[PATCH V4 7/8] hw/block/nvme: support changed namespace asyncrohous event

[Minwoo Im]

If namespace inventory is changed due to some reasons (e.g., namespace
attachment/detachment), controller can send out event notifier to the
host to manage namespaces.

This patch sends out the AEN to the host after either attach or detach
namespaces from controllers.  To support clear of the event from the
controller, this patch also implemented Get Log Page command for Changed
Namespace List log type.  To return namespace id list through the
command, when namespace inventory is updated, id is added to the
per-controller list (changed_ns_list).

To indicate the support of this async event, this patch set
OAES(Optional Asynchronous Events Supported) in Identify Controller data
structure.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
---
 hw/block/nvme-ns.h   |  1 +
 hw/block/nvme.c      | 57 ++++++++++++++++++++++++++++++++++++++++++++
 hw/block/nvme.h      |  4 ++++
 include/block/nvme.h |  7 ++++++
 4 files changed, 69 insertions(+)

diff --git a/hw/block/nvme-ns.h b/hw/block/nvme-ns.h
index b0c00e115d81..318d3aebe1a8 100644
--- a/hw/block/nvme-ns.h
+++ b/hw/block/nvme-ns.h
@@ -53,6 +53,7 @@ typedef struct NvmeNamespace {
     uint8_t      csi;
 
     NvmeSubsystem   *subsys;
+    QTAILQ_ENTRY(NvmeNamespace) entry;
 
     NvmeIdNsZoned   *id_ns_zoned;
     NvmeZone        *zone_array;
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 68c2e63d9412..7e6f91923fd7 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -2980,6 +2980,49 @@ static uint16_t nvme_error_info(NvmeCtrl *n, uint8_t 
rae, uint32_t buf_len,
                     DMA_DIRECTION_FROM_DEVICE, req);
 }
 
+static uint16_t nvme_changed_nslist(NvmeCtrl *n, uint8_t rae, uint32_t buf_len,
+                                    uint64_t off, NvmeRequest *req)
+{
+    uint32_t nslist[1024];
+    uint32_t trans_len;
+    int i = 0;
+    uint32_t nsid;
+
+    memset(nslist, 0x0, sizeof(nslist));
+    trans_len = MIN(sizeof(nslist) - off, buf_len);
+
+    while ((nsid = find_first_bit(n->changed_nsids, NVME_CHANGED_NSID_SIZE)) !=
+            NVME_CHANGED_NSID_SIZE) {
+        /*
+         * If more than 1024 namespaces, the first entry in the log page should
+         * be set to 0xffffffff and the others to 0 as spec.
+         */
+        if (i == ARRAY_SIZE(nslist)) {
+            memset(nslist, 0x0, sizeof(nslist));
+            nslist[0] = 0xffffffff;
+            break;
+        }
+
+        nslist[i++] = nsid;
+        clear_bit(nsid, n->changed_nsids);
+    }
+
+    /*
+     * Remove all the remaining list entries in case returns directly due to
+     * more than 1024 namespaces.
+     */
+    if (nslist[0] == 0xffffffff) {
+        bitmap_zero(n->changed_nsids, NVME_CHANGED_NSID_SIZE);
+    }
+
+    if (!rae) {
+        nvme_clear_events(n, NVME_AER_TYPE_NOTICE);
+    }
+
+    return nvme_dma(n, ((uint8_t *)nslist) + off, trans_len,
+                    DMA_DIRECTION_FROM_DEVICE, req);
+}
+
 static uint16_t nvme_cmd_effects(NvmeCtrl *n, uint8_t csi, uint32_t buf_len,
                                  uint64_t off, NvmeRequest *req)
 {
@@ -3064,6 +3107,8 @@ static uint16_t nvme_get_log(NvmeCtrl *n, NvmeRequest 
*req)
         return nvme_smart_info(n, rae, len, off, req);
     case NVME_LOG_FW_SLOT_INFO:
         return nvme_fw_log_info(n, len, off, req);
+    case NVME_LOG_CHANGED_NSLIST:
+        return nvme_changed_nslist(n, rae, len, off, req);
     case NVME_LOG_CMD_EFFECTS:
         return nvme_cmd_effects(n, csi, len, off, req);
     default:
@@ -3920,6 +3965,16 @@ static uint16_t nvme_ns_attachment(NvmeCtrl *n, 
NvmeRequest *req)
 
