[PATCH v5 03/23] xen/riscv: introduce nospec.h

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

>From the unpriviliged doc:
  No standard hints are presently defined.
  We anticipate standard hints to eventually include memory-system spatial
  and temporal locality hints, branch prediction hints, thread-scheduling
  hints, security tags, and instrumentation flags for simulation/emulation.

Also, there are no speculation execution barriers.

Therefore, functions evaluate_nospec() and block_speculation() should
remain empty until a specific platform has an extension to deal with
speculation execution.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
 Changes in V5:
   - new patch
---
 xen/arch/riscv/include/asm/nospec.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 xen/arch/riscv/include/asm/nospec.h

diff --git a/xen/arch/riscv/include/asm/nospec.h 
b/xen/arch/riscv/include/asm/nospec.h
new file mode 100644
index 0000000000..4fb404a0a2
--- /dev/null
+++ b/xen/arch/riscv/include/asm/nospec.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2024 Vates */
+
+#ifndef _ASM_GENERIC_NOSPEC_H
+#define _ASM_GENERIC_NOSPEC_H
+
+static inline bool evaluate_nospec(bool condition)
+{
+    return condition;
+}
+
+static inline void block_speculation(void)
+{
+}
+
+#endif /* _ASM_GENERIC_NOSPEC_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.43.0