xen_ipi.c revision 1.25.2.4
1 /* $NetBSD: xen_ipi.c,v 1.25.2.4 2020/04/21 18:42:13 martin 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 1.25.2.4 2020/04/21 18:42:13 martin Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.25.2.4 2020/04/21 18:42:13 martin 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 76 static void (*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 }; 90 91 static int 92 xen_ipi_handler(void *arg) 93 { 94 uint32_t pending; 95 int bit; 96 struct cpu_info *ci; 97 struct intrframe *regs; 98 99 ci = curcpu(); 100 regs = arg; 101 102 KASSERT(ci == arg); 103 104 pending = atomic_swap_32(&ci->ci_ipis, 0); 105 106 KDASSERT((pending >> XEN_NIPIS) == 0); 107 while ((bit = ffs(pending)) != 0) { 108 bit--; 109 pending &= ~(1 << bit); 110 ci->ci_ipi_events[bit].ev_count++; 111 if (ipifunc[bit] != NULL) { 112 (*ipifunc[bit])(ci, regs); 113 } else { 114 panic("ipifunc[%d] unsupported!\n", bit); 115 /* NOTREACHED */ 116 } 117 } 118 119 return 0; 120 } 121 122 /* Must be called once for every cpu that expects to send/recv ipis */ 123 void 124 xen_ipi_init(void) 125 { 126 cpuid_t vcpu; 127 evtchn_port_t evtchn; 128 struct cpu_info *ci; 129 char intr_xname[INTRDEVNAMEBUF]; 130 131 ci = curcpu(); 132 133 vcpu = ci->ci_cpuid; 134 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 135 136 evtchn = bind_vcpu_to_evtch(vcpu); 137 ci->ci_ipi_evtchn = evtchn; 138 139 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 140 141 snprintf(intr_xname, sizeof(intr_xname), "%s ipi", 142 device_xname(ci->ci_dev)); 143 144 if (event_set_handler(evtchn, xen_ipi_handler, ci, IPL_HIGH, NULL, 145 intr_xname, true, false) != 0) { 146 panic("%s: unable to register ipi handler\n", __func__); 147 /* NOTREACHED */ 148 } 149 150 hypervisor_unmask_event(evtchn); 151 } 152 153 #ifdef DIAGNOSTIC 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_KICK | XEN_IPI_AST; 160 161 if (ipimask & ~masks) { 162 return false; 163 } else { 164 return true; 165 } 166 167 } 168 #endif 169 170 int 171 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 172 { 173 evtchn_port_t evtchn; 174 175 KASSERT(ci != NULL && ci != curcpu()); 176 177 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 178 return ENOENT; 179 } 180 181 evtchn = ci->ci_ipi_evtchn; 182 183 KASSERTMSG(valid_ipimask(ipimask) == true, 184 "xen_send_ipi() called with invalid ipimask\n"); 185 186 atomic_or_32(&ci->ci_ipis, ipimask); 187 hypervisor_notify_via_evtchn(evtchn); 188 189 return 0; 190 } 191 192 void 193 xen_broadcast_ipi(uint32_t ipimask) 194 { 195 struct cpu_info *ci, *self = curcpu(); 196 CPU_INFO_ITERATOR cii; 197 198 KASSERTMSG(valid_ipimask(ipimask) == true, 199 "xen_broadcast_ipi() called with invalid ipimask\n"); 200 201 /* 202 * XXX-cherry: there's an implicit broadcast sending order 203 * which I dislike. Randomise this ? :-) 204 */ 205 206 for (CPU_INFO_FOREACH(cii, ci)) { 207 if (ci == NULL) 208 continue; 209 if (ci == self) 210 continue; 211 if (ci->ci_data.cpu_idlelwp == NULL) 212 continue; 213 if ((ci->ci_flags & CPUF_PRESENT) == 0) 214 continue; 215 if (ci->ci_flags & (CPUF_RUNNING)) { 216 if (0 != xen_send_ipi(ci, ipimask)) { 217 panic("xen_ipi of %x from %s to %s failed\n", 218 ipimask, cpu_name(curcpu()), 219 cpu_name(ci)); 220 } 221 } 222 } 223 } 224 225 /* MD wrapper for the xcall(9) callback. */ 226 227 static void 228 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 229 { 230 KASSERT(ci == curcpu()); 231 KASSERT(ci != NULL); 232 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 233 panic("%s shutdown failed.\n", device_xname(ci->ci_dev)); 234 } 235 236 } 237 238 static void 239 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 240 { 241 KASSERT(ci != NULL); 242 KASSERT(intrf != NULL); 243 244 panic("%s: impossible", __func__); 245 } 246 247 #ifdef DDB 248 static void 249 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 250 { 251 KASSERT(ci != NULL); 252 KASSERT(intrf != NULL); 253 254 #ifdef __x86_64__ 255 ddb_ipi(intrf->if_tf); 256 #else 257 struct trapframe tf; 258 tf.tf_gs = intrf->if_gs; 259 tf.tf_fs = intrf->if_fs; 260 tf.tf_es = intrf->if_es; 261 tf.tf_ds = intrf->if_ds; 262 tf.tf_edi = intrf->if_edi; 263 tf.tf_esi = intrf->if_esi; 264 tf.tf_ebp = intrf->if_ebp; 265 tf.tf_ebx = intrf->if_ebx; 266 tf.tf_ecx = intrf->if_ecx; 267 tf.tf_eax = intrf->if_eax; 268 tf.tf_trapno = intrf->__if_trapno; 269 tf.tf_err = intrf->__if_err; 270 tf.tf_eip = intrf->if_eip; 271 tf.tf_cs = intrf->if_cs; 272 tf.tf_eflags = intrf->if_eflags; 273 tf.tf_esp = intrf->if_esp; 274 tf.tf_ss = intrf->if_ss; 275 276 ddb_ipi(tf); 277 #endif 278 } 279 #endif /* DDB */ 280 281 static void 282 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 283 { 284 KASSERT(ci != NULL); 285 KASSERT(intrf != NULL); 286 287 xc_ipi_handler(); 288 } 289 290 static void 291 xen_ipi_ast(struct cpu_info *ci, struct intrframe *intrf) 292 { 293 KASSERT(ci != NULL); 294 KASSERT(intrf != NULL); 295 296 aston(ci->ci_onproc); 297 } 298 299 void 300 xc_send_ipi(struct cpu_info *ci) 301 { 302 303 KASSERT(kpreempt_disabled()); 304 KASSERT(curcpu() != ci); 305 if (ci) { 306 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 307 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 308 } 309 } else { 310 xen_broadcast_ipi(XEN_IPI_XCALL); 311 } 312 } 313 314 static void 315 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 316 { 317 KASSERT(ci != NULL); 318 KASSERT(intrf != NULL); 319 ipi_cpu_handler(); 320 } 321 322 void 323 cpu_ipi(struct cpu_info *ci) 324 { 325 KASSERT(kpreempt_disabled()); 326 KASSERT(curcpu() != ci); 327 if (ci) { 328 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 329 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 330 } 331 } else { 332 xen_broadcast_ipi(XEN_IPI_GENERIC); 333 } 334 } 335 336 static void 337 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 338 { 339 KASSERT(ci != NULL); 340 KASSERT(intrf != NULL); 341 KASSERT(ci == curcpu()); 342 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 343 344 hypervisor_force_callback(); 345 } 346
Indexes created Tue Sep 30 20:09:53 GMT 2025