1 // SPDX-License-Identifier: GPL-2.0-only
3 * Memory Encryption Support Common Code
5 * Copyright (C) 2016 Advanced Micro Devices, Inc.
7 * Author: Tom Lendacky <thomas.lendacky@amd.com>
10 #include <linux/dma-direct.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/swiotlb.h>
13 #include <linux/cc_platform.h>
14 #include <linux/mem_encrypt.h>
15 #include <linux/virtio_config.h>
17 /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
18 bool force_dma_unencrypted(struct device *dev)
21 * For SEV, all DMA must be to unencrypted addresses.
23 if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
27 * For SME, all DMA must be to unencrypted addresses if the
28 * device does not support DMA to addresses that include the
31 if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
32 u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
33 u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
36 if (dma_dev_mask <= dma_enc_mask)
43 static void print_mem_encrypt_feature_info(void)
45 pr_info("Memory Encryption Features active:");
47 if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) {
48 pr_cont(" Intel TDX\n");
54 /* Secure Memory Encryption */
55 if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
57 * SME is mutually exclusive with any of the SEV
64 /* Secure Encrypted Virtualization */
65 if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
68 /* Encrypted Register State */
69 if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
72 /* Secure Nested Paging */
73 if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
79 /* Architecture __weak replacement functions */
80 void __init mem_encrypt_init(void)
82 if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
85 /* Call into SWIOTLB to update the SWIOTLB DMA buffers */
86 swiotlb_update_mem_attributes();
88 print_mem_encrypt_feature_info();
91 int arch_has_restricted_virtio_memory_access(void)
93 return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
95 EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);