xref: /freebsd/sys/x86/xen/hvm.c (revision b72ae900d4348118829fe04abdc11b620930c30f)
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/param.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/linker.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/_inttypes.h>
46 #include <machine/cpufunc.h>
47 #include <machine/cpu.h>
48 #include <machine/md_var.h>
49 #include <machine/metadata.h>
50 #include <machine/pc/bios.h>
51 #include <machine/smp.h>
52 
53 #include <x86/apicreg.h>
54 
55 #include <xen/xen-os.h>
56 #include <xen/error.h>
57 #include <xen/features.h>
58 #include <xen/gnttab.h>
59 #include <xen/hypervisor.h>
60 #include <xen/hvm.h>
61 #include <xen/xen_intr.h>
62 
63 #include <contrib/xen/arch-x86/cpuid.h>
64 #include <contrib/xen/hvm/params.h>
65 #include <contrib/xen/vcpu.h>
66 
67 /*--------------------------- Forward Declarations ---------------------------*/
68 static void xen_hvm_cpu_init(void);
69 
70 /*-------------------------------- Global Data -------------------------------*/
71 #ifdef SMP
72 struct cpu_ops xen_hvm_cpu_ops = {
73 	.cpu_init	= xen_hvm_cpu_init,
74 	.cpu_resume	= xen_hvm_cpu_init
75 };
76 #endif
77 
78 static MALLOC_DEFINE(M_XENHVM, "xen_hvm", "Xen HVM PV Support");
79 
80 /**
81  * If non-zero, the hypervisor has been configured to use a direct
82  * IDT event callback for interrupt injection.
83  */
84 int xen_vector_callback_enabled;
85 
86 /**
87  * Signal whether the vector injected for the event channel upcall requires to
88  * be EOI'ed on the local APIC.
89  */
90 bool xen_evtchn_needs_ack;
91 
92 /*------------------------------- Per-CPU Data -------------------------------*/
93 DPCPU_DECLARE(struct vcpu_info *, vcpu_info);
94 
95 /*------------------------------ Sysctl tunables -----------------------------*/
96 int xen_disable_pv_disks = 0;
97 int xen_disable_pv_nics = 0;
98 TUNABLE_INT("hw.xen.disable_pv_disks", &xen_disable_pv_disks);
99 TUNABLE_INT("hw.xen.disable_pv_nics", &xen_disable_pv_nics);
100 
101 /*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
102 
xen_emergency_print(const char * str,size_t size)103 void xen_emergency_print(const char *str, size_t size)
104 {
105 	outsb(XEN_HVM_DEBUGCONS_IOPORT, str, size);
106 }
107 
108 static void
hypervisor_quirks(unsigned int major,unsigned int minor)109 hypervisor_quirks(unsigned int major, unsigned int minor)
110 {
111 #ifdef SMP
112 	if (((major < 4) || (major == 4 && minor <= 5)) &&
113 	    msix_disable_migration == -1) {
114 		/*
115 		 * Xen hypervisors prior to 4.6.0 do not properly
116 		 * handle updates to enabled MSI-X table entries,
117 		 * so disable MSI-X interrupt migration in that
118 		 * case.
119 		 */
120 		if (bootverbose)
121 			printf(
122 "Disabling MSI-X interrupt migration due to Xen hypervisor bug.\n"
123 "Set machdep.msix_disable_migration=0 to forcefully enable it.\n");
124 		msix_disable_migration = 1;
125 	}
126 #endif
127 }
128 
129 static void
hypervisor_version(void)130 hypervisor_version(void)
131 {
132 	uint32_t regs[4];
133 	int major, minor;
134 
135 	do_cpuid(hv_base + 1, regs);
136 
137 	major = regs[0] >> 16;
138 	minor = regs[0] & 0xffff;
139 	printf("XEN: Hypervisor version %d.%d detected.\n", major, minor);
140 
141 	hypervisor_quirks(major, minor);
142 }
143 
144 /*
145  * Translate linear to physical address when still running on the bootloader
146  * created page-tables.
