1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD$");
32
33#include <sys/param.h>
34#include <sys/bus.h>
35#include <sys/kernel.h>
36#include <sys/malloc.h>
37#include <sys/proc.h>
38#include <sys/smp.h>
39#include <sys/systm.h>
40
41#include <vm/vm.h>
42#include <vm/pmap.h>
43#include <vm/vm_param.h>
44
45#include <dev/pci/pcivar.h>
46
47#include <machine/cpufunc.h>
48#include <machine/cpu.h>
49#include <machine/smp.h>
50
51#include <x86/apicreg.h>
52
53#include <xen/xen-os.h>
54#include <xen/features.h>
55#include <xen/gnttab.h>
56#include <xen/hypervisor.h>
57#include <xen/hvm.h>
58#include <xen/xen_intr.h>
59
60#include <xen/interface/arch-x86/cpuid.h>
61#include <xen/interface/hvm/params.h>
62#include <xen/interface/vcpu.h>
63
64/*--------------------------- Forward Declarations ---------------------------*/
65static void xen_hvm_cpu_init(void);
66
67/*-------------------------------- Global Data -------------------------------*/
68enum xen_domain_type xen_domain_type = XEN_NATIVE;
69
70#ifdef SMP
71struct cpu_ops xen_hvm_cpu_ops = {
72	.cpu_init	= xen_hvm_cpu_init,
73	.cpu_resume	= xen_hvm_cpu_init
74};
75#endif
76
77static MALLOC_DEFINE(M_XENHVM, "xen_hvm", "Xen HVM PV Support");
78
79/**
80 * If non-zero, the hypervisor has been configured to use a direct
81 * IDT event callback for interrupt injection.
82 */
83int xen_vector_callback_enabled;
84
85/**
86 * Start info flags. ATM this only used to store the initial domain flag for
87 * PVHv2, and it's always empty for HVM guests.
88 */
89uint32_t hvm_start_flags;
90
91/*------------------------------- Per-CPU Data -------------------------------*/
92DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
93DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
94
95/*------------------ Hypervisor Access Shared Memory Regions -----------------*/
96shared_info_t *HYPERVISOR_shared_info;
97
98/*------------------------------ Sysctl tunables -----------------------------*/
99int xen_disable_pv_disks = 0;
100int xen_disable_pv_nics = 0;
101TUNABLE_INT("hw.xen.disable_pv_disks", &xen_disable_pv_disks);
102TUNABLE_INT("hw.xen.disable_pv_nics", &xen_disable_pv_nics);
103
104/*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
105
106static uint32_t cpuid_base;
107
108static uint32_t
109xen_hvm_cpuid_base(void)
110{
111	uint32_t base, regs[4];
112
113	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
114		do_cpuid(base, regs);
115		if (!memcmp("XenVMMXenVMM", &regs[1], 12)
116		    && (regs[0] - base) >= 2)
117			return (base);
118	}
119	return (0);
120}
121
122static void
123hypervisor_quirks(unsigned int major, unsigned int minor)
124{
125#ifdef SMP
126	if (((major < 4) || (major == 4 && minor <= 5)) &&
127	    msix_disable_migration == -1) {
128		/*
129		 * Xen hypervisors prior to 4.6.0 do not properly
130		 * handle updates to enabled MSI-X table entries,
131		 * so disable MSI-X interrupt migration in that
132		 * case.
133		 */
134		if (bootverbose)
135			printf(
136"Disabling MSI-X interrupt migration due to Xen hypervisor bug.\n"
137"Set machdep.msix_disable_migration=0 to forcefully enable it.\n");
138		msix_disable_migration = 1;
139	}
140#endif
141}
142
143static void
144hypervisor_version(void)
145{
146	uint32_t regs[4];
147	int major, minor;
148
149	do_cpuid(cpuid_base + 1, regs);
150
151	major = regs[0] >> 16;
152	minor = regs[0] & 0xffff;
153	printf("XEN: Hypervisor version %d.%d detected.\n", major, minor);
154
155	hypervisor_quirks(major, minor);
156}
157
158/*
159 * Allocate and fill in the hypcall page.
160 */
161int
162xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)
163{
164	uint32_t regs[4];
165
166	/* Legacy PVH will get here without the cpuid leaf being set. */
167	if (cpuid_base == 0)
168		cpuid_base = xen_hvm_cpuid_base();
169	if (cpuid_base == 0)
170		return (ENXIO);
171
172	if (xen_domain() && init_type == XEN_HVM_INIT_LATE) {
173		/*
174		 * If the domain type is already set we can assume that the
175		 * hypercall page has been populated too, so just print the
176		 * version (and apply any quirks) and exit.
