lib: el3_runtime: Conditionally save/restore EL2 NEVE registers
Include EL2 registers related to Nested Virtualization in EL2 context
save/restore routines if architecture supports it and platform wants to
use these features in Secure world.
Change-Id: If006ab83bbc2576488686f5ffdff88b91adced5c
Signed-off-by: Arunachalam Ganapathy <arunachalam.ganapathy@arm.com>
diff --git a/Makefile b/Makefile
index c5073e0..9614238 100644
--- a/Makefile
+++ b/Makefile
@@ -865,6 +865,7 @@
CTX_INCLUDE_PAUTH_REGS \
CTX_INCLUDE_MTE_REGS \
CTX_INCLUDE_EL2_REGS \
+ CTX_INCLUDE_NEVE_REGS \
DEBUG \
DYN_DISABLE_AUTH \
EL3_EXCEPTION_HANDLING \
@@ -953,6 +954,7 @@
EL3_EXCEPTION_HANDLING \
CTX_INCLUDE_MTE_REGS \
CTX_INCLUDE_EL2_REGS \
+ CTX_INCLUDE_NEVE_REGS \
DECRYPTION_SUPPORT_${DECRYPTION_SUPPORT} \
ENABLE_AMU \
ENABLE_ASSERTIONS \
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 40fc5db..8adf4ad 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -161,6 +161,10 @@
registers to be included when saving and restoring the CPU context. Default
is 0.
+- ``CTX_INCLUDE_NEVE_REGS``: Boolean option that, when set to 1, will cause the
+ Armv8.4-NV registers to be saved/restored when entering/exiting an EL2
+ execution context. Default value is 0.
+
- ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, enables
Pointer Authentication for Secure world. This will cause the ARMv8.3-PAuth
registers to be included when saving and restoring the CPU context as
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S
index 785e850..c942c10 100644
--- a/lib/el3_runtime/aarch64/context.S
+++ b/lib/el3_runtime/aarch64/context.S
@@ -200,8 +200,10 @@
mrs x12, vdisr_el2
str x12, [x0, #CTX_VDISR_EL2]
+#if CTX_INCLUDE_NEVE_REGS
mrs x13, vncr_el2
str x13, [x0, #CTX_VNCR_EL2]
+#endif
mrs x14, vsesr_el2
str x14, [x0, #CTX_VSESR_EL2]
@@ -395,8 +397,10 @@
ldr x13, [x0, #CTX_VDISR_EL2]
msr vdisr_el2, x13
+#if CTX_INCLUDE_NEVE_REGS
ldr x14, [x0, #CTX_VNCR_EL2]
msr vncr_el2, x14
+#endif
ldr x15, [x0, #CTX_VSESR_EL2]
msr vsesr_el2, x15
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index bc4982d..578bd59 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -62,6 +62,11 @@
# world. It is not needed to use it in the Non-secure world.
CTX_INCLUDE_PAUTH_REGS := 0
+# Include Nested virtualization control (Armv8.4-NV) registers in cpu context.
+# This must be set to 1 if architecture implements Nested Virtualization
+# Extension and platform wants to use this feature in the Secure world
+CTX_INCLUDE_NEVE_REGS := 0
+
# Debug build
DEBUG := 0