147  */
148 static vm_paddr_t
early_init_vtop(void * addr)149 early_init_vtop(void *addr)
150 {
151 
152 	/*
153 	 * Using a KASSERT won't print anything, as this is before console
154 	 * initialization.
155 	 */
156 	if (__predict_false((uintptr_t)addr < KERNBASE)) {
157 		xc_printf("invalid linear address: %p\n", addr);
158 		halt();
159 	}
160 
161 	return ((uintptr_t)addr - KERNBASE
162 #ifdef __amd64__
163 	    + kernphys - KERNLOAD
164 #endif
165 	    );
166 }
167 
168 static int
map_shared_info(void)169 map_shared_info(void)
170 {
171 	/*
172 	 * TODO shared info page should be mapped in an unpopulated (IOW:
173 	 * non-RAM) address.  But finding one at this point in boot is
174 	 * complicated, hence re-use a RAM address for the time being.  This
175 	 * sadly causes super-page shattering in the second stage translation
176 	 * page tables.
177 	 */
178 	static union {
179 		shared_info_t shared_info;
180 		uint8_t raw[PAGE_SIZE];
181 	} shared_page __attribute__((aligned(PAGE_SIZE)));
182 	static struct xen_add_to_physmap xatp = {
183 	    .domid = DOMID_SELF,
184 	    .space = XENMAPSPACE_shared_info,
185 	};
186 	int rc;
187 
188 	_Static_assert(sizeof(shared_page) == PAGE_SIZE,
189 	    "invalid Xen shared_info struct size");
190 
191 	if (xatp.gpfn == 0)
192 		xatp.gpfn = atop(early_init_vtop(&shared_page.shared_info));
193 
194 	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
195 	if (rc != 0) {
196 		xc_printf("cannot map shared info page: %d\n", rc);
197 		HYPERVISOR_shared_info = NULL;
198 	} else if (HYPERVISOR_shared_info == NULL)
199 		HYPERVISOR_shared_info = &shared_page.shared_info;
200 
201 	return (rc);
202 }
203 
204 static void
fixup_console(void)205 fixup_console(void)
206 {
207 	struct xen_platform_op op = {
208 		.cmd = XENPF_get_dom0_console,
209 	};
210 	xenpf_dom0_console_t *console = &op.u.dom0_console;
211 	union {
212 		struct efi_fb efi;
213 		struct vbe_fb vbe;
214 	} *fb = NULL;
215 	int size;
216 
217 	size = HYPERVISOR_platform_op(&op);
218 	if (size < 0) {
219 		xc_printf("Failed to get video console info: %d\n", size);
220 		return;
221 	}
222 
223 	switch (console->video_type) {
224 	case XEN_VGATYPE_VESA_LFB:
225 		fb = (__typeof__ (fb))preload_search_info(preload_kmdp,
226 		    MODINFO_METADATA | MODINFOMD_VBE_FB);
227 
228 		if (fb == NULL) {
229 			xc_printf("No VBE FB in kernel metadata\n");
230 			return;
231 		}
232 
233 		_Static_assert(offsetof(struct vbe_fb, fb_bpp) ==
234 		    offsetof(struct efi_fb, fb_mask_reserved) +
235 		    sizeof(fb->efi.fb_mask_reserved),
236 		    "Bad structure overlay\n");
237 		fb->vbe.fb_bpp = console->u.vesa_lfb.bits_per_pixel;
238 		/* FALLTHROUGH */
239 	case XEN_VGATYPE_EFI_LFB:
240 		if (fb == NULL) {
241 			fb = (__typeof__ (fb))preload_search_info(preload_kmdp,
242 			    MODINFO_METADATA | MODINFOMD_EFI_FB);
243 			if (fb == NULL) {
244 				xc_printf("No EFI FB in kernel metadata\n");
245 				return;
246 			}
247 		}
248 
249 		fb->efi.fb_addr = console->u.vesa_lfb.lfb_base;
250 		if (size >
251 		    offsetof(xenpf_dom0_console_t, u.vesa_lfb.ext_lfb_base))
252 			fb->efi.fb_addr |=
253 			    (uint64_t)console->u.vesa_lfb.ext_lfb_base << 32;
