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 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 */ 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 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 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 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 } 106 107 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