target/arm: Make NV reads of CurrentEL return EL2

FEAT_NV requires that when HCR_EL2.NV is set reads of the CurrentEL
register from EL1 always report EL2 rather than the real EL.
Implement this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Miguel Luis <miguel.luis@oracle.com>

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index f5377dbaf2d2c6c7a343ab1accbdeb9f0625e91d..ed1cc019a4ce32fd908793946285fc49292e2001 100644 (file)
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -2241,12 +2241,17 @@ static void handle_sys(DisasContext *s, bool isread,
         }
         return;
     case ARM_CP_CURRENTEL:
-        /* Reads as current EL value from pstate, which is
+    {
+        /*
+         * Reads as current EL value from pstate, which is
          * guaranteed to be constant by the tb flags.
+         * For nested virt we should report EL2.
          */
+        int el = s->nv ? 2 : s->current_el;
         tcg_rt = cpu_reg(s, rt);
-        tcg_gen_movi_i64(tcg_rt, s->current_el << 2);
+        tcg_gen_movi_i64(tcg_rt, el << 2);
         return;
+    }
     case ARM_CP_DC_ZVA:
         /* Writes clear the aligned block of memory which rt points into. */
         if (s->mte_active[0]) {