[PATCH 19/26] hw/intc/arm_gicv3_its: Don't use data if reading command failed

[Peter Maydell]

In process_cmdq(), we read 64 bits of the command packet, which
contain the command identifier, which we then switch() on to dispatch
to an appropriate sub-function.  However, if address_space_ldq_le()
reports a memory transaction failure, we still read the command
identifier out of the data and switch() on it.  Restructure the code
so that we stop immediately (stalling the command queue) in this
case.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/intc/arm_gicv3_its.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
index 32cf18c10af..f3eba92946d 100644
--- a/hw/intc/arm_gicv3_its.c
+++ b/hw/intc/arm_gicv3_its.c
@@ -670,8 +670,13 @@ static void process_cmdq(GICv3ITSState *s)
         data = address_space_ldq_le(as, s->cq.base_addr + cq_offset,
                                     MEMTXATTRS_UNSPECIFIED, &res);
         if (res != MEMTX_OK) {
-            result = false;
+            s->creadr = FIELD_DP64(s->creadr, GITS_CREADR, STALLED, 1);
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: could not read command at 0x%" PRIx64 "\n",
+                          __func__, s->cq.base_addr + cq_offset);
+            break;
         }
+
         cmd = (data & CMD_MASK);
 
         switch (cmd) {
-- 
2.25.1