254 		fb->efi.fb_size = console->u.vesa_lfb.lfb_size << 16;
255 		fb->efi.fb_height = console->u.vesa_lfb.height;
256 		fb->efi.fb_width = console->u.vesa_lfb.width;
257 		fb->efi.fb_stride = (console->u.vesa_lfb.bytes_per_line << 3) /
258 		    console->u.vesa_lfb.bits_per_pixel;
259 #define FBMASK(c) \
260     ((~0u << console->u.vesa_lfb.c ## _pos) & \
261     (~0u >> (32 - console->u.vesa_lfb.c ## _pos - \
262     console->u.vesa_lfb.c ## _size)))
263 		fb->efi.fb_mask_red = FBMASK(red);
264 		fb->efi.fb_mask_green = FBMASK(green);
265 		fb->efi.fb_mask_blue = FBMASK(blue);
266 		fb->efi.fb_mask_reserved = FBMASK(rsvd);
267 #undef FBMASK
268 		break;
269 
270 	default:
271 		xc_printf("Video console type unsupported\n");
272 		return;
273 	}
274 }
275 
276 /* Early initialization when running as a Xen guest. */
277 void
xen_early_init(void)278 xen_early_init(void)
279 {
280 	uint32_t regs[4];
281 	int rc;
282 
283 	if (hv_high < hv_base + 2) {
284 		xc_printf("Invalid maximum leaves for hv_base\n");
285 		vm_guest = VM_GUEST_VM;
286 		return;
287 	}
288 
289 	/* Find the hypercall pages. */
290 	do_cpuid(hv_base + 2, regs);
291 	if (regs[0] != 1) {
292 		xc_printf("Invalid number of hypercall pages %u\n",
293 		    regs[0]);
294 		vm_guest = VM_GUEST_VM;
295 		return;
296 	}
297 
298 	wrmsr(regs[1], early_init_vtop(&hypercall_page));
299 
300 	rc = map_shared_info();
301 	if (rc != 0) {
302 		vm_guest = VM_GUEST_VM;
303 		return;
304 	}
305 
306 	if (xen_initial_domain())
307 	    /* Fixup video console information in case Xen changed the mode. */
308 	    fixup_console();
309 }
310 
311 static int
set_percpu_callback(unsigned int vcpu)312 set_percpu_callback(unsigned int vcpu)
313 {
314 	struct xen_hvm_evtchn_upcall_vector vec;
315 	int error;
316 
317 	vec.vcpu = vcpu;
318 	vec.vector = IDT_EVTCHN;
319 	error = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &vec);
320 
321 	return (error != 0 ? xen_translate_error(error) : 0);
322 }
323 
324 /*
325  * Tell the hypervisor how to contact us for event channel callbacks.
326  */
327 void
xen_hvm_set_callback(device_t dev)328 xen_hvm_set_callback(device_t dev)
329 {
330 	struct xen_hvm_param xhp;
331 	int irq;
332 
333 	if (xen_vector_callback_enabled)
334 		return;
335 
336 	xhp.domid = DOMID_SELF;
337 	xhp.index = HVM_PARAM_CALLBACK_IRQ;
338 	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
339 		int error;
340 
341 		error = set_percpu_callback(0);
342 		if (error == 0) {
343 			xen_evtchn_needs_ack = true;
344 			/* Trick toolstack to think we are enlightened */
345 			xhp.value = 1;
346 		} else
347 			xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
348 		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
349 		if (error == 0) {
350 			xen_vector_callback_enabled = 1;
351 			return;
352 		} else if (xen_evtchn_needs_ack)
353 			panic("Unable to setup fake HVM param: %d", error);
354 
355 		printf("Xen HVM callback vector registration failed (%d). "
356 		    "Falling back to emulated device interrupt\n", error);
357 	}
358 	xen_vector_callback_enabled = 0;
359 	if (dev == NULL) {
360 		/*
361 		 * Called from early boot or resume.
