xref: /freebsd/sys/x86/xen/hvm.c (revision 3b8f08459569bf0faa21473e5cec2491e95c9349)
1 /*
2  * Copyright (c) 2008, 2013 Citrix Systems, Inc.
3  * Copyright (c) 2012 Spectra Logic Corporation
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
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 
42 #include <dev/pci/pcivar.h>
43 
44 #include <machine/cpufunc.h>
45 #include <machine/cpu.h>
46 #include <machine/smp.h>
47 
48 #include <x86/apicreg.h>
49 
50 #include <xen/xen-os.h>
51 #include <xen/features.h>
52 #include <xen/gnttab.h>
53 #include <xen/hypervisor.h>
54 #include <xen/hvm.h>
55 #include <xen/xen_intr.h>
56 
57 #include <xen/interface/hvm/params.h>
58 #include <xen/interface/vcpu.h>
59 
60 /*--------------------------- Forward Declarations ---------------------------*/
61 #ifdef SMP
62 static driver_filter_t xen_smp_rendezvous_action;
63 static driver_filter_t xen_invltlb;
64 static driver_filter_t xen_invlpg;
65 static driver_filter_t xen_invlrng;
66 static driver_filter_t xen_invlcache;
67 #ifdef __i386__
68 static driver_filter_t xen_lazypmap;
69 #endif
70 static driver_filter_t xen_ipi_bitmap_handler;
71 static driver_filter_t xen_cpustop_handler;
72 static driver_filter_t xen_cpususpend_handler;
73 static driver_filter_t xen_cpustophard_handler;
74 static void xen_ipi_vectored(u_int vector, int dest);
75 static void xen_hvm_cpu_resume(void);
76 #endif
77 static void xen_hvm_cpu_init(void);
78 
79 /*---------------------------- Extern Declarations ---------------------------*/
80 #ifdef __i386__
81 extern void pmap_lazyfix_action(void);
82 #endif
83 #ifdef __amd64__
84 extern int pmap_pcid_enabled;
85 #endif
86 
87 /* Variables used by mp_machdep to perform the bitmap IPI */
88 extern volatile u_int cpu_ipi_pending[MAXCPU];
89 
90 /*---------------------------------- Macros ----------------------------------*/
91 #define	IPI_TO_IDX(ipi) ((ipi) - APIC_IPI_INTS)
92 
93 /*-------------------------------- Local Types -------------------------------*/
94 enum xen_hvm_init_type {
95 	XEN_HVM_INIT_COLD,
96 	XEN_HVM_INIT_CANCELLED_SUSPEND,
97 	XEN_HVM_INIT_RESUME
98 };
99 
100 struct xen_ipi_handler
101 {
102 	driver_filter_t	*filter;
103 	const char	*description;
104 };
105 
106 /*-------------------------------- Global Data -------------------------------*/
107 enum xen_domain_type xen_domain_type = XEN_NATIVE;
108 
109 #ifdef SMP
110 struct cpu_ops xen_hvm_cpu_ops = {
111 	.ipi_vectored	= lapic_ipi_vectored,
112 	.cpu_init	= xen_hvm_cpu_init,
113 	.cpu_resume	= xen_hvm_cpu_resume
114 };
115 #endif
116 
117 static MALLOC_DEFINE(M_XENHVM, "xen_hvm", "Xen HVM PV Support");
118 
119 #ifdef SMP
120 static struct xen_ipi_handler xen_ipis[] =
121 {
122 	[IPI_TO_IDX(IPI_RENDEZVOUS)]	= { xen_smp_rendezvous_action,	"r"   },
123 	[IPI_TO_IDX(IPI_INVLTLB)]	= { xen_invltlb,		"itlb"},
124 	[IPI_TO_IDX(IPI_INVLPG)]	= { xen_invlpg,			"ipg" },
125 	[IPI_TO_IDX(IPI_INVLRNG)]	= { xen_invlrng,		"irg" },
126 	[IPI_TO_IDX(IPI_INVLCACHE)]	= { xen_invlcache,		"ic"  },
127 #ifdef __i386__
128 	[IPI_TO_IDX(IPI_LAZYPMAP)]	= { xen_lazypmap,		"lp"  },
129 #endif
130 	[IPI_TO_IDX(IPI_BITMAP_VECTOR)] = { xen_ipi_bitmap_handler,	"b"   },
131 	[IPI_TO_IDX(IPI_STOP)]		= { xen_cpustop_handler,	"st"  },
132 	[IPI_TO_IDX(IPI_SUSPEND)]	= { xen_cpususpend_handler,	"sp"  },
133 	[IPI_TO_IDX(IPI_STOP_HARD)]	= { xen_cpustophard_handler,	"sth" },
134 };
135 #endif
136 
137 /**
138  * If non-zero, the hypervisor has been configured to use a direct
139  * IDT event callback for interrupt injection.
