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-rw-r--r--hw/intc/arm_gicv3_its.c59
1 files changed, 38 insertions, 21 deletions
diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
index c1f76682d0..10901a5e70 100644
--- a/hw/intc/arm_gicv3_its.c
+++ b/hw/intc/arm_gicv3_its.c
@@ -45,6 +45,23 @@ typedef struct {
     uint64_t itel;
 } IteEntry;
 
+/*
+ * The ITS spec permits a range of CONSTRAINED UNPREDICTABLE options
+ * if a command parameter is not correct. These include both "stall
+ * processing of the command queue" and "ignore this command, and
+ * keep processing the queue". In our implementation we choose that
+ * memory transaction errors reading the command packet provoke a
+ * stall, but errors in parameters cause us to ignore the command
+ * and continue processing.
+ * The process_* functions which handle individual ITS commands all
+ * return an ItsCmdResult which tells process_cmdq() whether it should
+ * stall or keep going.
+ */
+typedef enum ItsCmdResult {
+    CMD_STALL = 0,
+    CMD_CONTINUE = 1,
+} ItsCmdResult;
+
 static uint64_t baser_base_addr(uint64_t value, uint32_t page_sz)
 {
     uint64_t result = 0;
@@ -217,8 +234,8 @@ static uint64_t get_dte(GICv3ITSState *s, uint32_t devid, MemTxResult *res)
  * 3. handling of ITS CLEAR command
  * 4. handling of ITS DISCARD command
  */
-static bool process_its_cmd(GICv3ITSState *s, uint64_t value, uint32_t offset,
-                            ItsCmdType cmd)
+static ItsCmdResult process_its_cmd(GICv3ITSState *s, uint64_t value,
+                                    uint32_t offset, ItsCmdType cmd)
 {
     AddressSpace *as = &s->gicv3->dma_as;
     uint32_t devid, eventid;
@@ -231,7 +248,7 @@ static bool process_its_cmd(GICv3ITSState *s, uint64_t value, uint32_t offset,
     bool ite_valid = false;
     uint64_t cte = 0;
     bool cte_valid = false;
-    bool result = false;
+    ItsCmdResult result = CMD_STALL;
     uint64_t rdbase;
 
     if (cmd == NONE) {
@@ -324,15 +341,15 @@ static bool process_its_cmd(GICv3ITSState *s, uint64_t value, uint32_t offset,
         if (cmd == DISCARD) {
             IteEntry ite = {};
             /* remove mapping from interrupt translation table */
-            result = update_ite(s, eventid, dte, ite);
+            result = update_ite(s, eventid, dte, ite) ? CMD_CONTINUE : CMD_STALL;
         }
     }
 
     return result;
 }
 
-static bool process_mapti(GICv3ITSState *s, uint64_t value, uint32_t offset,
-                          bool ignore_pInt)
+static ItsCmdResult process_mapti(GICv3ITSState *s, uint64_t value,
+                                  uint32_t offset, bool ignore_pInt)
 {
     AddressSpace *as = &s->gicv3->dma_as;
     uint32_t devid, eventid;
@@ -343,7 +360,7 @@ static bool process_mapti(GICv3ITSState *s, uint64_t value, uint32_t offset,
     MemTxResult res = MEMTX_OK;
     uint16_t icid = 0;
     uint64_t dte = 0;
-    bool result = false;
+    ItsCmdResult result = CMD_STALL;
 
     devid = ((value & DEVID_MASK) >> DEVID_SHIFT);
     offset += NUM_BYTES_IN_DW;
@@ -404,7 +421,7 @@ static bool process_mapti(GICv3ITSState *s, uint64_t value, uint32_t offset,
         ite.itel = FIELD_DP64(ite.itel, ITE_L, DOORBELL, INTID_SPURIOUS);
         ite.iteh = FIELD_DP32(ite.iteh, ITE_H, ICID, icid);
 
