xen_ipi.c revision 1.35.6.5
1 /* $NetBSD: xen_ipi.c,v 1.35.6.5 2020/04/20 11:29:01 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 */ 37 38 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.35.6.5 2020/04/20 11:29:01 bouyer Exp $"); 39 40 #include "opt_ddb.h" 41 42 #include <sys/types.h> 43 44 #include <sys/atomic.h> 45 #include <sys/cpu.h> 46 #include <sys/mutex.h> 47 #include <sys/device.h> 48 #include <sys/xcall.h> 49 #include <sys/ipi.h> 50 #include <sys/errno.h> 51 #include <sys/systm.h> 52 53 #include <x86/fpu.h> 54 #include <machine/frame.h> 55 #include <machine/segments.h> 56 57 #include <xen/evtchn.h> 58 #include <xen/intr.h> 59 #include <xen/intrdefs.h> 60 #include <xen/hypervisor.h> 61 #include <xen/include/public/vcpu.h> 62 63 #ifdef DDB 64 extern void ddb_ipi(struct trapframe); 65 static void xen_ipi_ddb(struct cpu_info *, struct intrframe *); 66 #endif 67 68 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 69 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 70 static void xen_ipi_xcall(struct cpu_info *, struct intrframe *); 71 static void xen_ipi_hvcb(struct cpu_info *, struct intrframe *); 72 static void xen_ipi_generic(struct cpu_info *, struct intrframe *); 73 static void xen_ipi_ast(struct cpu_info *, struct intrframe *); 74 static void xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe *); 75 76 static void (*xen_ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 77 { /* In order of priority (see: xen/include/intrdefs.h */ 78 xen_ipi_halt, 79 xen_ipi_synch_fpu, 80 #ifdef DDB 81 xen_ipi_ddb, 82 #else 83 NULL, 84 #endif 85 xen_ipi_xcall, 86 xen_ipi_hvcb, 87 xen_ipi_generic, 88 xen_ipi_ast, 89 xen_ipi_kpreempt 90 }; 91 92 static int 93 xen_ipi_handler(void *arg) 94 { 95 uint32_t pending; 96 int bit; 97 struct cpu_info *ci; 98 struct intrframe *regs; 99 100 ci = curcpu(); 101 regs = arg; 102 103 KASSERT(ci == arg); 104 105 pending = atomic_swap_32(&ci->ci_ipis, 0); 106 107 KDASSERT((pending >> XEN_NIPIS) == 0); 108 while ((bit = ffs(pending)) != 0) { 109 bit--; 110 pending &= ~(1 << bit); 111 ci->ci_ipi_events[bit].ev_count++; 112 if (xen_ipifunc[bit] != NULL) { 113 (*xen_ipifunc[bit])(ci, regs); 114 } else { 115 panic("xen_ipifunc[%d] unsupported!\n", bit); 116 /* NOTREACHED */ 117 } 118 } 119 120 return 0; 121 } 122 123 /* Must be called once for every cpu that expects to send/recv ipis */ 124 void 125 xen_ipi_init(void) 126 { 127 cpuid_t vcpu; 128 evtchn_port_t evtchn; 129 struct cpu_info *ci; 130 char intr_xname[INTRDEVNAMEBUF]; 131 132 ci = curcpu(); 133 134 vcpu = ci->ci_vcpuid; 135 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 136 137 evtchn = bind_vcpu_to_evtch(vcpu); 138 ci->ci_ipi_evtchn = evtchn; 139 140 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 141 142 snprintf(intr_xname, sizeof(intr_xname), "%s ipi", 143 device_xname(ci->ci_dev)); 144 145 if (event_set_handler(evtchn, xen_ipi_handler, ci, IPL_HIGH, NULL, 146 intr_xname, true, false) != 0) { 147 panic("%s: unable to register ipi handler\n", __func__); 148 /* NOTREACHED */ 149 } 150 151 hypervisor_unmask_event(evtchn); 152 } 153 154 #ifdef DIAGNOSTIC 155 static inline bool /* helper */ 156 valid_ipimask(uint32_t ipimask) 157 { 158 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 159 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 160 XEN_IPI_HALT | XEN_IPI_KICK | XEN_IPI_AST | XEN_IPI_KPREEMPT; 161 162 if (ipimask & ~masks) { 163 return false; 164 } else { 165 return true; 166 } 167 168 } 169 #endif 170 171 int 172 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 173 { 174 evtchn_port_t evtchn; 175 176 KASSERT(ci != NULL && ci != curcpu()); 177 178 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 179 return ENOENT; 180 } 181 182 evtchn = ci->ci_ipi_evtchn; 183 184 KASSERTMSG(valid_ipimask(ipimask) == true, 185 "xen_send_ipi() called with invalid ipimask\n"); 186 187 