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 	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 
set_memory_encrypted(unsigned long addr,int numpages)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 
set_memory_decrypted(unsigned long addr,int numpages)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 
is_dtl_page_shared(struct page * page)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 
dtl_cache_ctor(void * addr)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