[Qemu-devel] [PATCH] sparc: fix leon3 casa instruction when MMU is disabled

[KONRAD Frederic]

From: KONRAD Frederic <address@hidden>

Since the commit af7a06bac7d3abb2da48ef3277d2a415772d2ae8:
`casa [..](10), .., ..` (and probably others alternate space instructions)
triggers a data access exception when the MMU is disabled.

When we enter get_asi(...) dc->mem_idx is set to MMU_PHYS_IDX when the MMU
is disabled. Just keep mem_idx unchanged in this case so we passthrough the
MMU when it is disabled.

Signed-off-by: KONRAD Frederic <address@hidden>
---

Notes:
    Changes RFC -> V1:
     * emit the instruction with MMU_PHYS_IDX instead of checking that the MMU
       is enabled in get_physical_address(..)

 target/sparc/translate.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/target/sparc/translate.c b/target/sparc/translate.c
index 71e0853..5aa367a 100644
--- a/target/sparc/translate.c
+++ b/target/sparc/translate.c
@@ -2093,6 +2093,11 @@ static DisasASI get_asi(DisasContext *dc, int insn, 
TCGMemOp memop)
             type = GET_ASI_BFILL;
             break;
         }
+
+        /* MMU_PHYS_IDX is used when the MMU is disabled to passthrough the
+         * permissions check in get_physical_address(..).
+         */
+        mem_idx = (dc->mem_idx == MMU_PHYS_IDX) ? MMU_PHYS_IDX : mem_idx;
     } else {
         gen_exception(dc, TT_PRIV_INSN);
         type = GET_ASI_EXCP;
-- 
1.8.3.1