97 lines
2.3 KiB
C
97 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Memory Encryption Support Common Code
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*
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* Copyright (C) 2016 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/dma-direct.h>
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#include <linux/dma-mapping.h>
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#include <linux/swiotlb.h>
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#include <linux/cc_platform.h>
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#include <linux/mem_encrypt.h>
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#include <linux/virtio_config.h>
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/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
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bool force_dma_unencrypted(struct device *dev)
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{
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/*
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* For SEV, all DMA must be to unencrypted addresses.
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*/
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if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
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return true;
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/*
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* For SME, all DMA must be to unencrypted addresses if the
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* device does not support DMA to addresses that include the
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* encryption mask.
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*/
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if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
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u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
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u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
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dev->bus_dma_limit);
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if (dma_dev_mask <= dma_enc_mask)
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return true;
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}
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return false;
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}
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static void print_mem_encrypt_feature_info(void)
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{
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pr_info("Memory Encryption Features active:");
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if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) {
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mark_tech_preview("Intel Trusted Domain Extensions (TDX)", NULL);
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pr_cont(" Intel TDX\n");
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return;
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}
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pr_cont(" AMD");
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/* Secure Memory Encryption */
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if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
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/*
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* SME is mutually exclusive with any of the SEV
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* features below.
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*/
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pr_cont(" SME\n");
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return;
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}
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/* Secure Encrypted Virtualization */
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if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
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pr_cont(" SEV");
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/* Encrypted Register State */
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if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
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pr_cont(" SEV-ES");
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/* Secure Nested Paging */
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if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
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pr_cont(" SEV-SNP");
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pr_cont("\n");
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}
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/* Architecture __weak replacement functions */
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void __init mem_encrypt_init(void)
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{
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if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
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return;
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/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
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swiotlb_update_mem_attributes();
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print_mem_encrypt_feature_info();
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}
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int arch_has_restricted_virtio_memory_access(void)
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{
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return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
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}
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EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);
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