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 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid); 162 163 if (tid == vcpu->vcpu_id) 164 return 0; 165 166 tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid); 167 if (tcpu) 168 kvm_vcpu_yield_to(tcpu); 169 return 0; 170 } 171 172 static int __diag_ipl_functions(struct kvm_vcpu *vcpu) 173 { 174 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf; 175 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff; 176 177 VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode); 178 vcpu->stat.diagnose_308++; 179 switch (subcode) { 180 case 3: 181 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR; 182 break; 183 case 4: 184 vcpu->run->s390_reset_flags = 0; 185 break; 186 default: 187 return -EOPNOTSUPP; 188 } 189 190 if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) 191 kvm_s390_vcpu_stop(vcpu); 192 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM; 193 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL; 194 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT; 195 vcpu->run->exit_reason = KVM_EXIT_S390_RESET; 196 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx", 197 vcpu->run->s390_reset_flags); 198 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags); 199 return -EREMOTE; 200 } 201 202 static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu) 203 { 204 int ret; 205 206 vcpu->stat.diagnose_500++; 207 /* No virtio-ccw notification? Get out quickly. */ 208 if (!vcpu->kvm->arch.css_support || 209 (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY)) 210 return -EOPNOTSUPP; 211 212 VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx", 213 (u32) vcpu->run->s.regs.gprs[2], 214 (u32) vcpu->run->s.regs.gprs[3], 215 vcpu->run->s.regs.gprs[4]); 216 217 /* 218 * The layout is as follows: 219 * - gpr 2 contains the subchannel id (passed as addr) 220 * - gpr 3 contains the virtqueue index (passed as datamatch) 221 * - gpr 4 contains the index on the bus (optionally) 222 */ 223 ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS, 224 vcpu->run->s.regs.gprs[2] & 0xffffffff, 225 8, &vcpu->run->s.regs.gprs[3], 226 vcpu->run->s.regs.gprs[4]); 227 228 /* 229 * Return cookie in gpr 2, but don't overwrite the register if the 230 * diagnose will be handled by userspace. 231 */ 232 if (ret != -EOPNOTSUPP) 233 vcpu->run->s.regs.gprs[2] = ret; 234 /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */ 235 return ret < 0 ? ret : 0; 236 } 237 238 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu) 239 { 240 int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff; 241 242 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 243 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 244 245 trace_kvm_s390_handle_diag(vcpu, code); 246 switch (code) { 247 case 0x10: 248 return diag_release_pages(vcpu); 249 case 0x44: 250 return __diag_time_slice_end(vcpu); 251 case 0x9c: 252 return __diag_time_slice_end_directed(vcpu); 253 case 0x258: 254 return __diag_page_ref_service(vcpu); 255 case 0x308: 256 return __diag_ipl_functions(vcpu); 257 case 0x500: 258 return __diag_virtio_hypercall(vcpu); 259 default: 260 return -EOPNOTSUPP; 261 } 262 } 263