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