140  */
141 int xen_vector_callback_enabled;
142 
143 /*------------------------------- Per-CPU Data -------------------------------*/
144 DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
145 DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
146 #ifdef SMP
147 DPCPU_DEFINE(xen_intr_handle_t, ipi_handle[nitems(xen_ipis)]);
148 #endif
149 
150 /*------------------ Hypervisor Access Shared Memory Regions -----------------*/
151 /** Hypercall table accessed via HYPERVISOR_*_op() methods. */
152 extern char *hypercall_page;
153 shared_info_t *HYPERVISOR_shared_info;
154 start_info_t *HYPERVISOR_start_info;
155 
156 #ifdef SMP
157 /*---------------------------- XEN PV IPI Handlers ---------------------------*/
158 /*
159  * This are C clones of the ASM functions found in apic_vector.s
160  */
161 static int
162 xen_ipi_bitmap_handler(void *arg)
163 {
164 	struct trapframe *frame;
165 
166 	frame = arg;
167 	ipi_bitmap_handler(*frame);
168 	return (FILTER_HANDLED);
169 }
170 
171 static int
172 xen_smp_rendezvous_action(void *arg)
173 {
174 #ifdef COUNT_IPIS
175 	(*ipi_rendezvous_counts[PCPU_GET(cpuid)])++;
176 #endif /* COUNT_IPIS */
177 
178 	smp_rendezvous_action();
179 	return (FILTER_HANDLED);
180 }
181 
182 static int
183 xen_invltlb(void *arg)
184 {
185 
186 	invltlb_handler();
187 	return (FILTER_HANDLED);
188 }
189 
190 #ifdef __amd64__
191 static int
192 xen_invltlb_pcid(void *arg)
193 {
194 
195 	invltlb_pcid_handler();
196 	return (FILTER_HANDLED);
197 }
198 #endif
199 
200 static int
201 xen_invlpg(void *arg)
202 {
203 
204 	invlpg_handler();
205 	return (FILTER_HANDLED);
206 }
207 
208 #ifdef __amd64__
209 static int
210 xen_invlpg_pcid(void *arg)
211 {
212 
213 	invlpg_pcid_handler();
214 	return (FILTER_HANDLED);
215 }
216 #endif
217 
218 static int
219 xen_invlrng(void *arg)
220 {
221 
222 	invlrng_handler();
223 	return (FILTER_HANDLED);
224 }
225 
226 static int
227 xen_invlcache(void *arg)
228 {
229 
230 	invlcache_handler();
231 	return (FILTER_HANDLED);
232 }
233 
234 #ifdef __i386__
235 static int
236 xen_lazypmap(void *arg)
237 {
238 
239 	pmap_lazyfix_action();
240 	return (FILTER_HANDLED);
241 }
242 #endif
243 
244 static int
245 xen_cpustop_handler(void *arg)
246 {
247 
248 	cpustop_handler();
249 	return (FILTER_HANDLED);
250 }
251 
252 static int
253 xen_cpususpend_handler(void *arg)
254 {
255 
256 	cpususpend_handler();
257 	return (FILTER_HANDLED);
258 }
259 
260 static int
261 xen_cpustophard_handler(void *arg)
262 {
263 
264 	ipi_nmi_handler();
265 	return (FILTER_HANDLED);
266 }
267 
268 /* Xen PV IPI sender */
269 static void
270 xen_ipi_vectored(u_int vector, int dest)
271 {
272 	xen_intr_handle_t *ipi_handle;
273 	int ipi_idx, to_cpu, self;
274 
275 	ipi_idx = IPI_TO_IDX(vector);
276 	if (ipi_idx > nitems(xen_ipis))
