xen_ipi.c revision 1.40
1 /* $NetBSD: xen_ipi.c,v 1.40 2022/01/05 20:21:29 christos 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 1.40 2022/01/05 20:21:29 christos 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, ci) == NULL) { 147 panic("%s: unable to register ipi handler\n", __func__); 148 /* NOTREACHED */ 149 } 150 151 hypervisor_unmask_event(evtchn); 152 } 153 154 static inline bool /* helper */ 155 valid_ipimask(uint32_t ipimask) 156 { 157 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 158 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 159 XEN_IPI_HALT | XEN_IPI_AST | XEN_IPI_KPREEMPT; 160 161 if (ipimask & ~masks) { 162 return false; 163 } else { 164 return true; 165 } 166 167 } 168 169 int 170 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 171 { 172 evtchn_port_t evtchn; 173 174 KASSERT(ci != NULL && ci != curcpu()); 175 176 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 177 return ENOENT; 178 } 179 180 evtchn = ci->ci_ipi_evtchn; 181 182 KASSERTMSG(valid_ipimask(ipimask) == true, 183 "xen_send_ipi() called with invalid ipimask\n"); 184 185 atomic_or_32(&ci->ci_ipis, ipimask); 186 hypervisor_notify_via_evtchn(evtchn); 187 188 return 0; 189 } 190 191 void 192 xen_broadcast_ipi(uint32_t ipimask) 193 { 194 struct cpu_info *ci, *self = curcpu(); 195 CPU_INFO_ITERATOR cii; 196 197 KASSERTMSG(valid_ipimask(ipimask) == true, 198 "xen_broadcast_ipi() called with invalid ipimask\n"); 199 200 /* 201 * XXX-cherry: there's an implicit broadcast sending order 202 * which I dislike. Randomise this ? :-) 203 */ 204 205 for (CPU_INFO_FOREACH(cii, ci)) { 206 if (ci == NULL) 207 continue; 208 if (ci == self) 209 continue; 210 if (ci->ci_data.cpu_idlelwp == NULL) 211 continue; 212 if ((ci->ci_flags & CPUF_PRESENT) == 0) 213 continue; 214 if (ci->ci_flags & (CPUF_RUNNING)) { 215 if (0 != xen_send_ipi(ci, ipimask)) { 216 panic("xen_ipi of %x from %s to %s failed\n", 217 ipimask, cpu_name(curcpu()), 218 cpu_name(ci)); 219 } 220 } 221 } 222 } 223 224 /* MD wrapper for the xcall(9) callback. */ 225 226 static void 227 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 228 { 229 KASSERT(ci == curcpu()); 230 KASSERT(ci != NULL); 231 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_vcpuid, NULL)) { 232 panic("%s shutdown failed.\n", device_xname(ci->ci_dev)); 233 } 234 235 } 236 237 static void 238 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 239 { 240 KASSERT(ci != NULL); 241 KASSERT(intrf != NULL); 242 243 panic("%s: impossible", __func__); 244 } 245 246 #ifdef DDB 247 static void 248 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 249 { 250 KASSERT(ci != NULL); 251 KASSERT(intrf != NULL); 252 253 #ifdef __x86_64__ 254 ddb_ipi(intrf->if_tf); 255 #else 256 struct trapframe tf; 257 tf.tf_gs = intrf->if_gs; 258 tf.tf_fs = intrf->if_fs; 259 tf.tf_es = intrf->if_es; 260 tf.tf_ds = intrf->if_ds; 261 tf.tf_edi = intrf->if_edi; 262 tf.tf_esi = intrf->if_esi; 263 tf.tf_ebp = intrf->if_ebp; 264 tf.tf_ebx = intrf->if_ebx; 265 tf.tf_ecx = intrf->if_ecx; 266 tf.tf_eax = intrf->if_eax; 267 tf.tf_trapno = intrf->__if_trapno; 268 tf.tf_err = intrf->__if_err; 269 tf.tf_eip = intrf->if_eip; 270 tf.tf_cs = intrf->if_cs; 271 tf.tf_eflags = intrf->if_eflags; 272 tf.tf_esp = intrf->if_esp; 273 tf.tf_ss = intrf->if_ss; 274 275 ddb_ipi(tf); 276 #endif 277 } 278 #endif /* DDB */ 279 280 static void 281 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 282 { 283 KASSERT(ci != NULL); 284 KASSERT(intrf != NULL); 285 286 xc_ipi_handler(); 287 } 288 289 static void 290 xen_ipi_ast(struct cpu_info *ci, struct intrframe *intrf) 291 { 292 KASSERT(ci != NULL); 293 KASSERT(intrf != NULL); 294 295 aston(ci->ci_onproc); 296 } 297 298 static void 299 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 300 { 301 KASSERT(ci != NULL); 302 KASSERT(intrf != NULL); 303 ipi_cpu_handler(); 304 } 305 306 static void 307 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 308 { 309 KASSERT(ci != NULL); 310 KASSERT(intrf != NULL); 311 KASSERT(ci == curcpu()); 312 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 313 314 hypervisor_force_callback(); 315 } 316 317 static void 318 xen_ipi_kpreempt(struct cpu_info *ci, struct intrframe * intrf) 319 { 320 softint_trigger(1 << SIR_PREEMPT); 321 } 322 323 #ifdef XENPV 324 void 325 xc_send_ipi(struct cpu_info *ci) 326 { 327 328 KASSERT(kpreempt_disabled()); 329 KASSERT(curcpu() != ci); 330 if (ci) { 331 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 332 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 333 } 334 } else { 335 xen_broadcast_ipi(XEN_IPI_XCALL); 336 } 337 } 338 339 void 340 cpu_ipi(struct cpu_info *ci) 341 { 342 KASSERT(kpreempt_disabled()); 343 KASSERT(curcpu() != ci); 344 if (ci) { 345 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 346 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 347 } 348 } else { 349 xen_broadcast_ipi(XEN_IPI_GENERIC); 350 } 351 } 352 #endif /* XENPV */ 353
Indexes created Tue Sep 30 20:09:53 GMT 2025