1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * handling diagnose instructions 4 * 5 * Copyright IBM Corp. 2008, 2011 6 * 7 * Author(s): Carsten Otte <cotte@de.ibm.com> 8 * Christian Borntraeger <borntraeger@de.ibm.com> 9 */ 10 11 #include <linux/kvm.h> 12 #include <linux/kvm_host.h> 13 #include <asm/pgalloc.h> 14 #include <asm/gmap.h> 15 #include <asm/virtio-ccw.h> 16 #include "kvm-s390.h" 17 #include "trace.h" 18 #include "trace-s390.h" 19 #include "gaccess.h" 20 21 static int diag_release_pages(struct kvm_vcpu *vcpu) 22 { 23 unsigned long start, end; 24 unsigned long prefix = kvm_s390_get_prefix(vcpu); 25 26 start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4]; 27 end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + PAGE_SIZE; 28 vcpu->stat.diagnose_10++; 29 30 if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end 31 || start < 2 * PAGE_SIZE) 32 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 33 34 VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end); 35 36 /* 37 * We checked for start >= end above, so lets check for the 38 * fast path (no prefix swap page involved) 39 */ 40 if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) { 41 gmap_discard(vcpu->arch.gmap, start, end); 42 } else { 43 /* 44 * This is slow path. gmap_discard will check for start 45 * so lets split this into before prefix, prefix, after 46 * prefix and let gmap_discard make some of these calls 47 * NOPs. 48 */ 49 gmap_discard(vcpu->arch.gmap, start, prefix); 50 if (start <= prefix) 51 gmap_discard(vcpu->arch.gmap, 0, PAGE_SIZE); 52 if (end > prefix + PAGE_SIZE) 53 gmap_discard(vcpu->arch.gmap, PAGE_SIZE, 2 * PAGE_SIZE); 54 gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end); 55 } 56 return 0; 57 } 58 59 static int __diag_page_ref_service(struct kvm_vcpu *vcpu) 60 { 61 struct prs_parm { 62 u16 code; 63 u16 subcode; 64 u16 parm_len; 65 u16 parm_version; 66 u64 token_addr; 67 u64 select_mask; 68 u64 compare_mask; 69 u64 zarch; 70 }; 71 struct prs_parm parm; 72 int rc; 73 u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4; 74 u16 ry = (vcpu->arch.sie_block->ipa & 0x0f); 75 76 VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx", 77 vcpu->run->s.regs.gprs[rx]); 78 vcpu->stat.diagnose_258++; 79 if (vcpu->run->s.regs.gprs[rx] & 7) 80 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 81 rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm)); 82 if (rc) 83 return kvm_s390_inject_prog_cond(vcpu, rc); 84 if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258) 85 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 86 87 switch (parm.subcode) { 88 case 0: /* TOKEN */ 89 VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx " 90 "select mask 0x%llx compare mask 0x%llx", 91 parm.token_addr, parm.select_mask, parm.compare_mask); 92 if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) { 93 /* 94 * If the pagefault handshake is already activated, 95 * the token must not be changed. We have to return 96 * decimal 8 instead, as mandated in SC24-6084. 97 */ 98 vcpu->run->s.regs.gprs[ry] = 8; 99 return 0; 100 } 101 102 if ((parm.compare_mask & parm.select_mask) != parm.compare_mask || 103 parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL) 104 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 105 106 if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr)) 107 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 108 109 vcpu->arch.pfault_token = parm.token_addr; 110 vcpu->arch.pfault_select = parm.select_mask; 111 vcpu->arch.pfault_compare = parm.compare_mask; 112 vcpu->run->s.regs.gprs[ry] = 0; 113 rc = 0; 114 break; 115 case 1: /* 116 * CANCEL 117 * Specification allows to let already pending tokens survive 118 * the cancel, therefore to reduce code complexity, we assume 119 * all outstanding tokens are already pending. 120 */ 121 VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr); 122 if (parm.token_addr || parm.select_mask || 123 parm.compare_mask || parm.zarch) 124 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 125 126 vcpu->run->s.regs.gprs[ry] = 0; 127 /* 128 * If the pfault handling was not established or is already 129 * canceled SC24-6084 requests to return decimal 4. 