277 		panic("IPI out of range");
278 
279 	switch(dest) {
280 	case APIC_IPI_DEST_SELF:
281 		ipi_handle = DPCPU_GET(ipi_handle);
282 		xen_intr_signal(ipi_handle[ipi_idx]);
283 		break;
284 	case APIC_IPI_DEST_ALL:
285 		CPU_FOREACH(to_cpu) {
286 			ipi_handle = DPCPU_ID_GET(to_cpu, ipi_handle);
287 			xen_intr_signal(ipi_handle[ipi_idx]);
288 		}
289 		break;
290 	case APIC_IPI_DEST_OTHERS:
291 		self = PCPU_GET(cpuid);
292 		CPU_FOREACH(to_cpu) {
293 			if (to_cpu != self) {
294 				ipi_handle = DPCPU_ID_GET(to_cpu, ipi_handle);
295 				xen_intr_signal(ipi_handle[ipi_idx]);
296 			}
297 		}
298 		break;
299 	default:
300 		to_cpu = apic_cpuid(dest);
301 		ipi_handle = DPCPU_ID_GET(to_cpu, ipi_handle);
302 		xen_intr_signal(ipi_handle[ipi_idx]);
303 		break;
304 	}
305 }
306 
307 /* XEN diverged cpu operations */
308 static void
309 xen_hvm_cpu_resume(void)
310 {
311 	u_int cpuid = PCPU_GET(cpuid);
312 
313 	/*
314 	 * Reset pending bitmap IPIs, because Xen doesn't preserve pending
315 	 * event channels on migration.
316 	 */
317 	cpu_ipi_pending[cpuid] = 0;
318 
319 	/* register vcpu_info area */
320 	xen_hvm_cpu_init();
321 }
322 
323 static void
324 xen_cpu_ipi_init(int cpu)
325 {
326 	xen_intr_handle_t *ipi_handle;
327 	const struct xen_ipi_handler *ipi;
328 	device_t dev;
329 	int idx, rc;
330 
331 	ipi_handle = DPCPU_ID_GET(cpu, ipi_handle);
332 	dev = pcpu_find(cpu)->pc_device;
333 	KASSERT((dev != NULL), ("NULL pcpu device_t"));
334 
335 	for (ipi = xen_ipis, idx = 0; idx < nitems(xen_ipis); ipi++, idx++) {
336 
337 		if (ipi->filter == NULL) {
338 			ipi_handle[idx] = NULL;
339 			continue;
340 		}
341 
342 		rc = xen_intr_alloc_and_bind_ipi(dev, cpu, ipi->filter,
343 		    INTR_TYPE_TTY, &ipi_handle[idx]);
344 		if (rc != 0)
345 			panic("Unable to allocate a XEN IPI port");
346 		xen_intr_describe(ipi_handle[idx], "%s", ipi->description);
347 	}
348 }
349 
350 static void
351 xen_setup_cpus(void)
352 {
353 	int i;
354 
355 	if (!xen_vector_callback_enabled)
356 		return;
357 
358 #ifdef __amd64__
359 	if (pmap_pcid_enabled) {
360 		xen_ipis[IPI_TO_IDX(IPI_INVLTLB)].filter = xen_invltlb_pcid;
361 		xen_ipis[IPI_TO_IDX(IPI_INVLPG)].filter = xen_invlpg_pcid;
362 	}
363 #endif
364 	CPU_FOREACH(i)
365 		xen_cpu_ipi_init(i);
366 
367 	/* Set the xen pv ipi ops to replace the native ones */
368 	cpu_ops.ipi_vectored = xen_ipi_vectored;
369 }
370 #endif
371 
372 /*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
373 static uint32_t
374 xen_hvm_cpuid_base(void)
375 {
376 	uint32_t base, regs[4];
377 
378 	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
379 		do_cpuid(base, regs);
380 		if (!memcmp("XenVMMXenVMM", &regs[1], 12)
381 		    && (regs[0] - base) >= 2)
382 			return (base);
383 	}
384 	return (0);
385 }
386 
387 /*
388  * Allocate and fill in the hypcall page.
