1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Hosting Protected Virtual Machines 4 * 5 * Copyright IBM Corp. 2019, 2020 6 * Author(s): Janosch Frank <frankja@linux.ibm.com> 7 */ 8 #include <linux/kvm.h> 9 #include <linux/kvm_host.h> 10 #include <linux/pagemap.h> 11 #include <linux/sched/signal.h> 12 #include <asm/gmap.h> 13 #include <asm/uv.h> 14 #include <asm/mman.h> 15 #include "kvm-s390.h" 16 17 int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) 18 { 19 int cc; 20 21 if (!kvm_s390_pv_cpu_get_handle(vcpu)) 22 return 0; 23 24 cc = uv_cmd_nodata(kvm_s390_pv_cpu_get_handle(vcpu), UVC_CMD_DESTROY_SEC_CPU, rc, rrc); 25 26 KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT DESTROY VCPU %d: rc %x rrc %x", 27 vcpu->vcpu_id, *rc, *rrc); 28 WARN_ONCE(cc, "protvirt destroy cpu failed rc %x rrc %x", *rc, *rrc); 29 30 /* Intended memory leak for something that should never happen. */ 31 if (!cc) 32 free_pages(vcpu->arch.pv.stor_base, 33 get_order(uv_info.guest_cpu_stor_len)); 34 35 free_page(sida_origin(vcpu->arch.sie_block)); 36 vcpu->arch.sie_block->pv_handle_cpu = 0; 37 vcpu->arch.sie_block->pv_handle_config = 0; 38 memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv)); 39 vcpu->arch.sie_block->sdf = 0; 40 /* 41 * The sidad field (for sdf == 2) is now the gbea field (for sdf == 0). 42 * Use the reset value of gbea to avoid leaking the kernel pointer of 43 * the just freed sida. 44 */ 45 vcpu->arch.sie_block->gbea = 1; 46 kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); 47 48 return cc ? EIO : 0; 49 } 50 51 int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) 52 { 53 struct uv_cb_csc uvcb = { 54 .header.cmd = UVC_CMD_CREATE_SEC_CPU, 55 .header.len = sizeof(uvcb), 56 }; 57 int cc; 58 59 if (kvm_s390_pv_cpu_get_handle(vcpu)) 60 return -EINVAL; 61 62 vcpu->arch.pv.stor_base = __get_free_pages(GFP_KERNEL_ACCOUNT, 63 get_order(uv_info.guest_cpu_stor_len)); 64 if (!vcpu->arch.pv.stor_base) 65 return -ENOMEM; 66 67 /* Input */ 68 uvcb.guest_handle = kvm_s390_pv_get_handle(vcpu->kvm); 69 uvcb.num = vcpu->arch.sie_block->icpua; 70 uvcb.state_origin = (u64)vcpu->arch.sie_block; 71 uvcb.stor_origin = (u64)vcpu->arch.pv.stor_base; 72 73 /* Alloc Secure Instruction Data Area Designation */ 74 vcpu->arch.sie_block->sidad = __get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); 75 if (!vcpu->arch.sie_block->sidad) { 76 free_pages(vcpu->arch.pv.stor_base, 77 get_order(uv_info.guest_cpu_stor_len)); 78 return -ENOMEM; 79 } 80 81 cc = uv_call(0, (u64)&uvcb); 82 *rc = uvcb.header.rc; 83 *rrc = uvcb.header.rrc; 84 KVM_UV_EVENT(vcpu->kvm, 3, 85 "PROTVIRT CREATE VCPU: cpu %d handle %llx rc %x rrc %x", 86 vcpu->vcpu_id, uvcb.cpu_handle, uvcb.header.rc, 87 uvcb.header.rrc); 88 89 if (cc) { 90 u16 dummy; 91 92 kvm_s390_pv_destroy_cpu(vcpu, &dummy, &dummy); 93 return -EIO; 94 } 95 96 /* Output */ 97 vcpu->arch.pv.handle = uvcb.cpu_handle; 98 vcpu->arch.sie_block->pv_handle_cpu = uvcb.cpu_handle; 99 vcpu->arch.sie_block->pv_handle_config = kvm_s390_pv_get_handle(vcpu->kvm); 100 vcpu->arch.sie_block->sdf = 2; 101 kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); 102 return 0; 103 } 104 105 /* only free resources when the destroy was successful */ 106 static void kvm_s390_pv_dealloc_vm(struct kvm *kvm) 107 { 108 vfree(kvm->arch.pv.stor_var); 109 free_pages(kvm->arch.pv.stor_base, 110 get_order(uv_info.guest_base_stor_len)); 111 memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv)); 112 } 113 114 static int kvm_s390_pv_alloc_vm(struct kvm *kvm) 115 { 116 unsigned long base = uv_info.guest_base_stor_len; 117 unsigned long virt = uv_info.guest_virt_var_stor_len; 118 unsigned long npages = 0, vlen = 0; 119 120 kvm->arch.pv.stor_var = NULL; 121 kvm->arch.pv.stor_base = __get_free_pages(GFP_KERNEL_ACCOUNT, get_order(base)); 122 if (!kvm->arch.pv.stor_base) 123 return -ENOMEM; 124 125 /* 126 * Calculate current guest storage for allocation of the 127 * variable storage, which is based on the length in MB. 128 * 129 * Slots are sorted by GFN 130 */ 131 mutex_lock(&kvm->slots_lock); 132 npages = kvm_s390_get_gfn_end(kvm_memslots(kvm)); 133 mutex_unlock(&kvm->slots_lock); 134 135 kvm->arch.pv.guest_len = npages * PAGE_SIZE; 136 137 /* Allocate variable storage */ 138 vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE); 139 vlen += uv_info.guest_virt_base_stor_len; 140 /* 141 * The Create Secure Configuration Ultravisor Call does not support 142 * using large pages for the virtual memory area. 143 * This is a hardware limitation. 