1 /* $NetBSD: xen_ipi.c,v 1.14 2013/12/01 01:05:16 christos 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 1.14 2013/12/01 01:05:16 christos Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.14 2013/12/01 01:05:16 christos 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 #ifdef __x86_64__ 52 #include <machine/fpu.h> 53 #else 54 #include <machine/npx.h> 55 #endif /* __x86_64__ */ 56 #include <machine/frame.h> 57 #include <machine/segments.h> 58 59 #include <xen/evtchn.h> 60 #include <xen/intr.h> 61 #include <xen/intrdefs.h> 62 #include <xen/hypervisor.h> 63 #include <xen/xen-public/vcpu.h> 64 65 #ifdef __x86_64__ 66 extern void ddb_ipi(struct trapframe); 67 #else 68 extern void ddb_ipi(int, struct trapframe); 69 #endif /* __x86_64__ */ 70 71 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 72 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 73 static void xen_ipi_ddb(struct cpu_info *, struct intrframe *); 74 static void xen_ipi_xcall(struct cpu_info *, struct intrframe *); 75 static void xen_ipi_hvcb(struct cpu_info *, struct intrframe *); 76 77 static void (*ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 78 { /* In order of priority (see: xen/include/intrdefs.h */ 79 xen_ipi_halt, 80 xen_ipi_synch_fpu, 81 xen_ipi_ddb, 82 xen_ipi_xcall, 83 xen_ipi_hvcb 84 }; 85 86 static void 87 xen_ipi_handler(struct cpu_info *ci, struct intrframe *regs) 88 { 89 uint32_t pending; 90 int bit; 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 } 107 108 /* Must be called once for every cpu that expects to send/recv ipis */ 109 void 110 xen_ipi_init(void) 111 { 112 cpuid_t vcpu; 113 evtchn_port_t evtchn; 114 struct cpu_info *ci; 115 116 ci = curcpu(); 117 118 vcpu = ci->ci_cpuid; 119 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 120 121 evtchn = bind_vcpu_to_evtch(vcpu); 122 ci->ci_ipi_evtchn = evtchn; 123 124 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 125 126 if (0 != event_set_handler(evtchn, (int (*)(void *))xen_ipi_handler, 127 ci, IPL_HIGH, "ipi")) { 128 panic("event_set_handler(...) KPI violation\n"); 129 /* NOTREACHED */ 130 } 131 132 hypervisor_enable_event(evtchn); 133 } 134 135 static inline bool /* helper */ 136 valid_ipimask(uint32_t ipimask) 137 { 138 uint32_t masks = XEN_IPI_HVCB | XEN_IPI_XCALL | 139 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 140 XEN_IPI_HALT | XEN_IPI_KICK; 141 142 if (ipimask & ~masks) { 143 return false; 144 } else { 145 return true; 146 } 147 148 } 149 150 int 151 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 152 { 153 evtchn_port_t evtchn; 154 155 KASSERT(ci != NULL || ci != curcpu()); 156 157 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 158 return ENOENT; 159 } 160 161 evtchn = ci->ci_ipi_evtchn; 162 163 KASSERTMSG(valid_ipimask(ipimask) == true, 164 "xen_send_ipi() called with invalid ipimask\n"); 165 166 atomic_or_32(&ci->ci_ipis, ipimask); 167 hypervisor_notify_via_evtchn(evtchn); 168 169 return 0; 170 } 171 172 void 173 xen_broadcast_ipi(uint32_t ipimask) 174 { 175 struct cpu_info *ci, *self = curcpu(); 176 CPU_INFO_ITERATOR cii; 177 178 KASSERTMSG(valid_ipimask(ipimask) == true, 179 "xen_broadcast_ipi() called with invalid ipimask\n"); 180 181 /* 182 * XXX-cherry: there's an implicit broadcast sending order 183 * which I dislike. Randomise this ? :-) 184 */ 185 186 for (CPU_INFO_FOREACH(cii, ci)) { 187 if (ci == NULL) 188 continue; 189 if (ci == self) 190 continue; 191 if (ci->ci_data.cpu_idlelwp == NULL) 192 continue; 193 if ((ci->ci_flags & CPUF_PRESENT) == 0) 194 continue; 195 if (ci->ci_flags & (CPUF_RUNNING)) { 196 if (0 != xen_send_ipi(ci, ipimask)) { 197 panic("xen_ipi of %x from %s to %s failed\n", 198 ipimask, cpu_name(curcpu()), 199 cpu_name(ci)); 200 } 201 } 202 } 203 } 204 205 /* MD wrapper for the xcall(9) callback. */ 206 #define PRIuCPUID "lu" /* XXX: move this somewhere more appropriate */ 207 208 static void 209 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 210 { 211 KASSERT(ci == curcpu()); 212 KASSERT(ci != NULL); 213 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 214 panic("vcpu%" PRIuCPUID "shutdown failed.\n", ci->ci_cpuid); 215 } 216 217 } 218 219 static void 220 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 221 { 222 KASSERT(ci != NULL); 223 KASSERT(intrf != NULL); 224 225 #ifdef __x86_64__ 226 fpusave_cpu(true); 227 #else 228 npxsave_cpu(true); 229 #endif /* __x86_64__ */ 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 /* XXX: does i386/Xen have vm86 support ? 261 tf.tf_vm86_es; 262 tf.tf_vm86_ds; 263 tf.tf_vm86_fs; 264 tf.tf_vm86_gs; 265 :XXX */ 266 267 ddb_ipi(SEL_KPL, tf); 268 #endif 269 } 270 271 static void 272 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 273 { 274 KASSERT(ci != NULL); 275 KASSERT(intrf != NULL); 276 277 xc_ipi_handler(); 278 } 279 280 void 281 xc_send_ipi(struct cpu_info *ci) 282 { 283 284 KASSERT(kpreempt_disabled()); 285 KASSERT(curcpu() != ci); 286 if (ci) { 287 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 288 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 289 } 290 } else { 291 xen_broadcast_ipi(XEN_IPI_XCALL); 292 } 293 } 294 295 static void 296 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 297 { 298 KASSERT(ci != NULL); 299 KASSERT(intrf != NULL); 300 KASSERT(ci == curcpu()); 301 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 302 303 hypervisor_force_callback(); 304 } 305