362 		 * xenpci will invoke us again later.
363 		 */
364 		return;
365 	}
366 
367 	irq = pci_get_irq(dev);
368 	if (irq < 16) {
369 		xhp.value = HVM_CALLBACK_GSI(irq);
370 	} else {
371 		u_int slot;
372 		u_int pin;
373 
374 		slot = pci_get_slot(dev);
375 		pin = pci_get_intpin(dev) - 1;
376 		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
377 	}
378 
379 	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
380 		panic("Can't set evtchn callback");
381 }
382 
383 #define	XEN_MAGIC_IOPORT 0x10
384 enum {
385 	XMI_MAGIC			 = 0x49d2,
386 	XMI_UNPLUG_IDE_DISKS		 = 0x01,
387 	XMI_UNPLUG_NICS			 = 0x02,
388 	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
389 };
390 
391 static void
xen_hvm_disable_emulated_devices(void)392 xen_hvm_disable_emulated_devices(void)
393 {
394 	u_short disable_devs = 0;
395 
396 	if (xen_pv_domain()) {
397 		/*
398 		 * No emulated devices in the PV case, so no need to unplug
399 		 * anything.
400 		 */
401 		if (xen_disable_pv_disks != 0 || xen_disable_pv_nics != 0)
402 			printf("PV devices cannot be disabled in PV guests\n");
403 		return;
404 	}
405 
406 	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
407 		return;
408 
409 	if (xen_disable_pv_disks == 0) {
410 		if (bootverbose)
411 			printf("XEN: disabling emulated disks\n");
412 		disable_devs |= XMI_UNPLUG_IDE_DISKS;
413 	}
414 	if (xen_disable_pv_nics == 0) {
415 		if (bootverbose)
416 			printf("XEN: disabling emulated nics\n");
417 		disable_devs |= XMI_UNPLUG_NICS;
418 	}
419 
420 	if (disable_devs != 0)
421 		outw(XEN_MAGIC_IOPORT, disable_devs);
422 }
423 
424 static void
xen_hvm_init(enum xen_hvm_init_type init_type)425 xen_hvm_init(enum xen_hvm_init_type init_type)
426 {
427 	unsigned int i;
428 
429 	if (!xen_domain() ||
430 	    init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
431 		return;
432 
433 	hypervisor_version();
434 
435 	switch (init_type) {
436 	case XEN_HVM_INIT_LATE:
437 		setup_xen_features();
438 #ifdef SMP
439 		cpu_ops = xen_hvm_cpu_ops;
440 #endif
441 		break;
442 	case XEN_HVM_INIT_RESUME:
443 		/* Clear stale vcpu_info. */
444 		CPU_FOREACH(i)
445 			DPCPU_ID_SET(i, vcpu_info, NULL);
446 
447 		if (map_shared_info() != 0)
448 			panic("cannot map Xen shared info page");
449 
450 		break;
451 	default:
452 		panic("Unsupported HVM initialization type");
453 	}
454 
455 	xen_vector_callback_enabled = 0;
456 	xen_evtchn_needs_ack = false;
457 	xen_hvm_set_callback(NULL);
458 
459 	xen_hvm_disable_emulated_devices();
460 }
461 
462 void
xen_hvm_suspend(void)463 xen_hvm_suspend(void)
464 {
465 }
466 
467 void
xen_hvm_resume(bool suspend_cancelled)468 xen_hvm_resume(bool suspend_cancelled)
469 {
470 
471 	xen_hvm_init(suspend_cancelled ?
