tcg/loongarch64: Check the host supports unaligned accesses

This should be true of all loongarch64 running Linux.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/loongarch64/tcg-target.c.inc

@@ -30,6 +30,7 @@
  */
 
 #include "../tcg-ldst.c.inc"
+#include <asm/hwcap.h>
 
 #ifdef CONFIG_DEBUG_TCG
 static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {
@@ -1674,6 +1675,14 @@ static void tcg_target_qemu_prologue(TCGContext *s)
 
 static void tcg_target_init(TCGContext *s)
 {
+    unsigned long hwcap = qemu_getauxval(AT_HWCAP);
+
+    /* Server and desktop class cpus have UAL; embedded cpus do not. */
+    if (!(hwcap & HWCAP_LOONGARCH_UAL)) {
+        error_report("TCG: unaligned access support required; exiting");
+        exit(EXIT_FAILURE);
+    }
+
     tcg_target_available_regs[TCG_TYPE_I32] = ALL_GENERAL_REGS;
     tcg_target_available_regs[TCG_TYPE_I64] = ALL_GENERAL_REGS;