389  */
390 static int
391 xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)
392 {
393 	uint32_t base, regs[4];
394 	int i;
395 
396 	if (xen_pv_domain()) {
397 		/* hypercall page is already set in the PV case */
398 		return (0);
399 	}
400 
401 	base = xen_hvm_cpuid_base();
402 	if (base == 0)
403 		return (ENXIO);
404 
405 	if (init_type == XEN_HVM_INIT_COLD) {
406 		do_cpuid(base + 1, regs);
407 		printf("XEN: Hypervisor version %d.%d detected.\n",
408 		    regs[0] >> 16, regs[0] & 0xffff);
409 	}
410 
411 	/*
412 	 * Find the hypercall pages.
413 	 */
414 	do_cpuid(base + 2, regs);
415 
416 	for (i = 0; i < regs[0]; i++)
417 		wrmsr(regs[1], vtophys(&hypercall_page + i * PAGE_SIZE) + i);
418 
419 	return (0);
420 }
421 
422 static void
423 xen_hvm_init_shared_info_page(void)
424 {
425 	struct xen_add_to_physmap xatp;
426 
427 	if (xen_pv_domain()) {
428 		/*
429 		 * Already setup in the PV case, shared_info is passed inside
430 		 * of the start_info struct at start of day.
431 		 */
432 		return;
433 	}
434 
435 	if (HYPERVISOR_shared_info == NULL) {
436 		HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
437 		if (HYPERVISOR_shared_info == NULL)
438 			panic("Unable to allocate Xen shared info page");
439 	}
440 
441 	xatp.domid = DOMID_SELF;
442 	xatp.idx = 0;
443 	xatp.space = XENMAPSPACE_shared_info;
444 	xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
445 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
446 		panic("HYPERVISOR_memory_op failed");
447 }
448 
449 /*
450  * Tell the hypervisor how to contact us for event channel callbacks.
451  */
452 void
453 xen_hvm_set_callback(device_t dev)
454 {
455 	struct xen_hvm_param xhp;
456 	int irq;
457 
458 	if (xen_vector_callback_enabled)
459 		return;
460 
461 	xhp.domid = DOMID_SELF;
462 	xhp.index = HVM_PARAM_CALLBACK_IRQ;
463 	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
464 		int error;
465 
466 		xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
467 		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
468 		if (error == 0) {
469 			xen_vector_callback_enabled = 1;
470 			return;
471 		}
472 		printf("Xen HVM callback vector registration failed (%d). "
473 		    "Falling back to emulated device interrupt\n", error);
474 	}
475 	xen_vector_callback_enabled = 0;
476 	if (dev == NULL) {
477 		/*
478 		 * Called from early boot or resume.
479 		 * xenpci will invoke us again later.
480 		 */
481 		return;
482 	}
483 
484 	irq = pci_get_irq(dev);
485 	if (irq < 16) {
486 		xhp.value = HVM_CALLBACK_GSI(irq);
487 	} else {
488 		u_int slot;
489 		u_int pin;
490 
491 		slot = pci_get_slot(dev);
492 		pin = pci_get_intpin(dev) - 1;
493 		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
494 	}
495 
496 	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
497 		panic("Can't set evtchn callback");
498 }
499 
500 #define	XEN_MAGIC_IOPORT 0x10
501 enum {
502 	XMI_MAGIC			 = 0x49d2,
503 	XMI_UNPLUG_IDE_DISKS		 = 0x01,
504 	XMI_UNPLUG_NICS			 = 0x02,
505 	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
506 };
507 
508 static void
509 xen_hvm_disable_emulated_devices(void)
510 {
511 
512 	if (xen_pv_domain()) {
513 		/*
514 		 * No emulated devices in the PV case, so no need to unplug
515 		 * anything.
516 		 */
517 		return;
518 	}
519 
520 	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
521 		return;
522 
523 	if (bootverbose)
524 		printf("XEN: Disabling emulated block and network devices\n");
525 	outw(XEN_MAGIC_IOPORT, XMI_UNPLUG_IDE_DISKS|XMI_UNPLUG_NICS);
526 }
527 
528 static void
529 xen_hvm_init(enum xen_hvm_init_type init_type)
530 {
531 	int error;
532 	int i;
533 
534 	if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
535 		return;
536 
537 	error = xen_hvm_init_hypercall_stubs(init_type);
538 
539 	switch (init_type) {
540 	case XEN_HVM_INIT_COLD:
541 		if (error != 0)
542 			return;
543 
544 		/*
545 		 * If xen_domain_type is not set at this point
546 		 * it means we are inside a (PV)HVM guest, because
547 		 * for PVH the guest type is set much earlier
548 		 * (see hammer_time_xen).
