xen_ipi.c revision 1.35.6.3
1 /* $NetBSD: xen_ipi.c,v 1.35.6.3 2020/04/16 08:46:35 bouyer Exp $ */ 2 3 /*- 4 * Copyright (c) 2011, 2019 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Cherry G. Mathew <cherry (at) zyx.in> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> /* RCS ID macro */ 33 34 /* 35 * Based on: x86/ipi.c 36 * __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.35.6.3 2020/04/16 08:46:35 bouyer Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.35.6.3 2020/04/16 08:46:35 bouyer Exp $"); 40 41 #include "opt_ddb.h" 42 43 #include <sys/types.h> 44 45 #include <sys/atomic.h> 46 #include <sys/cpu.h> 47 #include <sys/mutex.h> 48 #include <sys/device.h> 49 #include <sys/xcall.h> 50 #include <sys/ipi.h> 51 #include <sys/errno.h> 52 #include <sys/systm.h> 53 54 #include <x86/fpu.h> 55 #include <machine/frame.h> 56 #include <machine/segments.h> 57 58 #include <xen/evtchn.h> 59 #include <xen/intr.h> 60 #include <xen/intrdefs.h> 61 #include <xen/hypervisor.h> 62 #include <xen/include/public/vcpu.h> 63 64 #ifdef DDB 65 extern void ddb_ipi(struct trapframe); 66 static void xen_ipi_ddb(struct cpu_info *, struct intrframe *); 67 #endif 68 69 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 70 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 71 static void xen_ipi_xcall(struct cpu_info *, struct intrframe *); 72 static void xen_ipi_hvcb(struct cpu_info *, struct intrframe *); 73 static void xen_ipi_generic(struct cpu_info *, struct intrframe *); 74 static void xen_ipi_ast(struct cpu_info *, struct intrframe *); 75 static void xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe *); 76 77 static void (*xen_ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 78 { /* In order of priority (see: xen/include/intrdefs.h */ 79 xen_ipi_halt, 80 xen_ipi_synch_fpu, 81 #ifdef DDB 82 xen_ipi_ddb, 83 #else 84 NULL, 85 #endif 86 xen_ipi_xcall, 87 xen_ipi_hvcb, 88 xen_ipi_generic, 89 xen_ipi_ast, 90 xen_ipi_kpreempt 91 }; 92 93 static int 94 xen_ipi_handler(void *arg) 95 { 96 uint32_t pending; 97 int bit; 98 struct cpu_info *ci; 99 struct intrframe *regs; 100 101 ci = curcpu(); 102 regs = arg; 103 104 KASSERT(ci == arg); 105 106 pending = atomic_swap_32(&ci->ci_ipis, 0); 107 108 KDASSERT((pending >> XEN_NIPIS) == 0); 109 while ((bit = ffs(pending)) != 0) { 110 bit--; 111 pending &= ~(1 << bit); 112 ci->ci_ipi_events[bit].ev_count++; 113 if (xen_ipifunc[bit] != NULL) { 114 (*xen_ipifunc[bit])(ci, regs); 115 } else { 116 panic("xen_ipifunc[%d] unsupported!\n", bit); 117 /* NOTREACHED */ 118 } 119 } 120 121 return 0; 122 } 123 124 /* Must be called once for every cpu that expects to send/recv ipis */ 125 void 126 xen_ipi_init(void) 127 { 128 cpuid_t vcpu; 129 evtchn_port_t evtchn; 130 struct cpu_info *ci; 131 char intr_xname[INTRDEVNAMEBUF]; 132 133 ci = curcpu(); 134 135 vcpu = ci->ci_cpuid; 136 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 137 138 evtchn = bind_vcpu_to_evtch(vcpu); 139 ci->ci_ipi_evtchn = evtchn; 140 141 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 142 143 snprintf(intr_xname, sizeof(intr_xname), "%s ipi", 144 device_xname(ci->ci_dev)); 145 146 if (xen_intr_establish_xname(-1, &xen_pic, evtchn, IST_LEVEL, IPL_HIGH, 147 xen_ipi_handler, ci, true, intr_xname) == NULL) { 148 panic("%s: unable to register ipi handler\n", __func__); 149 /* NOTREACHED */ 150 } 151 152 hypervisor_unmask_event(evtchn); 153 } 154 155 #ifdef DIAGNOSTIC 156 static inline bool /* helper */ 157 valid_ipimask(uint32_t ipimask) 158 { 159 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 160 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 161 XEN_IPI_HALT | XEN_IPI_KICK | XEN_IPI_AST | XEN_IPI_KPREEMPT; 162 163 if (ipimask & ~masks) { 164 return false; 165 } else { 166 return true; 167 } 168 169 } 170 #endif 171 172 int 173 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 174 { 175 evtchn_port_t evtchn; 176 177 KASSERT(ci != NULL && ci != curcpu()); 178 179 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 180 return ENOENT; 181 } 182 183 evtchn = ci->ci_ipi_evtchn; 184 185 KASSERTMSG(valid_ipimask(ipimask) == true, 186 "xen_send_ipi() called with invalid ipimask\n"); 187 188 atomic_or_32(&ci->ci_ipis, ipimask); 189 hypervisor_notify_via_evtchn(evtchn); 190 191 return 0; 192 } 193 194 void 195 xen_broadcast_ipi(uint32_t ipimask) 196 { 197 struct cpu_info *ci, *self = curcpu(); 198 CPU_INFO_ITERATOR cii; 199 200 KASSERTMSG(valid_ipimask(ipimask) == true, 201 "xen_broadcast_ipi() called with invalid ipimask\n"); 202 203 /* 204 * XXX-cherry: there's an implicit broadcast sending order 205 * which I dislike. Randomise this ? :-) 206 */ 207 208 for (CPU_INFO_FOREACH(cii, ci)) { 209 if (ci == NULL) 210 continue; 211 if (ci == self) 212 continue; 213 if (ci->ci_data.cpu_idlelwp == NULL) 214 continue; 215 if ((ci->ci_flags & CPUF_PRESENT) == 0) 216 continue; 217 if (ci->ci_flags & (CPUF_RUNNING)) { 218 if (0 != xen_send_ipi(ci, ipimask)) { 219 panic("xen_ipi of %x from %s to %s failed\n", 220 ipimask, cpu_name(curcpu()), 221 cpu_name(ci)); 222 } 223 } 224 } 225 } 226 227 /* MD wrapper for the xcall(9) callback. */ 228 229 static void 230 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 231 { 232 KASSERT(ci == curcpu()); 233 KASSERT(ci != NULL); 234 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 235 panic("%s shutdown failed.\n", device_xname(ci->ci_dev)); 236 } 237 238 } 239 240 static void 241 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 242 { 243 KASSERT(ci != NULL); 244 KASSERT(intrf != NULL); 245 246 panic("%s: impossible", __func__); 247 } 248 249 #ifdef DDB 250 static void 251 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 252 { 253 KASSERT(ci != NULL); 254 KASSERT(intrf != NULL); 255 256 #ifdef __x86_64__ 257 ddb_ipi(intrf->if_tf); 258 #else 259 struct trapframe tf; 260 tf.tf_gs = intrf->if_gs; 261 tf.tf_fs = intrf->if_fs; 262 tf.tf_es = intrf->if_es; 263 tf.tf_ds = intrf->if_ds; 264 tf.tf_edi = intrf->if_edi; 265 tf.tf_esi = intrf->if_esi; 266 tf.tf_ebp = intrf->if_ebp; 267 tf.tf_ebx = intrf->if_ebx; 268 tf.tf_ecx = intrf->if_ecx; 269 tf.tf_eax = intrf->if_eax; 270 tf.tf_trapno = intrf->__if_trapno; 271 tf.tf_err = intrf->__if_err; 272 tf.tf_eip = intrf->if_eip; 273 tf.tf_cs = intrf->if_cs; 274 tf.tf_eflags = intrf->if_eflags; 275 tf.tf_esp = intrf->if_esp; 276 tf.tf_ss = intrf->if_ss; 277 278 ddb_ipi(tf); 279 #endif 280 } 281 #endif /* DDB */ 282 283 static void 284 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 285 { 286 KASSERT(ci != NULL); 287 KASSERT(intrf != NULL); 288 289 xc_ipi_handler(); 290 } 291 292 static void 293 xen_ipi_ast(struct cpu_info *ci, struct intrframe *intrf) 294 { 295 KASSERT(ci != NULL); 296 KASSERT(intrf != NULL); 297 298 aston(ci->ci_onproc); 299 } 300 301 static void 302 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 303 { 304 KASSERT(ci != NULL); 305 KASSERT(intrf != NULL); 306 ipi_cpu_handler(); 307 } 308 309 static void 310 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 311 { 312 KASSERT(ci != NULL); 313 KASSERT(intrf != NULL); 314 KASSERT(ci == curcpu()); 315 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 316 317 hypervisor_force_callback(); 318 } 319 320 static void 321 xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe * intrf) 322 { 323 softint_trigger(1 << SIR_PREEMPT); 324 } 325 326 #ifdef XENPV 327 void 328 xc_send_ipi(struct cpu_info *ci) 329 { 330 331 KASSERT(kpreempt_disabled()); 332 KASSERT(curcpu() != ci); 333 if (ci) { 334 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 335 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 336 } 337 } else { 338 xen_broadcast_ipi(XEN_IPI_XCALL); 339 } 340 } 341 342 void 343 cpu_ipi(struct cpu_info *ci) 344 { 345 KASSERT(kpreempt_disabled()); 346 KASSERT(curcpu() != ci); 347 if (ci) { 348 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 349 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 350 } 351 } else { 352 xen_broadcast_ipi(XEN_IPI_GENERIC); 353 } 354 } 355 #endif /* XENPV */ 356
Indexes created Tue Sep 30 20:09:53 GMT 2025