1 /* $NetBSD: xen_ipi.c,v 1.23 2017/11/06 15:27:09 cherry 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 1.23 2017/11/06 15:27:09 cherry Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.23 2017/11/06 15:27:09 cherry 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 extern void ddb_ipi(struct trapframe); 63 64 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 65 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 66 static void xen_ipi_ddb(struct cpu_info *, struct intrframe *); 67 static void xen_ipi_xcall(struct cpu_info *, struct intrframe *); 68 static void xen_ipi_hvcb(struct cpu_info *, struct intrframe *); 69 static void xen_ipi_generic(struct cpu_info *, struct intrframe *); 70 71 static void (*ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 72 { /* In order of priority (see: xen/include/intrdefs.h */ 73 xen_ipi_halt, 74 xen_ipi_synch_fpu, 75 xen_ipi_ddb, 76 xen_ipi_xcall, 77 xen_ipi_hvcb, 78 xen_ipi_generic, 79 }; 80 81 static int 82 xen_ipi_handler(void *arg) 83 { 84 uint32_t pending; 85 int bit; 86 struct cpu_info *ci; 87 struct intrframe *regs; 88 89 ci = curcpu(); 90 regs = arg; 91 92 pending = atomic_swap_32(&ci->ci_ipis, 0); 93 94 KDASSERT((pending >> XEN_NIPIS) == 0); 95 while ((bit = ffs(pending)) != 0) { 96 bit--; 97 pending &= ~(1 << bit); 98 ci->ci_ipi_events[bit].ev_count++; 99 if (ipifunc[bit] != NULL) { 100 (*ipifunc[bit])(ci, regs); 101 } else { 102 panic("ipifunc[%d] unsupported!\n", bit); 103 /* NOTREACHED */ 104 } 105 } 106 107 return 0; 108 } 109 110 /* Must be called once for every cpu that expects to send/recv ipis */ 111 void 112 xen_ipi_init(void) 113 { 114 cpuid_t vcpu; 115 evtchn_port_t evtchn; 116 struct cpu_info *ci; 117 118 ci = curcpu(); 119 120 vcpu = ci->ci_cpuid; 121 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 122 123 evtchn = bind_vcpu_to_evtch(vcpu); 124 ci->ci_ipi_evtchn = evtchn; 125 126 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 127 128 if(intr_establish_xname(0, &xen_pic, evtchn, IST_LEVEL, IPL_HIGH, 129 xen_ipi_handler, ci, true, "ipi") == NULL) { 130 panic("%s: unable to register ipi handler\n", __func__); 131 /* NOTREACHED */ 132 } 133 134 hypervisor_enable_event(evtchn); 135 } 136 137 #ifdef DIAGNOSTIC 138 static inline bool /* helper */ 139 valid_ipimask(uint32_t ipimask) 140 { 141 uint32_t masks = XEN_IPI_GENERIC | XEN_IPI_HVCB | XEN_IPI_XCALL | 142 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 143 XEN_IPI_HALT | XEN_IPI_KICK; 144 145 if (ipimask & ~masks) { 146 return false; 147 } else { 148 return true; 149 } 150 151 } 152 #endif 153 154 int 155 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 156 { 157 evtchn_port_t evtchn; 158 159 KASSERT(ci != NULL || ci != curcpu()); 160 161 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 162 return ENOENT; 163 } 164 165 evtchn = ci->ci_ipi_evtchn; 166 167 KASSERTMSG(valid_ipimask(ipimask) == true, 168 "xen_send_ipi() called with invalid ipimask\n"); 169 170 atomic_or_32(&ci->ci_ipis, ipimask); 171 hypervisor_notify_via_evtchn(evtchn); 172 173 return 0; 174 } 175 176 void 177 xen_broadcast_ipi(uint32_t ipimask) 178 { 179 struct cpu_info *ci, *self = curcpu(); 180 CPU_INFO_ITERATOR cii; 181 182 KASSERTMSG(valid_ipimask(ipimask) == true, 