_exceeded(void) "aerl exceeded"
+pci_nvme_aer_masked(uint8_t type, uint8_t mask) "type 0x%"PRIx8" mask 0x%"PRIx8""
+pci_nvme_aer_post_cqe(uint8_t typ, uint8_t info, uint8_t log_page) "type 0x%"PRIx8" info 0x%"PRIx8" lid 0x%"PRIx8""
+pci_nvme_enqueue_event(uint8_t typ, uint8_t info, uint8_t log_page) "type 0x%"PRIx8" info 0x%"PRIx8" lid 0x%"PRIx8""
+pci_nvme_enqueue_event_noqueue(int queued) "queued %d"
+pci_nvme_enqueue_event_masked(uint8_t typ) "type 0x%"PRIx8""
+pci_nvme_no_outstanding_aers(void) "ignoring event; no outstanding AERs"
 pci_nvme_enqueue_req_completion(uint16_t cid, uint16_t cqid, uint16_t status) "cid %"PRIu16" cqid %"PRIu16" status 0x%"PRIx16""
 pci_nvme_mmio_read(uint64_t addr) "addr 0x%"PRIx64""
 pci_nvme_mmio_write(uint64_t addr, uint64_t data) "addr 0x%"PRIx64" data 0x%"PRIx64""