177		 */
178		hypervisor_version();
179		return 0;
180	}
181
182	if (init_type == XEN_HVM_INIT_LATE)
183		hypervisor_version();
184
185	/*
186	 * Find the hypercall pages.
187	 */
188	do_cpuid(cpuid_base + 2, regs);
189	if (regs[0] != 1)
190		return (EINVAL);
191
192	wrmsr(regs[1], (init_type == XEN_HVM_INIT_EARLY)
193	    ? ((vm_paddr_t)&hypercall_page - KERNBASE)
194	    : vtophys(&hypercall_page));
195
196	return (0);
197}
198
199static void
200xen_hvm_init_shared_info_page(void)
201{
202	struct xen_add_to_physmap xatp;
203
204	if (xen_pv_domain()) {
205		/*
206		 * Already setup in the PV case, shared_info is passed inside
207		 * of the start_info struct at start of day.
208		 */
209		return;
210	}
211
212	if (HYPERVISOR_shared_info == NULL) {
213		HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
214		if (HYPERVISOR_shared_info == NULL)
215			panic("Unable to allocate Xen shared info page");
216	}
217
218	xatp.domid = DOMID_SELF;
219	xatp.idx = 0;
220	xatp.space = XENMAPSPACE_shared_info;
221	xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
222	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
223		panic("HYPERVISOR_memory_op failed");
224}
225
226/*
227 * Tell the hypervisor how to contact us for event channel callbacks.
228 */
229void
230xen_hvm_set_callback(device_t dev)
231{
232	struct xen_hvm_param xhp;
233	int irq;
234
235	if (xen_vector_callback_enabled)
236		return;
237
238	xhp.domid = DOMID_SELF;
239	xhp.index = HVM_PARAM_CALLBACK_IRQ;
240	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
241		int error;
242
243		xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
244		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
245		if (error == 0) {
246			xen_vector_callback_enabled = 1;
247			return;
248		}
249		printf("Xen HVM callback vector registration failed (%d). "
250		    "Falling back to emulated device interrupt\n", error);
251	}
252	xen_vector_callback_enabled = 0;
253	if (dev == NULL) {
254		/*
255		 * Called from early boot or resume.
256		 * xenpci will invoke us again later.
257		 */
258		return;
259	}
260
261	irq = pci_get_irq(dev);
262	if (irq < 16) {
263		xhp.value = HVM_CALLBACK_GSI(irq);
264	} else {
265		u_int slot;
266		u_int pin;
267
268		slot = pci_get_slot(dev);
269		pin = pci_get_intpin(dev) - 1;
270		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
271	}
272
273	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
274		panic("Can't set evtchn callback");
275}
276
277#define	XEN_MAGIC_IOPORT 0x10
278enum {
279	XMI_MAGIC			 = 0x49d2,
280	XMI_UNPLUG_IDE_DISKS		 = 0x01,
281	XMI_UNPLUG_NICS			 = 0x02,
282	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
283};
284
285static void
286xen_hvm_disable_emulated_devices(void)
287{
288	u_short disable_devs = 0;
289
290	if (xen_pv_domain()) {
291		/*
292		 * No emulated devices in the PV case, so no need to unplug
293		 * anything.
294		 */
295		if (xen_disable_pv_disks != 0 || xen_disable_pv_nics != 0)
296			printf("PV devices cannot be disabled in PV guests\n");
297		return;
298	}
299
300	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
301		return;
302
303	if (xen_disable_pv_disks == 0) {
304		if (bootverbose)
305			printf("XEN: disabling emulated disks\n");
306		disable_devs |= XMI_UNPLUG_IDE_DISKS;
307	}
308	if (xen_disable_pv_nics == 0) {
309		if (bootverbose)
310			printf("XEN: disabling emulated nics\n");
311		disable_devs |= XMI_UNPLUG_NICS;
312	}
313
314	if (disable_devs != 0)
315		outw(XEN_MAGIC_IOPORT, disable_devs);
316}
317
318static void
319xen_hvm_init(enum xen_hvm_init_type init_type)
320{
321	int error;
322	int i;
323
324	if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
325		return;
326
327	error = xen_hvm_init_hypercall_stubs(init_type);
328
329	switch (init_type) {
330	case XEN_HVM_INIT_LATE:
331		if (error != 0)
332			return;
333
334		/*
335		 * If xen_domain_type is not set at this point
336		 * it means we are inside a (PV)HVM guest, because
337		 * for PVH the guest type is set much earlier
338		 * (see hammer_time_xen).
