refactor(cpufeat): enable FEAT_NV2 for FEAT_STATE_CHECKED
At the moment we only support for FEAT_NV2 to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (CTX_INCLUDE_NEVE_REGS=2), by
splitting get_armv8_4_feat_nv_support() into an ID register reading
function and a second function to report the support status. That
function considers both build time settings and runtime information
(if needed), and is used before we access the VNCR_EL2 system register.
Also move the context saving code from assembly to C, and use the new
is_feat_nv2_supported() function to guard its execution.
Change the FVP platform default to the now supported dynamic option (=2),
so the right decision can be made by the code at runtime.
Change-Id: I85b080641995fb72cfd4ac933f7a3f75770c2cb9
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/common/feat_detect.c b/common/feat_detect.c
index b335a61..1c505e2 100644
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@@ -90,18 +90,6 @@
#endif
}
-/**************************************************************
- * Feature : FEAT_NV2 (Enhanced Nested Virtualization Support)
- *************************************************************/
-static void read_feat_nv2(void)
-{
-#if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_ALWAYS)
- unsigned int nv = get_armv8_4_feat_nv_support();
-
- feat_detect_panic((nv == ID_AA64MMFR2_EL1_NV2_SUPPORTED), "NV2");
-#endif
-}
-
/***********************************
* Feature : FEAT_SEL2 (Secure EL2)
**********************************/
@@ -223,7 +211,8 @@
"AMUv1", 1, 2);
check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(),
"MPAM", 1, 17);
- read_feat_nv2();
+ check_feature(CTX_INCLUDE_NEVE_REGS, read_feat_nv_id_field(),
+ "NV2", 2, 2);
read_feat_sel2();
check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(),
"TRF", 1, 1);