1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2008, 2013 Citrix Systems, Inc.
5 * Copyright (c) 2012 Spectra Logic Corporation
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/proc.h>
36 #include <sys/smp.h>
37 #include <sys/systm.h>
38
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41 #include <vm/vm_param.h>
42
43 #include <dev/pci/pcivar.h>
44
45 #include <machine/cpufunc.h>
46 #include <machine/cpu.h>
47 #include <machine/smp.h>
48
49 #include <x86/apicreg.h>
50
51 #include <xen/xen-os.h>
52 #include <xen/error.h>
53 #include <xen/features.h>
54 #include <xen/gnttab.h>
55 #include <xen/hypervisor.h>
56 #include <xen/hvm.h>
57 #include <xen/xen_intr.h>
58
59 #include <contrib/xen/arch-x86/cpuid.h>
60 #include <contrib/xen/hvm/params.h>
61 #include <contrib/xen/vcpu.h>
62
63 /*--------------------------- Forward Declarations ---------------------------*/
64 static void xen_hvm_cpu_init(void);
65
66 /*-------------------------------- Global Data -------------------------------*/
67 #ifdef SMP
68 struct cpu_ops xen_hvm_cpu_ops = {
69 .cpu_init = xen_hvm_cpu_init,
70 .cpu_resume = xen_hvm_cpu_init
71 };
72 #endif
73
74 static MALLOC_DEFINE(M_XENHVM, "xen_hvm", "Xen HVM PV Support");
75
76 /**
77 * If non-zero, the hypervisor has been configured to use a direct
78 * IDT event callback for interrupt injection.
79 */
80 int xen_vector_callback_enabled;
81
82 /**
83 * Signal whether the vector injected for the event channel upcall requires to
84 * be EOI'ed on the local APIC.
85 */
86 bool xen_evtchn_needs_ack;
87
88 /*------------------------------- Per-CPU Data -------------------------------*/
89 DPCPU_DECLARE(struct vcpu_info *, vcpu_info);
90
91 /*------------------------------ Sysctl tunables -----------------------------*/
92 int xen_disable_pv_disks = 0;
93 int xen_disable_pv_nics = 0;
94 TUNABLE_INT("hw.xen.disable_pv_disks", &xen_disable_pv_disks);
95 TUNABLE_INT("hw.xen.disable_pv_nics", &xen_disable_pv_nics);
96
97 /*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
98
99 uint32_t xen_cpuid_base;
100
101 static uint32_t
xen_hvm_cpuid_base(void)102 xen_hvm_cpuid_base(void)
103 {
104 uint32_t base, regs[4];
105
106 for (base = 0x40000000; base < 0x40010000; base += 0x100) {
107 do_cpuid(base, regs);
108 if (!memcmp("XenVMMXenVMM", ®s[1], 12)
109 && (regs[0] - base) >= 2)
110 return (base);
111 }
112 return (0);
113 }
114
115 static void
hypervisor_quirks(unsigned int major,unsigned int minor)116 hypervisor_quirks(unsigned int major, unsigned int minor)
117 {
118 #ifdef SMP
119 if (((major < 4) || (major == 4 && minor <= 5)) &&
120 msix_disable_migration == -1) {
121 /*
122 * Xen hypervisors prior to 4.6.0 do not properly
123 * handle updates to enabled MSI-X table entries,
124 * so disable MSI-X interrupt migration in that
125 * case.
126 */
127 if (bootverbose)
128 printf(
129 "Disabling MSI-X interrupt migration due to Xen hypervisor bug.\n"
130 "Set machdep.msix_disable_migration=0 to forcefully enable it.\n");
131 msix_disable_migration = 1;
132 }
133 #endif
134 }
135
136 static void
hypervisor_version(void)137 hypervisor_version(void)
138 {
139 uint32_t regs[4];
140 int major, minor;
141
142 do_cpuid(xen_cpuid_base + 1, regs);
143
144 major = regs[0] >> 16;
145 minor = regs[0] & 0xffff;
146 printf("XEN: Hypervisor version %d.%d detected.\n", major, minor);
147
148 hypervisor_quirks(major, minor);
149 }
150
151 /*
152 * Allocate and fill in the hypcall page.
153 */
154 int
xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)155 xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)
156 {
157 uint32_t regs[4];
158
159 /* Legacy PVH will get here without the cpuid leaf being set. */
160 if (xen_cpuid_base == 0)
161 xen_cpuid_base = xen_hvm_cpuid_base();
162 if (xen_cpuid_base == 0)
163 return (ENXIO);
164
165 if (xen_domain() && init_type == XEN_HVM_INIT_LATE) {
166 /*
167 * If the domain type is already set we can assume that the
168 * hypercall page has been populated too, so just print the
169 * version (and apply any quirks) and exit.
