Hi Peter,

On 14/7/23 19:26, Peter Maydell wrote:
In CPUSparcState we define the fprs field as uint64_t.  However we
then refer to it in translate.c via a TCGv_i32 which we set up with
tcg_global_mem_new_ptr().  This means that on a big-endian host when
the guest does something to writo te the FPRS register this value
ends up in the wrong half of the uint64_t, and the QEMU C code that
refers to env->fprs sees the wrong value.  The effect of this is that
guest code that enables the FPU crashes with spurious FPU Disabled
exceptions.  In particular, this is why
  tests/avocado/machine_sparc64_sun4u.py:Sun4uMachine.test_sparc64_sun4u
times out on an s390 host.

There are multiple ways we could fix this; since there are actually
only three bits in the FPRS register and the code in translate.c
would be a bit painful to convert to dealing with a TCGv_i64, change
the type of the CPU state struct field to match what translate.c is
expecting.

(None of the other fields referenced by the r32[] array in
sparc_tcg_init() have the wrong type.)

Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
Another in my occasional series of "fix an avocado failure on
s390" Friday afternoon patches :-)

:)

diff --git a/target/sparc/gdbstub.c b/target/sparc/gdbstub.c
index a1c8fdc4d55..bddb9609b7b 100644
--- a/target/sparc/gdbstub.c
+++ b/target/sparc/gdbstub.c
@@ -96,7 +96,10 @@ int sparc_cpu_gdb_read_register(CPUState *cs, GByteArray 
*mem_buf, int n)
      case 83:
          return gdb_get_regl(mem_buf, env->fsr);
      case 84:
-        return gdb_get_regl(mem_buf, env->fprs);
+    {
+        target_ulong fprs = env->fprs;
+        return gdb_get_regl(mem_buf, fprs);

Why not return gdb_get_reg32() ?

+    }


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