-        result = update_ite(s, eventid, dte, ite);
+        result = update_ite(s, eventid, dte, ite) ? CMD_CONTINUE : CMD_STALL;
     }
 
     return result;
@@ -472,14 +489,14 @@ static bool update_cte(GICv3ITSState *s, uint16_t icid, bool valid,
     }
 }
 
-static bool process_mapc(GICv3ITSState *s, uint32_t offset)
+static ItsCmdResult process_mapc(GICv3ITSState *s, uint32_t offset)
 {
     AddressSpace *as = &s->gicv3->dma_as;
     uint16_t icid;
     uint64_t rdbase;
     bool valid;
     MemTxResult res = MEMTX_OK;
-    bool result = false;
+    ItsCmdResult result = CMD_STALL;
     uint64_t value;
 
     offset += NUM_BYTES_IN_DW;
@@ -509,7 +526,7 @@ static bool process_mapc(GICv3ITSState *s, uint32_t offset)
          * command in the queue
          */
     } else {
-        result = update_cte(s, icid, valid, rdbase);
+        result = update_cte(s, icid, valid, rdbase) ? CMD_CONTINUE : CMD_STALL;
     }
 
     return result;
@@ -578,7 +595,8 @@ static bool update_dte(GICv3ITSState *s, uint32_t devid, bool valid,
     }
 }
 
-static bool process_mapd(GICv3ITSState *s, uint64_t value, uint32_t offset)
+static ItsCmdResult process_mapd(GICv3ITSState *s, uint64_t value,
+                                 uint32_t offset)
 {
     AddressSpace *as = &s->gicv3->dma_as;
     uint32_t devid;
@@ -586,7 +604,7 @@ static bool process_mapd(GICv3ITSState *s, uint64_t value, uint32_t offset)
     uint64_t itt_addr;
     bool valid;
     MemTxResult res = MEMTX_OK;
-    bool result = false;
+    ItsCmdResult result = CMD_STALL;
 
     devid = ((value & DEVID_MASK) >> DEVID_SHIFT);
 
@@ -623,7 +641,7 @@ static bool process_mapd(GICv3ITSState *s, uint64_t value, uint32_t offset)
          * command in the queue
          */
     } else {
-        result = update_dte(s, devid, valid, size, itt_addr);
+        result = update_dte(s, devid, valid, size, itt_addr) ? CMD_CONTINUE : CMD_STALL;
     }
 
     return result;
@@ -641,7 +659,6 @@ static void process_cmdq(GICv3ITSState *s)
     uint64_t data;
     AddressSpace *as = &s->gicv3->dma_as;
     MemTxResult res = MEMTX_OK;
-    bool result = true;
     uint8_t cmd;
     int i;
 
@@ -668,6 +685,8 @@ static void process_cmdq(GICv3ITSState *s)
     }
 
     while (wr_offset != rd_offset) {
+        ItsCmdResult result = CMD_CONTINUE;
+
         cq_offset = (rd_offset * GITS_CMDQ_ENTRY_SIZE);
         data = address_space_ldq_le(as, s->cq.base_addr + cq_offset,
                                     MEMTXATTRS_UNSPECIFIED, &res);
@@ -726,18 +745,16 @@ static void process_cmdq(GICv3ITSState *s)
         default:
             break;
         }
-        if (result) {
+        if (result == CMD_CONTINUE) {
             rd_offset++;
             rd_offset %= s->cq.num_entries;
             s->creadr = FIELD_DP64(s->creadr, GITS_CREADR, OFFSET, rd_offset);
         } else {
-            /*
-             * in this implementation, in case of dma read/write error
-             * we stall the command processing
-             */
+            /* CMD_STALL */
             s->creadr = FIELD_DP64(s->creadr, GITS_CREADR, STALLED, 1);
             qemu_log_mask(LOG_GUEST_ERROR,
-                          "%s: %x cmd processing failed\n", __func__, cmd);
+                          "%s: 0x%x cmd processing failed, stalling\n",
+                          __func__, cmd);
             break;
         }
     }