1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Library for managing various aspects of guests 4 * 5 * Copyright (c) 2021 IBM Corp 6 * 7 * Authors: 8 * Janosch Frank <frankja@linux.ibm.com> 9 */ 10 11 #include <asm/barrier.h> 12 #include <bitops.h> 13 #include <libcflat.h> 14 #include <sie.h> 15 #include <asm/page.h> 16 #include <asm/interrupt.h> 17 #include <alloc_page.h> 18 #include <vmalloc.h> 19 #include <sclp.h> 20 21 void sie_expect_validity(struct vm *vm) 22 { 23 vm->validity_expected = true; 24 } 25 26 uint16_t sie_get_validity(struct vm *vm) 27 { 28 /* 29 * 0xffff will never be returned by SIE, so we can indicate a 30 * missing validity via this value. 31 */ 32 if (vm->sblk->icptcode != ICPT_VALIDITY) 33 return 0xffff; 34 35 return vm->sblk->ipb >> 16; 36 } 37 38 void sie_check_validity(struct vm *vm, uint16_t vir_exp) 39 { 40 uint16_t vir = sie_get_validity(vm); 41 42 report(vir_exp == vir, "VALIDITY: %x", vir); 43 } 44 45 void sie_handle_validity(struct vm *vm) 46 { 47 if (vm->sblk->icptcode != ICPT_VALIDITY) 48 return; 49 50 if (!vm->validity_expected) 51 report_abort("VALIDITY: %x", sie_get_validity(vm)); 52 vm->validity_expected = false; 53 } 54 55 void sie(struct vm *vm) 56 { 57 uint64_t old_cr13; 58 59 /* When a pgm int code is set, we'll never enter SIE below. */ 60 assert(!read_pgm_int_code()); 61 62 if (sie_is_pv(vm)) 63 memcpy(vm->sblk->pv_grregs, vm->save_area.guest.grs, 64 sizeof(vm->save_area.guest.grs)); 65 66 /* Reset icptcode so we don't trip over it below */ 67 vm->sblk->icptcode = 0; 68 69 /* 70 * Set up home address space to match primary space. Instead of running 71 * in home space all the time, we switch every time in sie() because: 72 * - tests that depend on running in primary space mode don't need to be 73 * touched 74 * - it avoids regressions in tests 75 * - switching every time makes it easier to extend this in the future, 76 * for example to allow tests to run in whatever space they want 77 */ 78 old_cr13 = stctg(13); 79 lctlg(13, stctg(1)); 80 81 /* switch to home space so guest tables can be different from host */ 82 psw_mask_set_bits(PSW_MASK_HOME); 83 84 /* also handle all interruptions in home space while in SIE */ 85 irq_set_dat_mode(true, AS_HOME); 86 87 /* leave SIE when we have an intercept or an interrupt so the test can react to it */ 88 while (vm->sblk->icptcode == 0 && !read_pgm_int_code()) { 89 sie64a(vm->sblk, &vm->save_area); 90 sie_handle_validity(vm); 91 } 92 vm->save_area.guest.grs[14] = vm->sblk->gg14; 93 vm->save_area.guest.grs[15] = vm->sblk->gg15; 94 95 irq_set_dat_mode(true, AS_PRIM); 96 psw_mask_clear_bits(PSW_MASK_HOME); 97 98 /* restore the old CR 13 */ 99 lctlg(13, old_cr13); 100 101 if (sie_is_pv(vm)) 102 memcpy(vm->save_area.guest.grs, vm->sblk->pv_grregs, 103 sizeof(vm->save_area.guest.grs)); 104 } 105 106 void sie_guest_sca_create(struct vm *vm) 107 { 108 vm->sca = (struct esca_block *)alloc_page(); 109 110 /* Let's start out with one page of ESCA for now */ 111 vm->sblk->scaoh = ((uint64_t)vm->sca >> 32); 112 vm->sblk->scaol = (uint64_t)vm->sca & ~0x3fU; 113 vm->sblk->ecb2 |= ECB2_ESCA; 114 115 /* Enable SIGP sense running interpretation */ 116 vm->sblk->ecb |= ECB_SRSI; 117 118 /* We assume that cpu 0 is always part of the vm */ 119 vm->sca->mcn[0] = BIT(63); 120 vm->sca->cpu[0].sda = (uint64_t)vm->sblk; 121 } 122 123 /* Initializes the struct vm members like the SIE control block. */ 124 void sie_guest_create(struct vm *vm, uint64_t guest_mem, uint64_t guest_mem_len) 125 { 126 vm->sblk = alloc_page(); 127 memset(vm->sblk, 0, PAGE_SIZE); 128 vm->sblk->cpuflags = CPUSTAT_ZARCH | CPUSTAT_RUNNING; 129 vm->sblk->ihcpu = 0xffff; 130 vm->sblk->prefix = 0; 131 132 /* Guest memory chunks are always 1MB */ 133 assert(!(guest_mem_len & ~HPAGE_MASK)); 134 vm->guest_mem = (uint8_t *)guest_mem; 135 /* For non-PV guests we re-use the host's ASCE for ease of use */ 136 vm->save_area.guest.asce = stctg(1); 137 /* Currently MSO/MSL is the easiest option */ 138 vm->sblk->mso = (uint64_t)guest_mem; 139 vm->sblk->msl = (uint64_t)guest_mem + ((guest_mem_len - 1) & HPAGE_MASK); 140 141 /* CRYCB needs to be in the first 2GB */ 142 vm->crycb = alloc_pages_flags(0, AREA_DMA31); 143 vm->sblk->crycbd = (uint32_t)(uintptr_t)vm->crycb; 144 } 145 146 /** 147 * sie_guest_alloc() - Allocate memory for a guest and map it in virtual address 148 * space such that it is properly aligned. 149 * @guest_size: the desired size of the guest in bytes. 150 */ 151 uint8_t *sie_guest_alloc(uint64_t guest_size) 152 { 153 static unsigned long guest_counter = 1; 154 u8 *guest_phys, *guest_virt; 155 unsigned long i; 156 pgd_t *root; 157 158 setup_vm(); 159 root = (pgd_t *)(stctg(1) & PAGE_MASK); 160 161 /* 162 * Start of guest memory in host virtual space needs to be aligned to 163 * 2GB for some environments. It also can't be at 2GB since the memory 164 * allocator stores its page_states metadata there. 165 * Thus we use the next multiple of 4GB after the end of physical 166 * mapping. This also leaves space after end of physical memory so the 167 * page immediately after physical memory is guaranteed not to be 168 * present. 169 */ 170 guest_virt = (uint8_t *)ALIGN(get_ram_size() + guest_counter * 4UL * SZ_1G, SZ_2G); 171 guest_counter++; 172 173 guest_phys = alloc_pages(get_order(guest_size) - 12); 174 /* 175 * Establish a new mapping of the guest memory so it can be 2GB aligned 176 * without actually requiring 2GB physical memory. 177 */ 178 for (i = 0; i < guest_size; i += PAGE_SIZE) { 179 install_page(root, __pa(guest_phys + i), guest_virt + i); 180 } 181 memset(guest_virt, 0, guest_size); 182 183 return guest_virt; 184 } 185 186 /* Frees the memory that was gathered on initialization */ 187 void sie_guest_destroy(struct vm *vm) 188 { 189 free_page(vm->crycb); 190 free_page(vm->sblk); 191 if (vm->sblk->ecb2 & ECB2_ESCA) 192 free_page(vm->sca); 193 } 194