183 "xen_broadcast_ipi() called with invalid ipimask\n"); 184 185 /* 186 * XXX-cherry: there's an implicit broadcast sending order 187 * which I dislike. Randomise this ? :-) 188 */ 189 190 for (CPU_INFO_FOREACH(cii, ci)) { 191 if (ci == NULL) 192 continue; 193 if (ci == self) 194 continue; 195 if (ci->ci_data.cpu_idlelwp == NULL) 196 continue; 197 if ((ci->ci_flags & CPUF_PRESENT) == 0) 198 continue; 199 if (ci->ci_flags & (CPUF_RUNNING)) { 200 if (0 != xen_send_ipi(ci, ipimask)) { 201 panic("xen_ipi of %x from %s to %s failed\n", 202 ipimask, cpu_name(curcpu()), 203 cpu_name(ci)); 204 } 205 } 206 } 207 } 208 209 /* MD wrapper for the xcall(9) callback. */ 210 #define PRIuCPUID "lu" /* XXX: move this somewhere more appropriate */ 211 212 static void 213 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 214 { 215 KASSERT(ci == curcpu()); 216 KASSERT(ci != NULL); 217 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 218 panic("vcpu%" PRIuCPUID "shutdown failed.\n", ci->ci_cpuid); 219 } 220 221 } 222 223 static void 224 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 225 { 226 KASSERT(ci != NULL); 227 KASSERT(intrf != NULL); 228 229 fpusave_cpu(true); 230 } 231 232 static void 233 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 234 { 235 KASSERT(ci != NULL); 236 KASSERT(intrf != NULL); 237 238 #ifdef __x86_64__ 239 ddb_ipi(intrf->if_tf); 240 #else 241 struct trapframe tf; 242 tf.tf_gs = intrf->if_gs; 243 tf.tf_fs = intrf->if_fs; 244 tf.tf_es = intrf->if_es; 245 tf.tf_ds = intrf->if_ds; 246 tf.tf_edi = intrf->if_edi; 247 tf.tf_esi = intrf->if_esi; 248 tf.tf_ebp = intrf->if_ebp; 249 tf.tf_ebx = intrf->if_ebx; 250 tf.tf_ecx = intrf->if_ecx; 251 tf.tf_eax = intrf->if_eax; 252 tf.tf_trapno = intrf->__if_trapno; 253 tf.tf_err = intrf->__if_err; 254 tf.tf_eip = intrf->if_eip; 255 tf.tf_cs = intrf->if_cs; 256 tf.tf_eflags = intrf->if_eflags; 257 tf.tf_esp = intrf->if_esp; 258 tf.tf_ss = intrf->if_ss; 259 260 ddb_ipi(tf); 261 #endif 262 } 263 264 static void 265 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 266 { 267 KASSERT(ci != NULL); 268 KASSERT(intrf != NULL); 269 270 xc_ipi_handler(); 271 } 272 273 void 274 xc_send_ipi(struct cpu_info *ci) 275 { 276 277 KASSERT(kpreempt_disabled()); 278 KASSERT(curcpu() != ci); 279 if (ci) { 280 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 281 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 282 } 283 } else { 284 xen_broadcast_ipi(XEN_IPI_XCALL); 285 } 286 } 287 288 static void 289 xen_ipi_generic(struct cpu_info *ci, struct intrframe *intrf) 290 { 291 KASSERT(ci != NULL); 292 KASSERT(intrf != NULL); 293 294 ipi_cpu_handler(); 295 } 296 297 void 298 cpu_ipi(struct cpu_info *ci) 299 { 300 KASSERT(kpreempt_disabled()); 301 KASSERT(curcpu() != ci); 302 if (ci) { 303 if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) { 304 panic("xen_send_ipi(XEN_IPI_GENERIC) failed\n"); 305 } 306 } else { 307 xen_broadcast_ipi(XEN_IPI_GENERIC); 308 } 309 } 310 311 static void 312 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 313 { 314 KASSERT(ci != NULL); 315 KASSERT(intrf != NULL); 316 KASSERT(ci == curcpu()); 317 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 318 319 hypervisor_force_callback(); 320 } 321