Re: [Qemu-devel] [RFC v3 PATCH 14/14] target-i386: Generate fences for x86

[Richard Henderson]

On 06/17/2016 09:03 PM, Pranith Kumar wrote:

         case 0xe8 ... 0xef: /* lfence */
+            tcg_gen_mb(TCG_MO_LD_LD | TCG_BAR_SC);
+            break;
         case 0xf0 ... 0xf7: /* mfence */
             if (!(s->cpuid_features & CPUID_SSE2)
                 || (prefixes & PREFIX_LOCK)) {
                 goto illegal_op;
             }
+            tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);

You need to duplicate the sse2 check if you split lfence from mfence.


r~