1 // SPDX-License-Identifier: GPL-2.0 2 3 /****************************************************************************** 4 * Xen memory reservation utilities. 5 * 6 * Copyright (c) 2003, B Dragovic 7 * Copyright (c) 2003-2004, M Williamson, K Fraser 8 * Copyright (c) 2005 Dan M. Smith, IBM Corporation 9 * Copyright (c) 2010 Daniel Kiper 10 * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc. 11 */ 12 13 #include <asm/xen/hypercall.h> 14 15 #include <xen/interface/memory.h> 16 #include <xen/mem-reservation.h> 17 #include <linux/moduleparam.h> 18 19 bool __read_mostly xen_scrub_pages = IS_ENABLED(CONFIG_XEN_SCRUB_PAGES_DEFAULT); 20 core_param(xen_scrub_pages, xen_scrub_pages, bool, 0); 21 22 /* 23 * Use one extent per PAGE_SIZE to avoid to break down the page into 24 * multiple frame. 25 */ 26 #define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1) 27 28 #ifdef CONFIG_XEN_HAVE_PVMMU __xenmem_reservation_va_mapping_update(unsigned long count,struct page ** pages,xen_pfn_t * frames)29 void __xenmem_reservation_va_mapping_update(unsigned long count, 30 struct page **pages, 31 xen_pfn_t *frames) 32 { 33 int i; 34 35 for (i = 0; i < count; i++) { 36 struct page *page = pages[i]; 37 unsigned long pfn = page_to_pfn(page); 38 int ret; 39 40 BUG_ON(!page); 41 42 /* 43 * We don't support PV MMU when Linux and Xen is using 44 * different page granularity. 45 */ 46 BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); 47 48 set_phys_to_machine(pfn, frames[i]); 49 50 ret = HYPERVISOR_update_va_mapping( 51 (unsigned long)__va(pfn << PAGE_SHIFT), 52 mfn_pte(frames[i], PAGE_KERNEL), 0); 53 BUG_ON(ret); 54 } 55 } 56 EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_update); 57 __xenmem_reservation_va_mapping_reset(unsigned long count,struct page ** pages)58 void __xenmem_reservation_va_mapping_reset(unsigned long count, 59 struct page **pages) 60 { 61 int i; 62 63 for (i = 0; i < count; i++) { 64 struct page *page = pages[i]; 65 unsigned long pfn = page_to_pfn(page); 66 int ret; 67 68 /* 69 * We don't support PV MMU when Linux and Xen are using 70 * different page granularity. 71 */ 72 BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); 73 74 ret = HYPERVISOR_update_va_mapping( 75 (unsigned long)__va(pfn << PAGE_SHIFT), 76 __pte_ma(0), 0); 77 BUG_ON(ret); 78 79 __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); 80 } 81 } 82 EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_reset); 83 #endif /* CONFIG_XEN_HAVE_PVMMU */ 84 85 /* @frames is an array of PFNs */ xenmem_reservation_increase(int count,xen_pfn_t * frames)86 int xenmem_reservation_increase(int count, xen_pfn_t *frames) 87 { 88 struct xen_memory_reservation reservation = { 89 .address_bits = 0, 90 .extent_order = EXTENT_ORDER, 91 .domid = DOMID_SELF 92 }; 93 94 /* XENMEM_populate_physmap requires a PFN based on Xen granularity. */ 95 set_xen_guest_handle(reservation.extent_start, frames); 96 reservation.nr_extents = count; 97 return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation); 98 } 99 EXPORT_SYMBOL_GPL(xenmem_reservation_increase); 100 101 /* @frames is an array of GFNs */ xenmem_reservation_decrease(int count,xen_pfn_t * frames)102 int xenmem_reservation_decrease(int count, xen_pfn_t *frames) 103 { 104 struct xen_memory_reservation reservation = { 105 .address_bits = 0, 106 .extent_order = EXTENT_ORDER, 107 .domid = DOMID_SELF 108 }; 109 110 /* XENMEM_decrease_reservation requires a GFN */ 111 set_xen_guest_handle(reservation.extent_start, frames); 112 reservation.nr_extents = count; 113 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); 114 } 115 EXPORT_SYMBOL_GPL(xenmem_reservation_decrease); 116