549 		 */
550 		if (!xen_domain()) {
551 			xen_domain_type = XEN_HVM_DOMAIN;
552 			vm_guest = VM_GUEST_XEN;
553 		}
554 
555 		setup_xen_features();
556 #ifdef SMP
557 		cpu_ops = xen_hvm_cpu_ops;
558 #endif
559 		break;
560 	case XEN_HVM_INIT_RESUME:
561 		if (error != 0)
562 			panic("Unable to init Xen hypercall stubs on resume");
563 
564 		/* Clear stale vcpu_info. */
565 		CPU_FOREACH(i)
566 			DPCPU_ID_SET(i, vcpu_info, NULL);
567 		break;
568 	default:
569 		panic("Unsupported HVM initialization type");
570 	}
571 
572 	xen_vector_callback_enabled = 0;
573 	xen_hvm_set_callback(NULL);
574 
575 	/*
576 	 * On (PV)HVM domains we need to request the hypervisor to
577 	 * fill the shared info page, for PVH guest the shared_info page
578 	 * is passed inside the start_info struct and is already set, so this
579 	 * functions are no-ops.
580 	 */
581 	xen_hvm_init_shared_info_page();
582 	xen_hvm_disable_emulated_devices();
583 }
584 
585 void
586 xen_hvm_suspend(void)
587 {
588 }
589 
590 void
591 xen_hvm_resume(bool suspend_cancelled)
592 {
593 
594 	xen_hvm_init(suspend_cancelled ?
595 	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
596 
597 	/* Register vcpu_info area for CPU#0. */
598 	xen_hvm_cpu_init();
599 }
600 
601 static void
602 xen_hvm_sysinit(void *arg __unused)
603 {
604 	xen_hvm_init(XEN_HVM_INIT_COLD);
605 }
606 
607 static void
608 xen_set_vcpu_id(void)
609 {
610 	struct pcpu *pc;
611 	int i;
612 
613 	if (!xen_hvm_domain())
614 		return;
615 
616 	/* Set vcpu_id to acpi_id */
617 	CPU_FOREACH(i) {
618 		pc = pcpu_find(i);
619 		pc->pc_vcpu_id = pc->pc_acpi_id;
620 		if (bootverbose)
621 			printf("XEN: CPU %u has VCPU ID %u\n",
622 			       i, pc->pc_vcpu_id);
623 	}
624 }
625 
626 static void
627 xen_hvm_cpu_init(void)
628 {
629 	struct vcpu_register_vcpu_info info;
630 	struct vcpu_info *vcpu_info;
631 	int cpu, rc;
632 
633 	if (!xen_domain())
634 		return;
635 
636 	if (DPCPU_GET(vcpu_info) != NULL) {
637 		/*
638 		 * vcpu_info is already set.  We're resuming
639 		 * from a failed migration and our pre-suspend
640 		 * configuration is still valid.
641 		 */
642 		return;
643 	}
644 
645 	vcpu_info = DPCPU_PTR(vcpu_local_info);
646 	cpu = PCPU_GET(vcpu_id);
647 	info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT;
648 	info.offset = vtophys(vcpu_info) - trunc_page(vtophys(vcpu_info));
649 
650 	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
651 	if (rc != 0)
652 		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
653 	else
654 		DPCPU_SET(vcpu_info, vcpu_info);
655 }
656 
657 SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
658 #ifdef SMP
659 /* We need to setup IPIs before APs are started */
660 SYSINIT(xen_setup_cpus, SI_SUB_SMP-1, SI_ORDER_FIRST, xen_setup_cpus, NULL);
661 #endif
662 SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
663 SYSINIT(xen_set_vcpu_id, SI_SUB_CPU, SI_ORDER_ANY, xen_set_vcpu_id, NULL);
664