472 	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
473 
474 	/* Register vcpu_info area for CPU#0. */
475 	xen_hvm_cpu_init();
476 }
477 
478 static void
xen_hvm_sysinit(void * arg __unused)479 xen_hvm_sysinit(void *arg __unused)
480 {
481 	xen_hvm_init(XEN_HVM_INIT_LATE);
482 }
483 SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
484 
485 static void
xen_hvm_cpu_init(void)486 xen_hvm_cpu_init(void)
487 {
488 	uint32_t regs[4];
489 	int rc;
490 
491 	if (!xen_domain())
492 		return;
493 
494 	if (DPCPU_GET(vcpu_info) != NULL) {
495 		/*
496 		 * vcpu_info is already set.  We're resuming
497 		 * from a failed migration and our pre-suspend
498 		 * configuration is still valid.
499 		 */
500 		return;
501 	}
502 
503 	/*
504 	 * Set vCPU ID. If available fetch the ID from CPUID, if not just use
505 	 * the ACPI ID.
506 	 */
507 	KASSERT(hv_base != 0, ("Invalid base Xen CPUID leaf"));
508 	cpuid_count(hv_base + 4, 0, regs);
509 	KASSERT((regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ||
510 	    !xen_pv_domain(),
511 	    ("Xen PV domain without vcpu_id in cpuid"));
512 	PCPU_SET(vcpu_id, (regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ?
513 	    regs[1] : PCPU_GET(acpi_id));
514 
515 	if (xen_evtchn_needs_ack && !IS_BSP()) {
516 		/*
517 		 * Setup the per-vpcu event channel upcall vector. This is only
518 		 * required when using the new HVMOP_set_evtchn_upcall_vector
519 		 * hypercall, which allows using a different vector for each
520 		 * vCPU. Note that FreeBSD uses the same vector for all vCPUs
521 		 * because it's not dynamically allocated.
522 		 */
523 		rc = set_percpu_callback(PCPU_GET(vcpu_id));
524 		if (rc != 0)
525 			panic("Event channel upcall vector setup failed: %d",
526 			    rc);
527 	}
528 
529 	xen_setup_vcpu_info();
530 }
531 SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
532 
533 bool
xen_has_iommu_maps(void)534 xen_has_iommu_maps(void)
535 {
536 	uint32_t regs[4];
537 
538 	KASSERT(hv_base != 0, ("Invalid base Xen CPUID leaf"));
539 	cpuid_count(hv_base + 4, 0, regs);
540 
541 	return (regs[0] & XEN_HVM_CPUID_IOMMU_MAPPINGS);
542 }
543 
544 int
xen_arch_init_physmem(device_t dev,struct rman * mem)545 xen_arch_init_physmem(device_t dev, struct rman *mem)
546 {
547 	static struct bios_smap smap[128];
548 	struct xen_memory_map memmap = {
549 		.nr_entries = nitems(smap),
550 	};
551 	unsigned int i;
552 	int error;
553 
554 	set_xen_guest_handle(memmap.buffer, smap);
555 	error = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
556 	if (error != 0)
557 		return (0);
558 
559 	/*
560 	 * Fill with UNUSABLE regions, as it's always fine to use those for
561 	 * foreign mappings, they will never be populated.
562 	 */
563 	for (i = 0; i < memmap.nr_entries; i++) {
564 		const vm_paddr_t max_phys = cpu_getmaxphyaddr();
565 		vm_paddr_t start, end;
566 
567 		if (smap[i].type != SMAP_TYPE_ACPI_ERROR)
568 			continue;
569 
570 		start = round_page(smap[i].base);
571 		/* In 32bit mode we possibly need to truncate the addresses. */
572 		end = MIN(trunc_page(smap[i].base + smap[i].length) - 1,
573 		    max_phys);
574 
575 		if (start >= end)
576 			continue;
577 
578 		if (bootverbose != 0)
579 			device_printf(dev,
580 			    "scratch mapping region @ [%016jx, %016jx]\n",
581 			    start, end);
582 
583 		error = rman_manage_region(mem, start, end);
584 		if (error != 0)
585 			device_printf(dev,
586 			    "unable to add scratch region [%016jx, %016jx]: %d\n",
587 			    start, end, error);
588 	}
589 
590 	return (0);
591 }
592