diff --git a/target/i386/tcg/misc_helper.c b/target/i386/tcg/misc_helper.c index 90b87fdef0..a25428c36e 100644 --- a/target/i386/tcg/misc_helper.c +++ b/target/i386/tcg/misc_helper.c @@ -167,6 +167,10 @@ void helper_write_crN(CPUX86State *env, int reg, target_ulong t0) cpu_x86_update_cr3(env, t0); break; case 4: + if (((t0 ^ env->cr[4]) & CR4_LA57_MASK) && + (env->hflags & HF_CS64_MASK)) { + raise_exception_ra(env, EXCP0D_GPF, GETPC()); + } cpu_x86_update_cr4(env, t0); break; case 8: