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1// SPDX-License-Identifier: GPL-2.02 3/******************************************************************************4 * Xen memory reservation utilities.5 *6 * Copyright (c) 2003, B Dragovic7 * Copyright (c) 2003-2004, M Williamson, K Fraser8 * Copyright (c) 2005 Dan M. Smith, IBM Corporation9 * Copyright (c) 2010 Daniel Kiper10 * 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 19bool __read_mostly xen_scrub_pages = IS_ENABLED(CONFIG_XEN_SCRUB_PAGES_DEFAULT);20core_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 into24 * multiple frame.25 */26#define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1)27 28#ifdef CONFIG_XEN_HAVE_PVMMU29void __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 using44 * 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}56EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_update);57 58void __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 using70 * 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}82EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_reset);83#endif /* CONFIG_XEN_HAVE_PVMMU */84 85/* @frames is an array of PFNs */86int 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_SELF92 };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}99EXPORT_SYMBOL_GPL(xenmem_reservation_increase);100 101/* @frames is an array of GFNs */102int 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_SELF108 };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}115EXPORT_SYMBOL_GPL(xenmem_reservation_decrease);116