The Loongson-3A4000 is a GS464V-based processor with MIPS MSA ASE:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg763059.html

Commit af868995e1b correctly set the 'MSA present' bit of Config3
register, but forgot to allow the MSA instructions decoding in
insn_flags, so executing them triggers a 'Reserved Instruction'.

Fix by adding the ASE_MSA mask to insn_flags.

Fixes: af868995e1b ("target/mips: Add Loongson-3 CPU definition")
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
Buggy since 5.1, so probably not a big deal.
---
 target/mips/translate_init.c.inc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/mips/translate_init.c.inc b/target/mips/translate_init.c.inc
index ea85d5c6a79..79f75ed863c 100644
--- a/target/mips/translate_init.c.inc
+++ b/target/mips/translate_init.c.inc
@@ -832,7 +832,7 @@ const mips_def_t mips_defs[] =
         .mmu_type = MMU_TYPE_R4000,
     },
     {
-        .name = "Loongson-3A4000",
+        .name = "Loongson-3A4000", /* GS464V-based */
         .CP0_PRid = 0x14C000,
         /* 64KB I-cache and d-cache. 4 way with 32 bit cache line size.  */
         .CP0_Config0 = MIPS_CONFIG0 | (0x1 << CP0C0_AR) | (0x2 << CP0C0_AT) |
@@ -885,7 +885,7 @@ const mips_def_t mips_defs[] =
         .CP1_fcr31_rw_bitmask = 0xFF83FFFF,
         .SEGBITS = 48,
         .PABITS = 48,
-        .insn_flags = CPU_LOONGSON3A,
+        .insn_flags = CPU_LOONGSON3A | ASE_MSA,
         .mmu_type = MMU_TYPE_R4000,
     },
     {
-- 
2.26.2

On 11/30/20 4:22 AM, Philippe Mathieu-Daudé wrote:
> The Loongson-3A4000 is a GS464V-based processor with MIPS MSA ASE:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg763059.html
> 
> Commit af868995e1b correctly set the 'MSA present' bit of Config3
> register, but forgot to allow the MSA instructions decoding in
> insn_flags, so executing them triggers a 'Reserved Instruction'.
> 
> Fix by adding the ASE_MSA mask to insn_flags.
> 
> Fixes: af868995e1b ("target/mips: Add Loongson-3 CPU definition")
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> Buggy since 5.1, so probably not a big deal.
> ---
>  target/mips/translate_init.c.inc | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Reviewed-by: Huacai Chen <chenhc@lemote.com>

On Tue, Dec 1, 2020 at 2:24 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 11/30/20 4:22 AM, Philippe Mathieu-Daudé wrote:
> > The Loongson-3A4000 is a GS464V-based processor with MIPS MSA ASE:
> > https://www.mail-archive.com/qemu-devel@nongnu.org/msg763059.html
> >
> > Commit af868995e1b correctly set the 'MSA present' bit of Config3
> > register, but forgot to allow the MSA instructions decoding in
> > insn_flags, so executing them triggers a 'Reserved Instruction'.
> >
> > Fix by adding the ASE_MSA mask to insn_flags.
> >
> > Fixes: af868995e1b ("target/mips: Add Loongson-3 CPU definition")
> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > ---
> > Buggy since 5.1, so probably not a big deal.
> > ---
> >  target/mips/translate_init.c.inc | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
>
> r~
>


-- 
Huacai Chen

On 11/30/20 11:22 AM, Philippe Mathieu-Daudé wrote:
> The Loongson-3A4000 is a GS464V-based processor with MIPS MSA ASE:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg763059.html
> 
> Commit af868995e1b correctly set the 'MSA present' bit of Config3
> register, but forgot to allow the MSA instructions decoding in
> insn_flags, so executing them triggers a 'Reserved Instruction'.
> 
> Fix by adding the ASE_MSA mask to insn_flags.
> 
> Fixes: af868995e1b ("target/mips: Add Loongson-3 CPU definition")
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> Buggy since 5.1, so probably not a big deal.
> ---
>  target/mips/translate_init.c.inc | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Thanks, applied to mips-next.