170 */
171 hypervisor_version();
172 return 0;
173 }
174
175 if (init_type == XEN_HVM_INIT_LATE)
176 hypervisor_version();
177
178 /*
179 * Find the hypercall pages.
180 */
181 do_cpuid(xen_cpuid_base + 2, regs);
182 if (regs[0] != 1)
183 return (EINVAL);
184
185 wrmsr(regs[1], (init_type == XEN_HVM_INIT_EARLY)
186 ? (vm_paddr_t)((uintptr_t)&hypercall_page - KERNBASE)
187 : vtophys(&hypercall_page));
188
189 return (0);
190 }
191
192 static void
xen_hvm_init_shared_info_page(void)193 xen_hvm_init_shared_info_page(void)
194 {
195 struct xen_add_to_physmap xatp;
196
197 if (xen_pv_domain()) {
198 /*
199 * Already setup in the PV case, shared_info is passed inside
200 * of the start_info struct at start of day.
201 */
202 return;
203 }
204
205 if (HYPERVISOR_shared_info == NULL) {
206 HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
207 if (HYPERVISOR_shared_info == NULL)
208 panic("Unable to allocate Xen shared info page");
209 }
210
211 xatp.domid = DOMID_SELF;
212 xatp.idx = 0;
213 xatp.space = XENMAPSPACE_shared_info;
214 xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
215 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
216 panic("HYPERVISOR_memory_op failed");
217 }
218
219 static int
set_percpu_callback(unsigned int vcpu)220 set_percpu_callback(unsigned int vcpu)
221 {
222 struct xen_hvm_evtchn_upcall_vector vec;
223 int error;
224
225 vec.vcpu = vcpu;
226 vec.vector = IDT_EVTCHN;
227 error = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &vec);
228
229 return (error != 0 ? xen_translate_error(error) : 0);
230 }
231
232 /*
233 * Tell the hypervisor how to contact us for event channel callbacks.
234 */
235 void
xen_hvm_set_callback(device_t dev)236 xen_hvm_set_callback(device_t dev)
237 {
238 struct xen_hvm_param xhp;
239 int irq;
240
241 if (xen_vector_callback_enabled)
242 return;
243
244 xhp.domid = DOMID_SELF;
245 xhp.index = HVM_PARAM_CALLBACK_IRQ;
246 if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
247 int error;
248
249 error = set_percpu_callback(0);
250 if (error == 0) {
251 xen_evtchn_needs_ack = true;
252 /* Trick toolstack to think we are enlightened */
253 xhp.value = 1;
254 } else
255 xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
256 error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
257 if (error == 0) {
258 xen_vector_callback_enabled = 1;
259 return;
260 } else if (xen_evtchn_needs_ack)
261 panic("Unable to setup fake HVM param: %d", error);
262
263 printf("Xen HVM callback vector registration failed (%d). "
264 "Falling back to emulated device interrupt\n", error);
265 }
266 xen_vector_callback_enabled = 0;
267 if (dev == NULL) {
268 /*
269 * Called from early boot or resume.
270 * xenpci will invoke us again later.
271 */
272 return;
273 }
274
275 irq = pci_get_irq(dev);
276 if (irq < 16) {
277 xhp.value = HVM_CALLBACK_GSI(irq);
278 } else {
279 u_int slot;
280 u_int pin;
281
282 slot = pci_get_slot(dev);
283 pin = pci_get_intpin(dev) - 1;
284 xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
285 }
286
287 if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
288 panic("Can't set evtchn callback");
289 }
290
291 #define XEN_MAGIC_IOPORT 0x10
292 enum {
293 XMI_MAGIC = 0x49d2,
294 XMI_UNPLUG_IDE_DISKS = 0x01,
295 XMI_UNPLUG_NICS = 0x02,
296 XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
297 };
298
299 static void
xen_hvm_disable_emulated_devices(void)300 xen_hvm_disable_emulated_devices(void)
301 {
302 u_short disable_devs = 0;
303
304 if (xen_pv_domain()) {
305 /*
306 * No emulated devices in the PV case, so no need to unplug
307 * anything.
