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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Secure VM platform
4 *
5 * Copyright 2018 IBM Corporation
6 * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
7 */
8
9#include <linux/mm.h>
10#include <linux/memblock.h>
11#include <linux/mem_encrypt.h>
12#include <linux/cc_platform.h>
13#include <asm/machdep.h>
14#include <asm/svm.h>
15#include <asm/swiotlb.h>
16#include <asm/ultravisor.h>
17#include <asm/dtl.h>
18
19static int __init init_svm(void)
20{
21 if (!is_secure_guest())
22 return 0;
23
24 /* Don't release the SWIOTLB buffer. */
25 ppc_swiotlb_enable = 1;
26
27 /*
28 * Since the guest memory is inaccessible to the host, devices always
29 * need to use the SWIOTLB buffer for DMA even if dma_capable() says
30 * otherwise.
31 */
32 ppc_swiotlb_flags |= SWIOTLB_ANY | SWIOTLB_FORCE;
33
34 /* Share the SWIOTLB buffer with the host. */
35 swiotlb_update_mem_attributes();
36
37 return 0;
38}
39machine_early_initcall(pseries, init_svm);
40
41int set_memory_encrypted(unsigned long addr, int numpages)
42{
43 if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
44 return 0;
45
46 if (!PAGE_ALIGNED(addr))
47 return -EINVAL;
48
49 uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
50
51 return 0;
52}
53
54int set_memory_decrypted(unsigned long addr, int numpages)
55{
56 if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
57 return 0;
58
59 if (!PAGE_ALIGNED(addr))
60 return -EINVAL;
61
62 uv_share_page(PHYS_PFN(__pa(addr)), numpages);
63
64 return 0;
65}
66
67/* There's one dispatch log per CPU. */
68#define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
69
70static struct page *dtl_page_store[NR_DTL_PAGE];
71static long dtl_nr_pages;
72
73static bool is_dtl_page_shared(struct page *page)
74{
75 long i;
76
77 for (i = 0; i < dtl_nr_pages; i++)
78 if (dtl_page_store[i] == page)
79 return true;
80
81 return false;
82}
83
84void dtl_cache_ctor(void *addr)
85{
86 unsigned long pfn = PHYS_PFN(__pa(addr));
87 struct page *page = pfn_to_page(pfn);
88
89 if (!is_dtl_page_shared(page)) {
90 dtl_page_store[dtl_nr_pages] = page;
91 dtl_nr_pages++;
92 WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
93 uv_share_page(pfn, 1);
94 }
95}