In prep for other protected virtualization technologies, introduce a
generic helper function, prot_guest_has(), that can be used to check
for specific protection attributes, like memory encryption. This is
intended to eliminate having to add multiple technology-specific checks
to the code (e.g. if (sev_active() || tdx_active())).
Co-developed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/Kconfig | 3 +++
include/linux/protected_guest.h | 32 ++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
create mode 100644 include/linux/protected_guest.h
diff --git a/arch/Kconfig b/arch/Kconfig
index 129df498a8e1..a47cf283f2ff 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1231,6 +1231,9 @@ config RELR
config ARCH_HAS_MEM_ENCRYPT
bool
+config ARCH_HAS_PROTECTED_GUEST
+ bool
+
config HAVE_SPARSE_SYSCALL_NR
bool
help
diff --git a/include/linux/protected_guest.h b/include/linux/protected_guest.h
new file mode 100644
index 000000000000..f8ed7b72967b
--- /dev/null
+++ b/include/linux/protected_guest.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Protected Guest (and Host) Capability checks
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@xxxxxxx>
+ */
+
+#ifndef _PROTECTED_GUEST_H
+#define _PROTECTED_GUEST_H
+
+#ifndef __ASSEMBLY__
+
+#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */
+#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */
+#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */
+#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */
+
+#ifdef CONFIG_ARCH_HAS_PROTECTED_GUEST
+
+#include <asm/protected_guest.h>
+
+#else /* !CONFIG_ARCH_HAS_PROTECTED_GUEST */
+
+static inline bool prot_guest_has(unsigned int attr) { return false; }
+
+#endif /* CONFIG_ARCH_HAS_PROTECTED_GUEST */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _PROTECTED_GUEST_H */
--
2.32.0
