xen_ipi.c revision 1.17
1 /* $NetBSD: xen_ipi.c,v 1.17 2014/02/12 23:24:09 dsl 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 (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 1.17 2014/02/12 23:24:09 dsl Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.17 2014/02/12 23:24:09 dsl 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/errno.h> 49 #include <sys/systm.h> 50 51 #include <x86/fpu.h> 52 #include <machine/frame.h> 53 #include <machine/segments.h> 54 55 #include <xen/evtchn.h> 56 #include <xen/intr.h> 57 #include <xen/intrdefs.h> 58 #include <xen/hypervisor.h> 59 #include <xen/xen-public/vcpu.h> 60 61 #ifdef __x86_64__ 62 extern void ddb_ipi(struct trapframe); 63 #else 64 extern void ddb_ipi(int, struct trapframe); 65 #endif /* __x86_64__ */ 66 67 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 68 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 69 static void xen_ipi_ddb(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 73 static void (*ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 74 { /* In order of priority (see: xen/include/intrdefs.h */ 75 xen_ipi_halt, 76 xen_ipi_synch_fpu, 77 xen_ipi_ddb, 78 xen_ipi_xcall, 79 xen_ipi_hvcb 80 }; 81 82 static void 83 xen_ipi_handler(struct cpu_info *ci, struct intrframe *regs) 84 { 85 uint32_t pending; 86 int bit; 87 88 pending = atomic_swap_32(&ci->ci_ipis, 0); 89 90 KDASSERT((pending >> XEN_NIPIS) == 0); 91 while ((bit = ffs(pending)) != 0) { 92 bit--; 93 pending &= ~(1 << bit); 94 ci->ci_ipi_events[bit].ev_count++; 95 if (ipifunc[bit] != NULL) { 96 (*ipifunc[bit])(ci, regs); 97 } else { 98 panic("ipifunc[%d] unsupported!\n", bit); 99 /* NOTREACHED */ 100 } 101 } 102 } 103 104 /* Must be called once for every cpu that expects to send/recv ipis */ 105 void 106 xen_ipi_init(void) 107 { 108 cpuid_t vcpu; 109 evtchn_port_t evtchn; 110 struct cpu_info *ci; 111 112 ci = curcpu(); 113 114 vcpu = ci->ci_cpuid; 115 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 116 117 evtchn = bind_vcpu_to_evtch(vcpu); 118 ci->ci_ipi_evtchn = evtchn; 119 120 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 121 122 if (0 != event_set_handler(evtchn, (int (*)(void *))xen_ipi_handler, 123 ci, IPL_HIGH, "ipi")) { 124 panic("event_set_handler(...) KPI violation\n"); 125 /* NOTREACHED */ 126 } 127 128 hypervisor_enable_event(evtchn); 129 } 130 131 static inline bool /* helper */ 132 valid_ipimask(uint32_t ipimask) 133 { 134 uint32_t masks = XEN_IPI_HVCB | XEN_IPI_XCALL | 135 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 136 XEN_IPI_HALT | XEN_IPI_KICK; 137 138 if (ipimask & ~masks) { 139 return false; 140 } else { 141 return true; 142 } 143 144 } 145 146 int 147 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 148 { 149 evtchn_port_t evtchn; 150 151 KASSERT(ci != NULL || ci != curcpu()); 152 153 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 154 return ENOENT; 155 } 156 157 evtchn = ci->ci_ipi_evtchn; 158 159 KASSERTMSG(valid_ipimask(ipimask) == true, 160 "xen_send_ipi() called with invalid ipimask\n"); 161 162 atomic_or_32(&ci->ci_ipis, ipimask); 163 hypervisor_notify_via_evtchn(evtchn); 164 165 return 0; 166 } 167 168 void 169 xen_broadcast_ipi(uint32_t ipimask) 170 { 171 struct cpu_info *ci, *self = curcpu(); 172 CPU_INFO_ITERATOR cii; 173 174 KASSERTMSG(valid_ipimask(ipimask) == true, 175 "xen_broadcast_ipi() called with invalid ipimask\n"); 176 177 /* 178 * XXX-cherry: there's an implicit broadcast sending order 179 * which I dislike. Randomise this ? :-) 180 */ 181 182 for (CPU_INFO_FOREACH(cii, ci)) { 183 if (ci == NULL) 184 continue; 185 if (ci == self) 186 continue; 187 if (ci->ci_data.cpu_idlelwp == NULL) 188 continue; 189 if ((ci->ci_flags & CPUF_PRESENT) == 0) 190 continue; 191 if (ci->ci_flags & (CPUF_RUNNING)) { 192 if (0 != xen_send_ipi(ci, ipimask)) { 193 panic("xen_ipi of %x from %s to %s failed\n", 194 ipimask, cpu_name(curcpu()), 195 cpu_name(ci)); 196 } 197 } 198 } 199 } 200 201 /* MD wrapper for the xcall(9) callback. */ 202 #define PRIuCPUID "lu" /* XXX: move this somewhere more appropriate */ 203 204 static void 205 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 206 { 207 KASSERT(ci == curcpu()); 208 KASSERT(ci != NULL); 209 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 210 panic("vcpu%" PRIuCPUID "shutdown failed.\n", ci->ci_cpuid); 211 } 212 213 } 214 215 static void 216 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 217 { 218 KASSERT(ci != NULL); 219 KASSERT(intrf != NULL); 220 221 fpusave_cpu(true); 222 } 223 224 static void 225 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 226 { 227 KASSERT(ci != NULL); 228 KASSERT(intrf != NULL); 229 230 #ifdef __x86_64__ 231 ddb_ipi(intrf->if_tf); 232 #else 233 struct trapframe tf; 234 tf.tf_gs = intrf->if_gs; 235 tf.tf_fs = intrf->if_fs; 236 tf.tf_es = intrf->if_es; 237 tf.tf_ds = intrf->if_ds; 238 tf.tf_edi = intrf->if_edi; 239 tf.tf_esi = intrf->if_esi; 240 tf.tf_ebp = intrf->if_ebp; 241 tf.tf_ebx = intrf->if_ebx; 242 tf.tf_ecx = intrf->if_ecx; 243 tf.tf_eax = intrf->if_eax; 244 tf.tf_trapno = intrf->__if_trapno; 245 tf.tf_err = intrf->__if_err; 246 tf.tf_eip = intrf->if_eip; 247 tf.tf_cs = intrf->if_cs; 248 tf.tf_eflags = intrf->if_eflags; 249 tf.tf_esp = intrf->if_esp; 250 tf.tf_ss = intrf->if_ss; 251 252 /* XXX: does i386/Xen have vm86 support ? 253 tf.tf_vm86_es; 254 tf.tf_vm86_ds; 255 tf.tf_vm86_fs; 256 tf.tf_vm86_gs; 257 :XXX */ 258 259 ddb_ipi(SEL_KPL, tf); 260 #endif 261 } 262 263 static void 264 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 265 { 266 KASSERT(ci != NULL); 267 KASSERT(intrf != NULL); 268 269 xc_ipi_handler(); 270 } 271 272 void 273 xc_send_ipi(struct cpu_info *ci) 274 { 275 276 KASSERT(kpreempt_disabled()); 277 KASSERT(curcpu() != ci); 278 if (ci) { 279 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 280 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 281 } 282 } else { 283 xen_broadcast_ipi(XEN_IPI_XCALL); 284 } 285 } 286 287 static void 288 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 289 { 290 KASSERT(ci != NULL); 291 KASSERT(intrf != NULL); 292 KASSERT(ci == curcpu()); 293 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 294 295 hypervisor_force_callback(); 296 } 297
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