hw/cxl: Add clear poison mailbox command support.

Current implementation is very simple so many of the corner
cases do not exist (e.g. fragmenting larger poison list entries)

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230526170010.574-5-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 6c476ad7f4..e3401b6be8 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -65,6 +65,7 @@ enum {
     MEDIA_AND_POISON = 0x43,
         #define GET_POISON_LIST        0x0
         #define INJECT_POISON          0x1
+        #define CLEAR_POISON           0x2
 };
 
 /* 8.2.8.4.5.1 Command Return Codes */
@@ -512,6 +513,85 @@ static CXLRetCode cmd_media_inject_poison(struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+static CXLRetCode cmd_media_clear_poison(struct cxl_cmd *cmd,
+                                         CXLDeviceState *cxl_dstate,
+                                         uint16_t *len_unused)
+{
+    CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev, cxl_dstate);
+    CXLPoisonList *poison_list = &ct3d->poison_list;
+    CXLType3Class *cvc = CXL_TYPE3_GET_CLASS(ct3d);
+    struct clear_poison_pl {
+        uint64_t dpa;
+        uint8_t data[64];
+    };
+    CXLPoison *ent;
+    uint64_t dpa;
+
+    struct clear_poison_pl *in = (void *)cmd->payload;
+
+    dpa = ldq_le_p(&in->dpa);
+    if (dpa + CXL_CACHE_LINE_SIZE > cxl_dstate->mem_size) {
+        return CXL_MBOX_INVALID_PA;
+    }
+
+    /* Clearing a region with no poison is not an error so always do so */
+    if (cvc->set_cacheline) {
+        if (!cvc->set_cacheline(ct3d, dpa, in->data)) {
+            return CXL_MBOX_INTERNAL_ERROR;
+        }
+    }
+
+    QLIST_FOREACH(ent, poison_list, node) {
+        /*
+         * Test for contained in entry. Simpler than general case
+         * as clearing 64 bytes and entries 64 byte aligned
+         */
+        if ((dpa >= ent->start) && (dpa < ent->start + ent->length)) {
+            break;
+        }
+    }
+    if (!ent) {
+        return CXL_MBOX_SUCCESS;
+    }
+
+    QLIST_REMOVE(ent, node);
+    ct3d->poison_list_cnt--;
+
+    if (dpa > ent->start) {
+        CXLPoison *frag;
+        /* Cannot overflow as replacing existing entry */
+
+        frag = g_new0(CXLPoison, 1);
+
+        frag->start = ent->start;
+        frag->length = dpa - ent->start;
+        frag->type = ent->type;
+
+        QLIST_INSERT_HEAD(poison_list, frag, node);
+        ct3d->poison_list_cnt++;
+    }
+
+    if (dpa + CXL_CACHE_LINE_SIZE < ent->start + ent->length) {
+        CXLPoison *frag;
+
+        if (ct3d->poison_list_cnt == CXL_POISON_LIST_LIMIT) {
+            cxl_set_poison_list_overflowed(ct3d);
+        } else {
+            frag = g_new0(CXLPoison, 1);
+
+            frag->start = dpa + CXL_CACHE_LINE_SIZE;
+            frag->length = ent->start + ent->length - frag->start;
+            frag->type = ent->type;
+            QLIST_INSERT_HEAD(poison_list, frag, node);
+            ct3d->poison_list_cnt++;
+        }
+    }
+    /* Any fragments have been added, free original entry */
+    g_free(ent);
+
+    return CXL_MBOX_SUCCESS;
+}
+
 #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
 #define IMMEDIATE_DATA_CHANGE (1 << 2)
 #define IMMEDIATE_POLICY_CHANGE (1 << 3)
@@ -543,6 +623,8 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
         cmd_media_get_poison_list, 16, 0 },
     [MEDIA_AND_POISON][INJECT_POISON] = { "MEDIA_AND_POISON_INJECT_POISON",
         cmd_media_inject_poison, 8, 0 },
+    [MEDIA_AND_POISON][CLEAR_POISON] = { "MEDIA_AND_POISON_CLEAR_POISON",
+        cmd_media_clear_poison, 72, 0 },
 };
 
 void cxl_process_mailbox(CXLDeviceState *cxl_dstate)