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