atomic_or_32(&ci->ci_ipis, ipimask); 188 hypervisor_notify_via_evtchn(evtchn); 189 190 return 0; 191 } 192 193 void 194 xen_broadcast_ipi(uint32_t ipimask) 195 { 196 struct cpu_info *ci, *self = curcpu(); 197 CPU_INFO_ITERATOR cii; 198 199 KASSERTMSG(valid_ipimask(ipimask) == true, 200 "xen_broadcast_ipi() called with invalid ipimask\n"); 201 202 /* 203 * XXX-cherry: there's an implicit broadcast sending order 204 * which I dislike. Randomise this ? :-) 205 */ 206 207 for (CPU_INFO_FOREACH(cii, ci)) { 208 if (ci == NULL) 209 continue; 210 if (ci == self) 211 continue; 212 if (ci->ci_data.cpu_idlelwp == NULL) 213 continue; 214 if ((ci->ci_flags & CPUF_PRESENT) == 0) 215 continue; 216 if (ci->ci_flags & (CPUF_RUNNING)) { 217 if (0 != xen_send_ipi(ci, ipimask)) { 218 panic("xen_ipi of %x from %s to %s failed\n", 219 ipimask, cpu_name(curcpu()), 220 cpu_name(ci)); 221 } 222 } 223 } 224 } 225 226 /* MD wrapper for the xcall(9) callback. */ 227 228 static void 229 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 230 { 231 KASSERT(ci == curcpu()); 232 KASSERT(ci != NULL); 233 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_vcpuid, NULL)) { 234 panic("%s shutdown failed.\n", device_xname(ci->ci_dev)); 235 } 236 237 } 238 239 static void 240 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 241 { 242 KASSERT(ci != NULL); 243 KASSERT(intrf != NULL); 244 245 panic("%s: impossible", __func__); 246 } 247 248 #ifdef DDB 249 static void 250 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 251 { 252 KASSERT(ci != NULL); 253 KASSERT(intrf != NULL); 254 255 #ifdef __x86_64__ 256 ddb_ipi(intrf->if_tf); 257 #else 258 struct trapframe tf; 259 tf.tf_gs = intrf->if_gs; 260 tf.tf_fs = intrf->if_fs; 261 tf.tf_es = intrf->if_es; 262 tf.tf_ds = intrf->if_ds; 263 tf.tf_edi = intrf->if_edi; 264 tf.tf_esi = intrf->if_esi; 265 tf.tf_ebp = intrf->if_ebp; 266 tf.tf_ebx = intrf->if_ebx; 267 tf.tf_ecx = intrf->if_ecx; 268 tf.tf_eax = intrf->if_eax; 269 tf.tf_trapno = intrf->__if_trapno; 270 tf.tf_err = intrf->__if_err; 271 tf.tf_eip = intrf->if_eip; 272 tf.tf_cs = intrf->if_cs; 273 tf.tf_eflags = intrf->if_eflags; 274 tf.tf_esp = intrf->if_esp; 275 tf.tf_ss = intrf->if_ss; 276 277 ddb_ipi(tf); 278 #endif 279 } 280 #endif /* DDB */ 281 282 static void 283 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 284 { 285 KASSERT(ci != NULL); 286 KASSERT(intrf != NULL); 287 288 xc_ipi_handler(); 289 } 290 291 static void 292 xen_ipi_ast(struct cpu_info *ci, struct intrframe *intrf) 293 { 294 KASSERT(ci != NULL); 295 KASSERT(intrf != NULL); 296 297 aston(ci->ci_onproc); 298 } 299 300 static void 301 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 302 { 303 KASSERT(ci != NULL); 304 KASSERT(intrf != NULL); 305 ipi_cpu_handler(); 306 } 307 308 static void 309 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 310 { 311 KASSERT(ci != NULL); 312 KASSERT(intrf != NULL); 313 KASSERT(ci == curcpu()); 314 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 315 316 hypervisor_force_callback(); 317 } 318 319 static void 320 xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe * intrf) 321 { 322 softint_trigger(1 << SIR_PREEMPT); 323 } 324 325 #ifdef XENPV 326 void 327 xc_send_ipi(struct cpu_info *ci) 328 { 329 330 KASSERT(kpreempt_disabled()); 331 KASSERT(curcpu() != ci); 332 if (ci) { 333 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 334 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 335 } 336 } else { 337 xen_broadcast_ipi(XEN_IPI_XCALL); 338 } 339 } 340 341 void 342 cpu_ipi(struct cpu_info *ci) 343 { 344 KASSERT(kpreempt_disabled()); 345 KASSERT(curcpu() != ci); 346 if (ci) { 347 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 348 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 349 } 350 } else { 351 xen_broadcast_ipi(XEN_IPI_GENERIC); 352 } 353 } 354 #endif /* XENPV */ 355
Indexes created Tue Sep 30 20:09:53 GMT 2025