forked from mirrors/linux
8260b9820f
INS/OUTS are not supported in TDX guests and cause #UD. Kernel has to avoid them when running in TDX guest. To support existing usage, string I/O operations are unrolled using IN/OUT instructions. AMD SEV platform implements this support by adding unroll logic in ins#bwl()/outs#bwl() macros with SEV-specific checks. Since TDX VM guests will also need similar support, use CC_ATTR_GUEST_UNROLL_STRING_IO and generic cc_platform_has() API to implement it. String I/O helpers were the last users of sev_key_active() interface and sev_enable_key static key. Remove them. [ bp: Move comment too and do not delete it. ] Suggested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20211206135505.75045-2-kirill.shutemov@linux.intel.com
99 lines
2.6 KiB
C
99 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Confidential Computing Platform Capability checks
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*
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* Copyright (C) 2021 Advanced Micro Devices, Inc.
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*
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* Author: Tom Lendacky <thomas.lendacky@amd.com>
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*/
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#ifndef _LINUX_CC_PLATFORM_H
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#define _LINUX_CC_PLATFORM_H
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#include <linux/types.h>
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#include <linux/stddef.h>
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/**
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* enum cc_attr - Confidential computing attributes
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*
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* These attributes represent confidential computing features that are
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* currently active.
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*/
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enum cc_attr {
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/**
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* @CC_ATTR_MEM_ENCRYPT: Memory encryption is active
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*
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* The platform/OS is running with active memory encryption. This
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* includes running either as a bare-metal system or a hypervisor
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* and actively using memory encryption or as a guest/virtual machine
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* and actively using memory encryption.
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*
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* Examples include SME, SEV and SEV-ES.
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*/
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CC_ATTR_MEM_ENCRYPT,
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/**
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* @CC_ATTR_HOST_MEM_ENCRYPT: Host memory encryption is active
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*
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* The platform/OS is running as a bare-metal system or a hypervisor
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* and actively using memory encryption.
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*
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* Examples include SME.
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*/
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CC_ATTR_HOST_MEM_ENCRYPT,
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/**
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* @CC_ATTR_GUEST_MEM_ENCRYPT: Guest memory encryption is active
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*
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* The platform/OS is running as a guest/virtual machine and actively
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* using memory encryption.
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*
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* Examples include SEV and SEV-ES.
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*/
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CC_ATTR_GUEST_MEM_ENCRYPT,
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/**
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* @CC_ATTR_GUEST_STATE_ENCRYPT: Guest state encryption is active
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*
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* The platform/OS is running as a guest/virtual machine and actively
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* using memory encryption and register state encryption.
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*
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* Examples include SEV-ES.
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*/
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CC_ATTR_GUEST_STATE_ENCRYPT,
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/**
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* @CC_ATTR_GUEST_UNROLL_STRING_IO: String I/O is implemented with
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* IN/OUT instructions
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*
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* The platform/OS is running as a guest/virtual machine and uses
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* IN/OUT instructions in place of string I/O.
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*
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* Examples include TDX guest & SEV.
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*/
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CC_ATTR_GUEST_UNROLL_STRING_IO,
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};
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#ifdef CONFIG_ARCH_HAS_CC_PLATFORM
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/**
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* cc_platform_has() - Checks if the specified cc_attr attribute is active
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* @attr: Confidential computing attribute to check
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*
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* The cc_platform_has() function will return an indicator as to whether the
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* specified Confidential Computing attribute is currently active.
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*
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* Context: Any context
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* Return:
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* * TRUE - Specified Confidential Computing attribute is active
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* * FALSE - Specified Confidential Computing attribute is not active
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*/
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bool cc_platform_has(enum cc_attr attr);
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#else /* !CONFIG_ARCH_HAS_CC_PLATFORM */
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static inline bool cc_platform_has(enum cc_attr attr) { return false; }
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#endif /* CONFIG_ARCH_HAS_CC_PLATFORM */
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#endif /* _LINUX_CC_PLATFORM_H */
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