308 */
309 if (xen_disable_pv_disks != 0 || xen_disable_pv_nics != 0)
310 printf("PV devices cannot be disabled in PV guests\n");
311 return;
312 }
313
314 if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
315 return;
316
317 if (xen_disable_pv_disks == 0) {
318 if (bootverbose)
319 printf("XEN: disabling emulated disks\n");
320 disable_devs |= XMI_UNPLUG_IDE_DISKS;
321 }
322 if (xen_disable_pv_nics == 0) {
323 if (bootverbose)
324 printf("XEN: disabling emulated nics\n");
325 disable_devs |= XMI_UNPLUG_NICS;
326 }
327
328 if (disable_devs != 0)
329 outw(XEN_MAGIC_IOPORT, disable_devs);
330 }
331
332 static void
xen_hvm_init(enum xen_hvm_init_type init_type)333 xen_hvm_init(enum xen_hvm_init_type init_type)
334 {
335 int error;
336 int i;
337
338 if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
339 return;
340
341 error = xen_hvm_init_hypercall_stubs(init_type);
342
343 switch (init_type) {
344 case XEN_HVM_INIT_LATE:
345 if (error != 0)
346 return;
347
348 /*
349 * If xen_domain_type is not set at this point
350 * it means we are inside a (PV)HVM guest, because
351 * for PVH the guest type is set much earlier
352 * (see hammer_time_xen).
353 */
354 if (!xen_domain()) {
355 xen_domain_type = XEN_HVM_DOMAIN;
356 vm_guest = VM_GUEST_XEN;
357 }
358
359 setup_xen_features();
360 #ifdef SMP
361 cpu_ops = xen_hvm_cpu_ops;
362 #endif
363 break;
364 case XEN_HVM_INIT_RESUME:
365 if (error != 0)
366 panic("Unable to init Xen hypercall stubs on resume");
367
368 /* Clear stale vcpu_info. */
369 CPU_FOREACH(i)
370 DPCPU_ID_SET(i, vcpu_info, NULL);
371 break;
372 default:
373 panic("Unsupported HVM initialization type");
374 }
375
376 xen_vector_callback_enabled = 0;
377 xen_evtchn_needs_ack = false;
378 xen_hvm_set_callback(NULL);
379
380 /*
381 * On (PV)HVM domains we need to request the hypervisor to
382 * fill the shared info page, for PVH guest the shared_info page
383 * is passed inside the start_info struct and is already set, so this
384 * functions are no-ops.
385 */
386 xen_hvm_init_shared_info_page();
387 xen_hvm_disable_emulated_devices();
388 }
389
390 void
xen_hvm_suspend(void)391 xen_hvm_suspend(void)
392 {
393 }
394
395 void
xen_hvm_resume(bool suspend_cancelled)396 xen_hvm_resume(bool suspend_cancelled)
397 {
398
399 xen_hvm_init(suspend_cancelled ?
400 XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
401
402 /* Register vcpu_info area for CPU#0. */
403 xen_hvm_cpu_init();
404 }
405
406 static void
xen_hvm_sysinit(void * arg __unused)407 xen_hvm_sysinit(void *arg __unused)
408 {
409 xen_hvm_init(XEN_HVM_INIT_LATE);
410 }
411 SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
412
413 static void
xen_hvm_cpu_init(void)414 xen_hvm_cpu_init(void)
415 {
416 uint32_t regs[4];
417 int rc;
418
419 if (!xen_domain())
420 return;
421
422 if (DPCPU_GET(vcpu_info) != NULL) {
423 /*
424 * vcpu_info is already set. We're resuming
425 * from a failed migration and our pre-suspend
426 * configuration is still valid.
427 */
428 return;
429 }
430
431 /*
432 * Set vCPU ID. If available fetch the ID from CPUID, if not just use
433 * the ACPI ID.
434 */
435 KASSERT(xen_cpuid_base != 0, ("Invalid base Xen CPUID leaf"));
436 cpuid_count(xen_cpuid_base + 4, 0, regs);
437 KASSERT((regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ||
438 !xen_pv_domain(),
439 ("Xen PV domain without vcpu_id in cpuid"));
440 PCPU_SET(vcpu_id, (regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ?
441 regs[1] : PCPU_GET(acpi_id));
442
443 if (xen_evtchn_needs_ack && !IS_BSP()) {
444 /*
445 * Setup the per-vpcu event channel upcall vector. This is only
446 * required when using the new HVMOP_set_evtchn_upcall_vector
447 * hypercall, which allows using a different vector for each
448 * vCPU. Note that FreeBSD uses the same vector for all vCPUs
449 * because it's not dynamically allocated.
450 */
451 rc = set_percpu_callback(PCPU_GET(vcpu_id));
452 if (rc != 0)
453 panic("Event channel upcall vector setup failed: %d",
454 rc);
455 }
456
457 xen_setup_vcpu_info();
458 }
459 SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
460
461 bool
xen_has_iommu_maps(void)462 xen_has_iommu_maps(void)
463 {
464 uint32_t regs[4];
465
466 KASSERT(xen_cpuid_base != 0, ("Invalid base Xen CPUID leaf"));
467 cpuid_count(xen_cpuid_base + 4, 0, regs);
468
469 return (regs[0] & XEN_HVM_CPUID_IOMMU_MAPPINGS);
470 }
471