144 */ 145 kvm->arch.pv.stor_var = vmalloc_no_huge(vlen); 146 if (!kvm->arch.pv.stor_var) 147 goto out_err; 148 return 0; 149 150 out_err: 151 kvm_s390_pv_dealloc_vm(kvm); 152 return -ENOMEM; 153 } 154 155 /* this should not fail, but if it does, we must not free the donated memory */ 156 int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc) 157 { 158 int cc; 159 160 /* make all pages accessible before destroying the guest */ 161 s390_reset_acc(kvm->mm); 162 163 cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm), 164 UVC_CMD_DESTROY_SEC_CONF, rc, rrc); 165 WRITE_ONCE(kvm->arch.gmap->guest_handle, 0); 166 atomic_set(&kvm->mm->context.is_protected, 0); 167 KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc); 168 WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc); 169 /* Inteded memory leak on "impossible" error */ 170 if (!cc) 171 kvm_s390_pv_dealloc_vm(kvm); 172 return cc ? -EIO : 0; 173 } 174 175 int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc) 176 { 177 struct uv_cb_cgc uvcb = { 178 .header.cmd = UVC_CMD_CREATE_SEC_CONF, 179 .header.len = sizeof(uvcb) 180 }; 181 int cc, ret; 182 u16 dummy; 183 184 ret = kvm_s390_pv_alloc_vm(kvm); 185 if (ret) 186 return ret; 187 188 /* Inputs */ 189 uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */ 190 uvcb.guest_stor_len = kvm->arch.pv.guest_len; 191 uvcb.guest_asce = kvm->arch.gmap->asce; 192 uvcb.guest_sca = (unsigned long)kvm->arch.sca; 193 uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base; 194 uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var; 195 196 cc = uv_call_sched(0, (u64)&uvcb); 197 *rc = uvcb.header.rc; 198 *rrc = uvcb.header.rrc; 199 KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x", 200 uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc); 201 202 /* Outputs */ 203 kvm->arch.pv.handle = uvcb.guest_handle; 204 205 if (cc) { 206 if (uvcb.header.rc & UVC_RC_NEED_DESTROY) 207 kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy); 208 else 209 kvm_s390_pv_dealloc_vm(kvm); 210 return -EIO; 211 } 212 kvm->arch.gmap->guest_handle = uvcb.guest_handle; 213 return 0; 214 } 215 216 int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc, 217 u16 *rrc) 218 { 219 struct uv_cb_ssc uvcb = { 220 .header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS, 221 .header.len = sizeof(uvcb), 222 .sec_header_origin = (u64)hdr, 223 .sec_header_len = length, 224 .guest_handle = kvm_s390_pv_get_handle(kvm), 225 }; 226 int cc = uv_call(0, (u64)&uvcb); 227 228 *rc = uvcb.header.rc; 229 *rrc = uvcb.header.rrc; 230 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x", 231 *rc, *rrc); 232 if (!cc) 233 atomic_set(&kvm->mm->context.is_protected, 1); 234 return cc ? -EINVAL : 0; 235 } 236 237 static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak, 238 u64 offset, u16 *rc, u16 *rrc) 239 { 240 struct uv_cb_unp uvcb = { 241 .header.cmd = UVC_CMD_UNPACK_IMG, 242 .header.len = sizeof(uvcb), 243 .guest_handle = kvm_s390_pv_get_handle(kvm), 244 .gaddr = addr, 245 .tweak[0] = tweak, 246 .tweak[1] = offset, 247 }; 248 int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb); 249 250 *rc = uvcb.header.rc; 251 *rrc = uvcb.header.rrc; 252 253 if (ret && ret != -EAGAIN) 254 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x", 255 uvcb.gaddr, *rc, *rrc); 256 return ret; 257 } 258 259 int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size, 260 unsigned long tweak, u16 *rc, u16 *rrc) 261 { 262 u64 offset = 0; 263 int ret = 0; 264 265 if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK) 266 return -EINVAL; 267 268 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx", 269 addr, size); 270 271 while (offset < size) { 272 ret = unpack_one(kvm, addr, tweak, offset, rc, rrc); 273 if (ret == -EAGAIN) { 274 cond_resched(); 275 if (fatal_signal_pending(current)) 276 break; 277 continue; 278 } 279 if (ret) 280 break; 281 addr += PAGE_SIZE; 282 offset += PAGE_SIZE; 283 } 284 if (!ret) 285 KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful"); 286 return ret; 287 } 288 289 int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state) 290 { 291 struct uv_cb_cpu_set_state uvcb = { 292 .header.cmd = UVC_CMD_CPU_SET_STATE, 293 .header.len = sizeof(uvcb), 294 .cpu_handle = kvm_s390_pv_cpu_get_handle(vcpu), 295 .state = state, 296 }; 297 int cc; 298 299 cc = uv_call(0, (u64)&uvcb); 300 KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x", 301 vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc); 302 if (cc) 303 return -EINVAL; 304 return 0; 305 } 306