1 /* $NetBSD: xen_ipi.c,v 1.18 2014/05/19 22:47:54 rmind Exp $ */ 2 3 /*- 4 * Copyright (c) 2011 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@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 1.18 2014/05/19 22:47:54 rmind Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.18 2014/05/19 22:47:54 rmind Exp $"); 40 41 #include <sys/types.h> 42 43 #include <sys/atomic.h> 44 #include <sys/cpu.h> 45 #include <sys/mutex.h> 46 #include <sys/device.h> 47 #include <sys/xcall.h> 48 #include <sys/ipi.h> 49 #include <sys/errno.h> 50 #include <sys/systm.h> 51 52 #include <x86/fpu.h> 53 #include <machine/frame.h> 54 #include <machine/segments.h> 55 56 #include <xen/evtchn.h> 57 #include <xen/intr.h> 58 #include <xen/intrdefs.h> 59 #include <xen/hypervisor.h> 60 #include <xen/xen-public/vcpu.h> 61 62 #ifdef __x86_64__ 63 extern void ddb_ipi(struct trapframe); 64 #else 65 extern void ddb_ipi(int, struct trapframe); 66 #endif /* __x86_64__ */ 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_ddb(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 75 static void (*ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 76 { /* In order of priority (see: xen/include/intrdefs.h */ 77 xen_ipi_halt, 78 xen_ipi_synch_fpu, 79 xen_ipi_ddb, 80 xen_ipi_xcall, 81 xen_ipi_hvcb, 82 xen_ipi_generic, 83 }; 84 85 static void 86 xen_ipi_handler(struct cpu_info *ci, struct intrframe *regs) 87 { 88 uint32_t pending; 89 int bit; 90 91 pending = atomic_swap_32(&ci->ci_ipis, 0); 92 93 KDASSERT((pending >> XEN_NIPIS) == 0); 94 while ((bit = ffs(pending)) != 0) { 95 bit--; 96 pending &= ~(1 << bit); 97 ci->ci_ipi_events[bit].ev_count++; 98 if (ipifunc[bit] != NULL) { 99 (*ipifunc[bit])(ci, regs); 100 } else { 101 panic("ipifunc[%d] unsupported!\n", bit); 102 /* NOTREACHED */ 103 } 104 } 105 } 106 107 /* Must be called once for every cpu that expects to send/recv ipis */ 108 void 109 xen_ipi_init(void) 110 { 111 cpuid_t vcpu; 112 evtchn_port_t evtchn; 113 struct cpu_info *ci; 114 115 ci = curcpu(); 116 117 vcpu = ci->ci_cpuid; 118 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 119 120 evtchn = bind_vcpu_to_evtch(vcpu); 121 ci->ci_ipi_evtchn = evtchn; 122 123 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 124 125 if (0 != event_set_handler(evtchn, (int (*)(void *))xen_ipi_handler, 126 ci, IPL_HIGH, "ipi")) { 127 panic("event_set_handler(...) KPI violation\n"); 128 /* NOTREACHED */ 129 } 130 131 hypervisor_enable_event(evtchn); 132 } 133 134 static inline bool /* helper */ 135 valid_ipimask(uint32_t ipimask) 136 { 137 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 138 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 139 XEN_IPI_HALT | XEN_IPI_KICK; 140 141 if (ipimask & ~masks) { 142 return false; 143 } else { 144 return true; 145 } 146 147 } 148 149 int 150 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 151 { 152 evtchn_port_t evtchn; 153 154 KASSERT(ci != NULL || ci != curcpu()); 155 156 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 157 return ENOENT; 158 } 159 160 evtchn = ci->ci_ipi_evtchn; 161 162 KASSERTMSG(valid_ipimask(ipimask) == true, 163 "xen_send_ipi() called with invalid ipimask\n"); 164 165 atomic_or_32(&ci->ci_ipis, ipimask); 166 hypervisor_notify_via_evtchn(evtchn); 167 168 return 0; 169 } 170 171 void 172 xen_broadcast_ipi(uint32_t ipimask) 173 { 174 struct cpu_info *ci, *self = curcpu(); 175 CPU_INFO_ITERATOR cii; 176 177 