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 <asm/machdep.h> 12 #include <asm/svm.h> 13 #include <asm/swiotlb.h> 14 #include <asm/ultravisor.h> 15 #include <asm/dtl.h> 16 17 static int __init init_svm(void) 18 { 19 if (!is_secure_guest()) 20 return 0; 21 22 /* Don't release the SWIOTLB buffer. */ 23 ppc_swiotlb_enable = 1; 24 25 /* 26 * Since the guest memory is inaccessible to the host, devices always 27 * need to use the SWIOTLB buffer for DMA even if dma_capable() says 28 * otherwise. 29 */ 30 swiotlb_force = SWIOTLB_FORCE; 31 32 /* Share the SWIOTLB buffer with the host. */ 33 swiotlb_update_mem_attributes(); 34 35 return 0; 36 } 37 machine_early_initcall(pseries, init_svm); 38 39 /* 40 * Initialize SWIOTLB. Essentially the same as swiotlb_init(), except that it 41 * can allocate the buffer anywhere in memory. Since the hypervisor doesn't have 42 * any addressing limitation, we don't need to allocate it in low addresses. 43 */ 44 void __init svm_swiotlb_init(void) 45 { 46 unsigned char *vstart; 47 unsigned long bytes, io_tlb_nslabs; 48 49 io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT); 50 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); 51 52 bytes = io_tlb_nslabs << IO_TLB_SHIFT; 53 54 vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE); 55 if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false)) 56 return; 57 58 59 memblock_free(vstart, PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); 60 panic("SVM: Cannot allocate SWIOTLB buffer"); 61 } 62 63 int set_memory_encrypted(unsigned long addr, int numpages) 64 { 65 if (!mem_encrypt_active()) 66 return 0; 67 68 if (!PAGE_ALIGNED(addr)) 69 return -EINVAL; 70 71 uv_unshare_page(PHYS_PFN(__pa(addr)), numpages); 72 73 return 0; 74 } 75 76 int set_memory_decrypted(unsigned long addr, int numpages) 77 { 78 if (!mem_encrypt_active()) 79 return 0; 80 81 if (!PAGE_ALIGNED(addr)) 82 return -EINVAL; 83 84 uv_share_page(PHYS_PFN(__pa(addr)), numpages); 85 86 return 0; 87 } 88 89 /* There's one dispatch log per CPU. */ 90 #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE) 91 92 static struct page *dtl_page_store[NR_DTL_PAGE]; 93 static long dtl_nr_pages; 94 95 static bool is_dtl_page_shared(struct page *page) 96 { 97 long i; 98 99 for (i = 0; i < dtl_nr_pages; i++) 100 if (dtl_page_store[i] == page) 101 return true; 102 103 return false; 104 } 105 106 void dtl_cache_ctor(void *addr) 107 { 108 unsigned long pfn = PHYS_PFN(__pa(addr)); 109 struct page *page = pfn_to_page(pfn); 110 111 if (!is_dtl_page_shared(page)) { 112 dtl_page_store[dtl_nr_pages] = page; 113 dtl_nr_pages++; 114 WARN_ON(dtl_nr_pages >= NR_DTL_PAGE); 115 uv_share_page(pfn, 1); 116 } 117 } 118