130 */ 131 if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID) 132 vcpu->run->s.regs.gprs[ry] = 4; 133 else 134 vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID; 135 136 rc = 0; 137 break; 138 default: 139 rc = -EOPNOTSUPP; 140 break; 141 } 142 143 return rc; 144 } 145 146 static int __diag_time_slice_end(struct kvm_vcpu *vcpu) 147 { 148 VCPU_EVENT(vcpu, 5, "%s", "diag time slice end"); 149 vcpu->stat.diagnose_44++; 150 kvm_vcpu_on_spin(vcpu, true); 151 return 0; 152 } 153 154 static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu) 155 { 156 struct kvm_vcpu *tcpu; 157 int tid; 158 159 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4]; 160 vcpu->stat.diagnose_9c++; 161 162 /* yield to self */ 163 if (tid == vcpu->vcpu_id) 164 goto no_yield; 165 166 /* yield to invalid */ 167 tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid); 168 if (!tcpu) 169 goto no_yield; 170 171 /* target already running */ 172 if (READ_ONCE(tcpu->cpu) >= 0) 173 goto no_yield; 174 175 if (kvm_vcpu_yield_to(tcpu) <= 0) 176 goto no_yield; 177 178 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: done", tid); 179 return 0; 180 no_yield: 181 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid); 182 vcpu->stat.diagnose_9c_ignored++; 183 return 0; 184 } 185 186 static int __diag_ipl_functions(struct kvm_vcpu *vcpu) 187 { 188 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf; 189 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff; 190 191 VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode); 192 vcpu->stat.diagnose_308++; 193 switch (subcode) { 194 case 3: 195 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR; 196 break; 197 case 4: 198 vcpu->run->s390_reset_flags = 0; 199 break; 200 default: 201 return -EOPNOTSUPP; 202 } 203 204 if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) 205 kvm_s390_vcpu_stop(vcpu); 206 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM; 207 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL; 208 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT; 209 vcpu->run->exit_reason = KVM_EXIT_S390_RESET; 210 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx", 211 vcpu->run->s390_reset_flags); 212 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags); 213 return -EREMOTE; 214 } 215 216 static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu) 217 { 218 int ret; 219 220 vcpu->stat.diagnose_500++; 221 /* No virtio-ccw notification? Get out quickly. */ 222 if (!vcpu->kvm->arch.css_support || 223 (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY)) 224 return -EOPNOTSUPP; 225 226 VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx", 227 (u32) vcpu->run->s.regs.gprs[2], 228 (u32) vcpu->run->s.regs.gprs[3], 229 vcpu->run->s.regs.gprs[4]); 230 231 /* 232 * The layout is as follows: 233 * - gpr 2 contains the subchannel id (passed as addr) 234 * - gpr 3 contains the virtqueue index (passed as datamatch) 235 * - gpr 4 contains the index on the bus (optionally) 236 */ 237 ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS, 238 vcpu->run->s.regs.gprs[2] & 0xffffffff, 239 8, &vcpu->run->s.regs.gprs[3], 240 vcpu->run->s.regs.gprs[4]); 241 242 /* 243 * Return cookie in gpr 2, but don't overwrite the register if the 244 * diagnose will be handled by userspace. 245 */ 246 if (ret != -EOPNOTSUPP) 247 vcpu->run->s.regs.gprs[2] = ret; 248 /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */ 249 return ret < 0 ? ret : 0; 250 } 251 252 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu) 253 { 254 int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff; 255 256 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 257 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 258 259 trace_kvm_s390_handle_diag(vcpu, code); 260 switch (code) { 261 case 0x10: 262 return diag_release_pages(vcpu); 263 case 0x44: 264 return __diag_time_slice_end(vcpu); 265 case 0x9c: 266 return __diag_time_slice_end_directed(vcpu); 267 case 0x258: 268 return __diag_page_ref_service(vcpu); 269 case 0x308: 270 return __diag_ipl_functions(vcpu); 271 case 0x500: 272 return __diag_virtio_hypercall(vcpu); 273 default: 274 vcpu->stat.diagnose_other++; 275 return -EOPNOTSUPP; 276 } 277 } 278