             nvme_ns_detach(ctrl, ns);
         }
+
+        /*
+         * Add namespace id to the changed namespace id list for event clearing
+         * via Get Log Page command.
+         */
+        if (!test_and_set_bit(nsid, ctrl->changed_nsids)) {
+            nvme_enqueue_event(ctrl, NVME_AER_TYPE_NOTICE,
+                               NVME_AER_INFO_NOTICE_NS_ATTR_CHANGED,
+                               NVME_LOG_CHANGED_NSLIST);
+        }
     }
 
     return NVME_SUCCESS;
@@ -4910,6 +4965,8 @@ static void nvme_init_ctrl(NvmeCtrl *n, PCIDevice 
*pci_dev)
 
     id->cntlid = cpu_to_le16(n->cntlid);
 
+    id->oaes = cpu_to_le32(NVME_OAES_NS_ATTR);
+
     id->rab = 6;
 
     if (n->params.use_intel_id) {
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index 74a00ab21a55..7245c2b638d9 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -177,6 +177,10 @@ typedef struct NvmeCtrl {
     QTAILQ_HEAD(, NvmeAsyncEvent) aer_queue;
     int         aer_queued;
 
+    /* Namespace ID is started with 1 so bitmap should be 1-based */
+#define NVME_CHANGED_NSID_SIZE  (NVME_MAX_NAMESPACES + 1)
+    DECLARE_BITMAP(changed_nsids, NVME_CHANGED_NSID_SIZE);
+
     NvmeSubsystem   *subsys;
 
     NvmeNamespace   namespace;
diff --git a/include/block/nvme.h b/include/block/nvme.h
index 339784d9c23a..eb0b31e949c2 100644
--- a/include/block/nvme.h
+++ b/include/block/nvme.h
@@ -760,6 +760,7 @@ typedef struct QEMU_PACKED NvmeCopySourceRange {
 enum NvmeAsyncEventRequest {
     NVME_AER_TYPE_ERROR                     = 0,
     NVME_AER_TYPE_SMART                     = 1,
+    NVME_AER_TYPE_NOTICE                    = 2,
     NVME_AER_TYPE_IO_SPECIFIC               = 6,
     NVME_AER_TYPE_VENDOR_SPECIFIC           = 7,
     NVME_AER_INFO_ERR_INVALID_DB_REGISTER   = 0,
@@ -771,6 +772,7 @@ enum NvmeAsyncEventRequest {
     NVME_AER_INFO_SMART_RELIABILITY         = 0,
     NVME_AER_INFO_SMART_TEMP_THRESH         = 1,
     NVME_AER_INFO_SMART_SPARE_THRESH        = 2,
+    NVME_AER_INFO_NOTICE_NS_ATTR_CHANGED    = 0,
 };
 
 typedef struct QEMU_PACKED NvmeAerResult {
@@ -940,6 +942,7 @@ enum NvmeLogIdentifier {
     NVME_LOG_ERROR_INFO     = 0x01,
     NVME_LOG_SMART_INFO     = 0x02,
     NVME_LOG_FW_SLOT_INFO   = 0x03,
+    NVME_LOG_CHANGED_NSLIST = 0x04,
     NVME_LOG_CMD_EFFECTS    = 0x05,
 };
 
@@ -1046,6 +1049,10 @@ typedef struct NvmeIdCtrlZoned {
     uint8_t     rsvd1[4095];
 } NvmeIdCtrlZoned;
 
+enum NvmeIdCtrlOaes {
+    NVME_OAES_NS_ATTR   = 1 << 8,
+};
+
 enum NvmeIdCtrlOacs {
     NVME_OACS_SECURITY  = 1 << 0,
     NVME_OACS_FORMAT    = 1 << 1,
-- 
2.27.0