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authorTom Lendacky <thomas.lendacky@amd.com>2021-09-09 01:58:33 +0300
committerBorislav Petkov <bp@suse.de>2021-10-04 12:46:05 +0300
commit46b49b12f3fc5e1347dba37d4639e2165f447871 (patch)
tree65f7081893383c93ba69708bd62545d46c27d1cd /include/linux/cc_platform.h
parent402fe0cb71032c4bc931ac70a6b024408e09f817 (diff)
downloadlinux-46b49b12f3fc5e1347dba37d4639e2165f447871.tar.xz
arch/cc: Introduce a function to check for confidential computing features
In preparation for other confidential computing technologies, introduce a generic helper function, cc_platform_has(), that can be used to check for specific active confidential computing 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() || ... ). [ bp: s/_CC_PLATFORM_H/_LINUX_CC_PLATFORM_H/g ] Co-developed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210928191009.32551-3-bp@alien8.de
Diffstat (limited to 'include/linux/cc_platform.h')
-rw-r--r--include/linux/cc_platform.h88
1 files changed, 88 insertions, 0 deletions
diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h
new file mode 100644
index 000000000000..a075b70b9a70
--- /dev/null
+++ b/include/linux/cc_platform.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Confidential Computing Platform Capability checks
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#ifndef _LINUX_CC_PLATFORM_H
+#define _LINUX_CC_PLATFORM_H
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+
+/**
+ * enum cc_attr - Confidential computing attributes
+ *
+ * These attributes represent confidential computing features that are
+ * currently active.
+ */
+enum cc_attr {
+ /**
+ * @CC_ATTR_MEM_ENCRYPT: Memory encryption is active
+ *
+ * The platform/OS is running with active memory encryption. This
+ * includes running either as a bare-metal system or a hypervisor
+ * and actively using memory encryption or as a guest/virtual machine
+ * and actively using memory encryption.
+ *
+ * Examples include SME, SEV and SEV-ES.
+ */
+ CC_ATTR_MEM_ENCRYPT,
+
+ /**
+ * @CC_ATTR_HOST_MEM_ENCRYPT: Host memory encryption is active
+ *
+ * The platform/OS is running as a bare-metal system or a hypervisor
+ * and actively using memory encryption.
+ *
+ * Examples include SME.
+ */
+ CC_ATTR_HOST_MEM_ENCRYPT,
+
+ /**
+ * @CC_ATTR_GUEST_MEM_ENCRYPT: Guest memory encryption is active
+ *
+ * The platform/OS is running as a guest/virtual machine and actively
+ * using memory encryption.
+ *
+ * Examples include SEV and SEV-ES.
+ */
+ CC_ATTR_GUEST_MEM_ENCRYPT,
+
+ /**
+ * @CC_ATTR_GUEST_STATE_ENCRYPT: Guest state encryption is active
+ *
+ * The platform/OS is running as a guest/virtual machine and actively
+ * using memory encryption and register state encryption.
+ *
+ * Examples include SEV-ES.
+ */
+ CC_ATTR_GUEST_STATE_ENCRYPT,
+};
+
+#ifdef CONFIG_ARCH_HAS_CC_PLATFORM
+
+/**
+ * cc_platform_has() - Checks if the specified cc_attr attribute is active
+ * @attr: Confidential computing attribute to check
+ *
+ * The cc_platform_has() function will return an indicator as to whether the
+ * specified Confidential Computing attribute is currently active.
+ *
+ * Context: Any context
+ * Return:
+ * * TRUE - Specified Confidential Computing attribute is active
+ * * FALSE - Specified Confidential Computing attribute is not active
+ */
+bool cc_platform_has(enum cc_attr attr);
+
+#else /* !CONFIG_ARCH_HAS_CC_PLATFORM */
+
+static inline bool cc_platform_has(enum cc_attr attr) { return false; }
+
+#endif /* CONFIG_ARCH_HAS_CC_PLATFORM */
+
+#endif /* _LINUX_CC_PLATFORM_H */