KASSERTMSG(valid_ipimask(ipimask) == true, 178 "xen_broadcast_ipi() called with invalid ipimask\n"); 179 180 /* 181 * XXX-cherry: there's an implicit broadcast sending order 182 * which I dislike. Randomise this ? :-) 183 */ 184 185 for (CPU_INFO_FOREACH(cii, ci)) { 186 if (ci == NULL) 187 continue; 188 if (ci == self) 189 continue; 190 if (ci->ci_data.cpu_idlelwp == NULL) 191 continue; 192 if ((ci->ci_flags & CPUF_PRESENT) == 0) 193 continue; 194 if (ci->ci_flags & (CPUF_RUNNING)) { 195 if (0 != xen_send_ipi(ci, ipimask)) { 196 panic("xen_ipi of %x from %s to %s failed\n", 197 ipimask, cpu_name(curcpu()), 198 cpu_name(ci)); 199 } 200 } 201 } 202 } 203 204 /* MD wrapper for the xcall(9) callback. */ 205 #define PRIuCPUID "lu" /* XXX: move this somewhere more appropriate */ 206 207 static void 208 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 209 { 210 KASSERT(ci == curcpu()); 211 KASSERT(ci != NULL); 212 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 213 panic("vcpu%" PRIuCPUID "shutdown failed.\n", ci->ci_cpuid); 214 } 215 216 } 217 218 static void 219 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 220 { 221 KASSERT(ci != NULL); 222 KASSERT(intrf != NULL); 223 224 fpusave_cpu(true); 225 } 226 227 static void 228 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 229 { 230 KASSERT(ci != NULL); 231 KASSERT(intrf != NULL); 232 233 #ifdef __x86_64__ 234 ddb_ipi(intrf->if_tf); 235 #else 236 struct trapframe tf; 237 tf.tf_gs = intrf->if_gs; 238 tf.tf_fs = intrf->if_fs; 239 tf.tf_es = intrf->if_es; 240 tf.tf_ds = intrf->if_ds; 241 tf.tf_edi = intrf->if_edi; 242 tf.tf_esi = intrf->if_esi; 243 tf.tf_ebp = intrf->if_ebp; 244 tf.tf_ebx = intrf->if_ebx; 245 tf.tf_ecx = intrf->if_ecx; 246 tf.tf_eax = intrf->if_eax; 247 tf.tf_trapno = intrf->__if_trapno; 248 tf.tf_err = intrf->__if_err; 249 tf.tf_eip = intrf->if_eip; 250 tf.tf_cs = intrf->if_cs; 251 tf.tf_eflags = intrf->if_eflags; 252 tf.tf_esp = intrf->if_esp; 253 tf.tf_ss = intrf->if_ss; 254 255 /* XXX: does i386/Xen have vm86 support ? 256 tf.tf_vm86_es; 257 tf.tf_vm86_ds; 258 tf.tf_vm86_fs; 259 tf.tf_vm86_gs; 260 :XXX */ 261 262 ddb_ipi(SEL_KPL, tf); 263 #endif 264 } 265 266 static void 267 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 268 { 269 KASSERT(ci != NULL); 270 KASSERT(intrf != NULL); 271 272 xc_ipi_handler(); 273 } 274 275 void 276 xc_send_ipi(struct cpu_info *ci) 277 { 278 279 KASSERT(kpreempt_disabled()); 280 KASSERT(curcpu() != ci); 281 if (ci) { 282 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 283 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 284 } 285 } else { 286 xen_broadcast_ipi(XEN_IPI_XCALL); 287 } 288 } 289 290 static void 291 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 292 { 293 KASSERT(ci != NULL); 294 KASSERT(intrf != NULL); 295 296 ipi_cpu_handler(); 297 } 298 299 void 300 cpu_ipi(struct cpu_info *ci) 301 { 302 KASSERT(kpreempt_disabled()); 303 KASSERT(curcpu() != ci); 304 if (ci) { 305 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 306 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 307 } 308 } else { 309 xen_broadcast_ipi(XEN_IPI_GENERIC); 310 } 311 } 312 313 static void 314 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 315 { 316 KASSERT(ci != NULL); 317 KASSERT(intrf != NULL); 318 KASSERT(ci == curcpu()); 319 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 320 321 hypervisor_force_callback(); 322 } 323