339		 */
340		if (!xen_domain()) {
341			xen_domain_type = XEN_HVM_DOMAIN;
342			vm_guest = VM_GUEST_XEN;
343		}
344
345		setup_xen_features();
346#ifdef SMP
347		cpu_ops = xen_hvm_cpu_ops;
348#endif
349		break;
350	case XEN_HVM_INIT_RESUME:
351		if (error != 0)
352			panic("Unable to init Xen hypercall stubs on resume");
353
354		/* Clear stale vcpu_info. */
355		CPU_FOREACH(i)
356			DPCPU_ID_SET(i, vcpu_info, NULL);
357		break;
358	default:
359		panic("Unsupported HVM initialization type");
360	}
361
362	xen_vector_callback_enabled = 0;
363	xen_hvm_set_callback(NULL);
364
365	/*
366	 * On (PV)HVM domains we need to request the hypervisor to
367	 * fill the shared info page, for PVH guest the shared_info page
368	 * is passed inside the start_info struct and is already set, so this
369	 * functions are no-ops.
370	 */
371	xen_hvm_init_shared_info_page();
372	xen_hvm_disable_emulated_devices();
373}
374
375void
376xen_hvm_suspend(void)
377{
378}
379
380void
381xen_hvm_resume(bool suspend_cancelled)
382{
383
384	xen_hvm_init(suspend_cancelled ?
385	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
386
387	/* Register vcpu_info area for CPU#0. */
388	xen_hvm_cpu_init();
389}
390
391static void
392xen_hvm_sysinit(void *arg __unused)
393{
394	xen_hvm_init(XEN_HVM_INIT_LATE);
395}
396SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
397
398static void
399xen_hvm_cpu_init(void)
400{
401	struct vcpu_register_vcpu_info info;
402	struct vcpu_info *vcpu_info;
403	uint32_t regs[4];
404	int cpu, rc;
405
406	if (!xen_domain())
407		return;
408
409	if (DPCPU_GET(vcpu_info) != NULL) {
410		/*
411		 * vcpu_info is already set.  We're resuming
412		 * from a failed migration and our pre-suspend
413		 * configuration is still valid.
414		 */
415		return;
416	}
417
418	/*
419	 * Set vCPU ID. If available fetch the ID from CPUID, if not just use
420	 * the ACPI ID.
421	 */
422	KASSERT(cpuid_base != 0, ("Invalid base Xen CPUID leaf"));
423	cpuid_count(cpuid_base + 4, 0, regs);
424	KASSERT((regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ||
425	    !xen_pv_domain(),
426	    ("Xen PV domain without vcpu_id in cpuid"));
427	PCPU_SET(vcpu_id, (regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ?
428	    regs[1] : PCPU_GET(acpi_id));
429
430	/*
431	 * Set the vCPU info.
432	 *
433	 * NB: the vCPU info for vCPUs < 32 can be fetched from the shared info
434	 * page, but in order to make sure the mapping code is correct always
435	 * attempt to map the vCPU info at a custom place.
436	 */
437	vcpu_info = DPCPU_PTR(vcpu_local_info);
438	cpu = PCPU_GET(vcpu_id);
439	info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT;
440	info.offset = vtophys(vcpu_info) - trunc_page(vtophys(vcpu_info));
441
442	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
443	if (rc != 0)
444		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
445	else
446		DPCPU_SET(vcpu_info, vcpu_info);
447}
448SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
449
450/* HVM/PVH start_info accessors */
451static vm_paddr_t
452hvm_get_xenstore_mfn(void)
453{
454
455	return (hvm_get_parameter(HVM_PARAM_STORE_PFN));
456}
457
458static evtchn_port_t
459hvm_get_xenstore_evtchn(void)
460{
461
462	return (hvm_get_parameter(HVM_PARAM_STORE_EVTCHN));
463}
464
465static vm_paddr_t
466hvm_get_console_mfn(void)
467{
468
469	return (hvm_get_parameter(HVM_PARAM_CONSOLE_PFN));
470}
471
472static evtchn_port_t
473hvm_get_console_evtchn(void)
474{
475
476	return (hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN));
477}
478
479static uint32_t
480hvm_get_start_flags(void)
481{
482
483	return (hvm_start_flags);
484}
485
486struct hypervisor_info hypervisor_info = {
487	.get_xenstore_mfn		= hvm_get_xenstore_mfn,
488	.get_xenstore_evtchn		= hvm_get_xenstore_evtchn,
489	.get_console_mfn		= hvm_get_console_mfn,
490	.get_console_evtchn		= hvm_get_console_evtchn,
491	.get_start_flags		= hvm_get_start_flags,
492};
493