LFENCE and SFENCE were introduced with the original SSE instruction set;
marking them incorrectly as cpuid(SSE2) causes failures for CPU models
that lack SSE2, for example pentium3.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/tcg/decode-new.c.inc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/i386/tcg/decode-new.c.inc b/target/i386/tcg/decode-new.c.inc
index 1f193716468..48bf730cd3e 100644
--- a/target/i386/tcg/decode-new.c.inc
+++ b/target/i386/tcg/decode-new.c.inc
@@ -345,9 +345,9 @@ static void decode_group15(DisasContext *s, CPUX86State *env, X86OpEntry *entry,
         [1] = X86_OP_ENTRYw(RDxxBASE,   R,y, cpuid(FSGSBASE) chk(o64) p_f3),
         [2] = X86_OP_ENTRYr(WRxxBASE,   R,y, cpuid(FSGSBASE) chk(o64) p_f3 zextT0),
         [3] = X86_OP_ENTRYr(WRxxBASE,   R,y, cpuid(FSGSBASE) chk(o64) p_f3 zextT0),
-        [5] = X86_OP_ENTRY0(LFENCE,          cpuid(SSE2) p_00),
+        [5] = X86_OP_ENTRY0(LFENCE,          cpuid(SSE) p_00),
         [6] = X86_OP_ENTRY0(MFENCE,          cpuid(SSE2) p_00),
-        [7] = X86_OP_ENTRY0(SFENCE,          cpuid(SSE2) p_00),
+        [7] = X86_OP_ENTRY0(SFENCE,          cpuid(SSE) p_00),
     };
 
     static const X86OpEntry group15_mem[8] = {
-- 
2.46.2

On 10/21/24 22:59, Paolo Bonzini wrote:
> LFENCE and SFENCE were introduced with the original SSE instruction set;
> marking them incorrectly as cpuid(SSE2) causes failures for CPU models
> that lack SSE2, for example pentium3.
> 
> Reported-by: Guenter Roeck<linux@roeck-us.net>
> Tested-by: Guenter Roeck<linux@roeck-us.net>
> Cc:qemu-stable@nongnu.org
> Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>
> ---
>   target/i386/tcg/decode-new.c.inc | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

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

r~