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
init_svm(void)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 swiotlb_force = 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 /*
41 * Initialize SWIOTLB. Essentially the same as swiotlb_init(), except that it
42 * can allocate the buffer anywhere in memory. Since the hypervisor doesn't have
43 * any addressing limitation, we don't need to allocate it in low addresses.
44 */
svm_swiotlb_init(void)45 void __init svm_swiotlb_init(void)
46 {
47 unsigned char *vstart;
48 unsigned long bytes, io_tlb_nslabs;
49
50 io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT);
51 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
52
53 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
54
55 vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE);
56 if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
57 return;
58
59
60 memblock_free(vstart, PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
61 panic("SVM: Cannot allocate SWIOTLB buffer");
62 }
63
set_memory_encrypted(unsigned long addr,int numpages)64 int set_memory_encrypted(unsigned long addr, int numpages)
65 {
66 if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
67 return 0;
68
69 if (!PAGE_ALIGNED(addr))
70 return -EINVAL;
71
72 uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
73
74 return 0;
75 }
76
set_memory_decrypted(unsigned long addr,int numpages)77 int set_memory_decrypted(unsigned long addr, int numpages)
78 {
79 if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
80 return 0;
81
82 if (!PAGE_ALIGNED(addr))
83 return -EINVAL;
84
85 uv_share_page(PHYS_PFN(__pa(addr)), numpages);
86
87 return 0;
88 }
89
90 /* There's one dispatch log per CPU. */
91 #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
92
93 static struct page *dtl_page_store[NR_DTL_PAGE];
94 static long dtl_nr_pages;
95
is_dtl_page_shared(struct page * page)96 static bool is_dtl_page_shared(struct page *page)
97 {
98 long i;
99
100 for (i = 0; i < dtl_nr_pages; i++)
101 if (dtl_page_store[i] == page)
102 return true;
103
104 return false;
105 }
106
dtl_cache_ctor(void * addr)107 void dtl_cache_ctor(void *addr)
108 {
109 unsigned long pfn = PHYS_PFN(__pa(addr));
110 struct page *page = pfn_to_page(pfn);
111
112 if (!is_dtl_page_shared(page)) {
113 dtl_page_store[dtl_nr_pages] = page;
114 dtl_nr_pages++;
115 WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
116 uv_share_page(pfn, 1);
117 }
118 }
119