hw/cxl: fix DC extent capacity tracking

Per cxl r3.2 Section 9.13.3.3, extent capacity tracking should include
extents in different states including added, pending, etc.

Before the change, for the in-device extent number tracking purpose, we only
have "total_extent_count" defined, which only tracks the number of
extents accepted. However, we need to track number of extents in other
states also, for now it is extents pending-to-add.

To fix that, we introduce a new counter for dynamic capacity
"nr_extents_accepted" which explicitly tracks number of the extents
accepted by the hosts, and fix "total_extent_count" to include
both accepted and pending extents counting.

Signed-off-by: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20250714174509.1984430-2-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 18 insertions, 8 deletions

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 299f232f26..0b615ea37a 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -2750,7 +2750,7 @@ static CXLRetCode cmd_dcd_get_dyn_cap_ext_list(const struct cxl_cmd *cmd,
     uint16_t out_pl_len, size;
     CXLDCExtent *ent;
 
-    if (start_extent_id > ct3d->dc.total_extent_count) {
+    if (start_extent_id > ct3d->dc.nr_extents_accepted) {
         return CXL_MBOX_INVALID_INPUT;
     }
 
@@ -2761,7 +2761,7 @@ static CXLRetCode cmd_dcd_get_dyn_cap_ext_list(const struct cxl_cmd *cmd,
     out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
 
     stl_le_p(&out->count, record_count);
-    stl_le_p(&out->total_extents, ct3d->dc.total_extent_count);
+    stl_le_p(&out->total_extents, ct3d->dc.nr_extents_accepted);
     stl_le_p(&out->generation_num, ct3d->dc.ext_list_gen_seq);
 
     if (record_count > 0) {
@@ -2883,16 +2883,20 @@ void cxl_extent_group_list_insert_tail(CXLDCExtentGroupList *list,
     QTAILQ_INSERT_TAIL(list, group, node);
 }
 
-void cxl_extent_group_list_delete_front(CXLDCExtentGroupList *list)
+uint32_t cxl_extent_group_list_delete_front(CXLDCExtentGroupList *list)
 {
     CXLDCExtent *ent, *ent_next;
     CXLDCExtentGroup *group = QTAILQ_FIRST(list);
+    uint32_t extents_deleted = 0;
 
     QTAILQ_REMOVE(list, group, node);
     QTAILQ_FOREACH_SAFE(ent, &group->list, node, ent_next) {
         cxl_remove_extent_from_extent_list(&group->list, ent);
+        extents_deleted++;
     }
     g_free(group);
+
+    return extents_deleted;
 }
 
 /*
@@ -3011,7 +3015,7 @@ static CXLRetCode cmd_dcd_add_dyn_cap_rsp(const struct cxl_cmd *cmd,
     CXLUpdateDCExtentListInPl *in = (void *)payload_in;
     CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
     CXLDCExtentList *extent_list = &ct3d->dc.extents;
-    uint32_t i;
+    uint32_t i, num;
     uint64_t dpa, len;
     CXLRetCode ret;
 
@@ -3020,7 +3024,8 @@ static CXLRetCode cmd_dcd_add_dyn_cap_rsp(const struct cxl_cmd *cmd,
     }
 
     if (in->num_entries_updated == 0) {
-        cxl_extent_group_list_delete_front(&ct3d->dc.extents_pending);
+        num = cxl_extent_group_list_delete_front(&ct3d->dc.extents_pending);
+        ct3d->dc.total_extent_count -= num;
         return CXL_MBOX_SUCCESS;
     }
 
@@ -3051,10 +3056,12 @@ static CXLRetCode cmd_dcd_add_dyn_cap_rsp(const struct cxl_cmd *cmd,
 
         cxl_insert_extent_to_extent_list(extent_list, dpa, len, NULL, 0);
         ct3d->dc.total_extent_count += 1;
+        ct3d->dc.nr_extents_accepted += 1;
         ct3_set_region_block_backed(ct3d, dpa, len);
     }
     /* Remove the first extent group in the pending list */
-    cxl_extent_group_list_delete_front(&ct3d->dc.extents_pending);
+    num = cxl_extent_group_list_delete_front(&ct3d->dc.extents_pending);
+    ct3d->dc.total_extent_count -= num;
 
     return CXL_MBOX_SUCCESS;
 }
@@ -3160,7 +3167,7 @@ free_and_exit:
         }
         *updated_list_size = 0;
     } else {
-        *updated_list_size = ct3d->dc.total_extent_count + cnt_delta;
+        *updated_list_size = ct3d->dc.nr_extents_accepted + cnt_delta;
     }
 
     return ret;
@@ -3222,7 +3229,10 @@ static CXLRetCode cmd_dcd_release_dyn_cap(const struct cxl_cmd *cmd,
         ct3_set_region_block_backed(ct3d, ent->start_dpa, ent->len);
         cxl_remove_extent_from_extent_list(&updated_list, ent);
     }
-    ct3d->dc.total_extent_count = updated_list_size;
+    ct3d->dc.total_extent_count += (updated_list_size -
+                                    ct3d->dc.nr_extents_accepted);
+
+    ct3d->dc.nr_extents_accepted = updated_list_size;
 
     return CXL_MBOX_SUCCESS;
 }