From: Tom Lendacky thomas.lendacky@amd.com
stable inclusion from stable-5.10.80 commit 74ba917cfdddbb6b1ad9c2fc4833bf1f810b27f9 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 46b49b12f3fc5e1347dba37d4639e2165f447871 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/Kconfig | 3 ++ include/linux/cc_platform.h | 88 +++++++++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+) create mode 100644 include/linux/cc_platform.h
diff --git a/arch/Kconfig b/arch/Kconfig index 2bc2dea38ea4..7a8e3d45b2a1 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1074,6 +1074,9 @@ config RELR config ARCH_HAS_MEM_ENCRYPT bool
+config ARCH_HAS_CC_PLATFORM + bool + config HAVE_SPARSE_SYSCALL_NR bool help 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 @@ -0,0 +1,88 @@ +/* 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 */