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411d939db1
commit aa5a461171 upstream.
Introduce an x86 version of the cc_platform_has() function. This will be
used to replace vendor specific calls like sme_active(), sev_active(),
etc.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210928191009.32551-4-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
69 lines
1.7 KiB
C
69 lines
1.7 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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#include <linux/export.h>
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#include <linux/cc_platform.h>
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#include <linux/mem_encrypt.h>
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#include <asm/processor.h>
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static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr)
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{
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#ifdef CONFIG_INTEL_TDX_GUEST
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return false;
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#else
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return false;
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#endif
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}
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/*
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* SME and SEV are very similar but they are not the same, so there are
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* times that the kernel will need to distinguish between SME and SEV. The
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* cc_platform_has() function is used for this. When a distinction isn't
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* needed, the CC_ATTR_MEM_ENCRYPT attribute can be used.
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*
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* The trampoline code is a good example for this requirement. Before
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* paging is activated, SME will access all memory as decrypted, but SEV
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* will access all memory as encrypted. So, when APs are being brought
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* up under SME the trampoline area cannot be encrypted, whereas under SEV
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* the trampoline area must be encrypted.
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*/
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static bool amd_cc_platform_has(enum cc_attr attr)
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{
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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switch (attr) {
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case CC_ATTR_MEM_ENCRYPT:
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return sme_me_mask;
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case CC_ATTR_HOST_MEM_ENCRYPT:
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return sme_me_mask && !(sev_status & MSR_AMD64_SEV_ENABLED);
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case CC_ATTR_GUEST_MEM_ENCRYPT:
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return sev_status & MSR_AMD64_SEV_ENABLED;
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case CC_ATTR_GUEST_STATE_ENCRYPT:
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return sev_status & MSR_AMD64_SEV_ES_ENABLED;
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default:
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return false;
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}
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#else
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return false;
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#endif
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}
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bool cc_platform_has(enum cc_attr attr)
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{
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if (sme_me_mask)
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return amd_cc_platform_has(attr);
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return false;
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}
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EXPORT_SYMBOL_GPL(cc_platform_has);
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