xen_ipi.c revision 1.34
1 /* $NetBSD: xen_ipi.c,v 1.34 2019/11/23 19:40:38 ad 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 1.34 2019/11/23 19:40:38 ad Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.34 2019/11/23 19:40:38 ad 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 pending = atomic_swap_32(&ci->ci_ipis, 0); 103 104 KDASSERT((pending >> XEN_NIPIS) == 0); 105 while ((bit = ffs(pending)) != 0) { 106 bit--; 107 pending &= ~(1 << bit); 108 ci->ci_ipi_events[bit].ev_count++; 109 if (ipifunc[bit] != NULL) { 110 (*ipifunc[bit])(ci, regs); 111 } else { 112 panic("ipifunc[%d] unsupported!\n", bit); 113 /* NOTREACHED */ 114 } 115 } 116 117 return 0; 118 } 119 120 /* Must be called once for every cpu that expects to send/recv ipis */ 121 void 122 xen_ipi_init(void) 123 { 124 cpuid_t vcpu; 125 evtchn_port_t evtchn; 126 struct cpu_info *ci; 127 char intr_xname[INTRDEVNAMEBUF]; 128 129 ci = curcpu(); 130 131 vcpu = ci->ci_cpuid; 132 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 133 134 evtchn = bind_vcpu_to_evtch(vcpu); 135 ci->ci_ipi_evtchn = evtchn; 136 137 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 138 139 snprintf(intr_xname, sizeof(intr_xname), "%s ipi", 140 device_xname(ci->ci_dev)); 141 142 if (xen_intr_establish_xname(-1, &xen_pic, evtchn, IST_LEVEL, IPL_HIGH, 143 xen_ipi_handler, ci, true, intr_xname) == NULL) { 144 panic("%s: unable to register ipi handler\n", __func__); 145 /* NOTREACHED */ 146 } 147 148 hypervisor_unmask_event(evtchn); 149 } 150 151 #ifdef DIAGNOSTIC 152 static inline bool /* helper */ 153 valid_ipimask(uint32_t ipimask) 154 { 155 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 156 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 157 XEN_IPI_HALT | XEN_IPI_KICK | XEN_IPI_AST; 158 159 if (ipimask & ~masks) { 160 return false; 161 } else { 162 return true; 163 } 164 165 } 166 #endif 167 168 int 169 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 170 { 171 evtchn_port_t evtchn; 172 173 KASSERT(ci != NULL && ci != curcpu()); 174 175 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 176 return ENOENT; 177 } 178 179 evtchn = ci->ci_ipi_evtchn; 180 181 KASSERTMSG(valid_ipimask(ipimask) == true, 182 "xen_send_ipi() called with invalid ipimask\n"); 183 184 atomic_or_32(&ci->ci_ipis, ipimask); 185 hypervisor_notify_via_evtchn(evtchn); 186 187 return 0; 188 } 189 190 void 191 xen_broadcast_ipi(uint32_t ipimask) 192 { 193 struct cpu_info *ci, *self = curcpu(); 194 CPU_INFO_ITERATOR cii; 195 196 KASSERTMSG(valid_ipimask(ipimask) == true, 197 "xen_broadcast_ipi() called with invalid ipimask\n"); 198 199 /* 200 * XXX-cherry: there's an implicit broadcast sending order 201 * which I dislike. Randomise this ? :-) 202 */ 203 204 for (CPU_INFO_FOREACH(cii, ci)) { 205 if (ci == NULL) 206 continue; 207 if (ci == self) 208 continue; 209 if (ci->ci_data.cpu_idlelwp == NULL) 210 continue; 211 if ((ci->ci_flags & CPUF_PRESENT) == 0) 212 continue; 213 if (ci->ci_flags & (CPUF_RUNNING)) { 214 if (0 != xen_send_ipi(ci, ipimask)) { 215 panic("xen_ipi of %x from %s to %s failed\n", 216 ipimask, cpu_name(curcpu()), 217 cpu_name(ci)); 218 } 219 } 220 } 221 } 222 223 /* MD wrapper for the xcall(9) callback. */ 224 225 static void 226 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 227 { 228 KASSERT(ci == curcpu()); 229 KASSERT(ci != NULL); 230 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 231 panic("%s shutdown failed.\n", device_xname(ci->ci_dev)); 232 } 233 234 } 235 236 static void 237 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 238 { 239 KASSERT(ci != NULL); 240 KASSERT(intrf != NULL); 241 242 panic("%s: impossible", __func__); 243 } 244 245 #ifdef DDB 246 static void 247 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 248 { 249 KASSERT(ci != NULL); 250 KASSERT(intrf != NULL); 251 252 #ifdef __x86_64__ 253 ddb_ipi(intrf->if_tf); 254 #else 255 struct trapframe tf; 256 tf.tf_gs = intrf->if_gs; 257 tf.tf_fs = intrf->if_fs; 258 tf.tf_es = intrf->if_es; 259 tf.tf_ds = intrf->if_ds; 260 tf.tf_edi = intrf->if_edi; 261 tf.tf_esi = intrf->if_esi; 262 tf.tf_ebp = intrf->if_ebp; 263 tf.tf_ebx = intrf->if_ebx; 264 tf.tf_ecx = intrf->if_ecx; 265 tf.tf_eax = intrf->if_eax; 266 tf.tf_trapno = intrf->__if_trapno; 267 tf.tf_err = intrf->__if_err; 268 tf.tf_eip = intrf->if_eip; 269 tf.tf_cs = intrf->if_cs; 270 tf.tf_eflags = intrf->if_eflags; 271 tf.tf_esp = intrf->if_esp; 272 tf.tf_ss = intrf->if_ss; 273 274 ddb_ipi(tf); 275 #endif 276 } 277 #endif /* DDB */ 278 279 static void 280 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 281 { 282 KASSERT(ci != NULL); 283 KASSERT(intrf != NULL); 284 285 xc_ipi_handler(); 286 } 287 288 static void 289 xen_ipi_ast(struct cpu_info *ci, struct intrframe *intrf) 290 { 291 KASSERT(ci != NULL); 292 KASSERT(intrf != NULL); 293 294 aston(ci->ci_data.cpu_onproc); 295 } 296 297 void 298 xc_send_ipi(struct cpu_info *ci) 299 { 300 301 KASSERT(kpreempt_disabled()); 302 KASSERT(curcpu() != ci); 303 if (ci) { 304 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 305 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 306 } 307 } else { 308 xen_broadcast_ipi(XEN_IPI_XCALL); 309 } 310 } 311 312 static void 313 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 314 { 315 KASSERT(ci != NULL); 316 KASSERT(intrf != NULL); 317 318 ipi_cpu_handler(); 319 } 320 321 void 322 cpu_ipi(struct cpu_info *ci) 323 { 324 KASSERT(kpreempt_disabled()); 325 KASSERT(curcpu() != ci); 326 if (ci) { 327 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 328 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 329 } 330 } else { 331 xen_broadcast_ipi(XEN_IPI_GENERIC); 332 } 333 } 334 335 static void 336 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 337 { 338 KASSERT(ci != NULL); 339 KASSERT(intrf != NULL); 340 KASSERT(ci == curcpu()); 341 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 342 343 hypervisor_force_callback(); 344 } 345
Indexes created Tue Sep 30 20:09:53 GMT 2025