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 ---------------------------*/
61static void xen_hvm_cpu_init(void);
62
63/*-------------------------------- Local Types -------------------------------*/
64enum xen_hvm_init_type {
65	XEN_HVM_INIT_COLD,
66	XEN_HVM_INIT_CANCELLED_SUSPEND,
67	XEN_HVM_INIT_RESUME
68};
69
70/*-------------------------------- Global Data -------------------------------*/
71enum xen_domain_type xen_domain_type = XEN_NATIVE;
72
73#ifdef SMP
74struct cpu_ops xen_hvm_cpu_ops = {
75	.cpu_init	= xen_hvm_cpu_init,
76	.cpu_resume	= xen_hvm_cpu_init
77};
78#endif
79
80static MALLOC_DEFINE(M_XENHVM, "xen_hvm", "Xen HVM PV Support");
81
82/**
83 * If non-zero, the hypervisor has been configured to use a direct
84 * IDT event callback for interrupt injection.
85 */
86int xen_vector_callback_enabled;
87
88/*------------------------------- Per-CPU Data -------------------------------*/
89DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
90DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
91
92/*------------------ Hypervisor Access Shared Memory Regions -----------------*/
93shared_info_t *HYPERVISOR_shared_info;
94start_info_t *HYPERVISOR_start_info;
95
96
97/*------------------------------ Sysctl tunables -----------------------------*/
98int xen_disable_pv_disks = 0;
99int xen_disable_pv_nics = 0;
100TUNABLE_INT("hw.xen.disable_pv_disks", &xen_disable_pv_disks);
101TUNABLE_INT("hw.xen.disable_pv_nics", &xen_disable_pv_nics);
102
103/*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
104static uint32_t
105xen_hvm_cpuid_base(void)
106{
107	uint32_t base, regs[4];
108
109	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
110		do_cpuid(base, regs);
111		if (!memcmp("XenVMMXenVMM", &regs[1], 12)
112		    && (regs[0] - base) >= 2)
113			return (base);
114	}
115	return (0);
116}
117
118/*
119 * Allocate and fill in the hypcall page.
120 */
121static int
122xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)
123{
124	uint32_t base, regs[4];
125	int i;
126
127	if (xen_pv_domain()) {
128		/* hypercall page is already set in the PV case */
129		return (0);
130	}
131
132	base = xen_hvm_cpuid_base();
133	if (base == 0)
134		return (ENXIO);
135
136	if (init_type == XEN_HVM_INIT_COLD) {
137		int major, minor;
138
139		do_cpuid(base + 1, regs);
140
141		major = regs[0] >> 16;
142		minor = regs[0] & 0xffff;
143		printf("XEN: Hypervisor version %d.%d detected.\n", major,
144			minor);
145
146#ifdef SMP
147		if (((major < 4) || (major == 4 && minor <= 5)) &&
148		    msix_disable_migration == -1) {
149			/*
150			 * Xen hypervisors prior to 4.6.0 do not properly
151			 * handle updates to enabled MSI-X table entries,
152			 * so disable MSI-X interrupt migration in that
153			 * case.
154			 */
155			if (bootverbose)
156				printf(
157"Disabling MSI-X interrupt migration due to Xen hypervisor bug.\n"
158"Set machdep.msix_disable_migration=0 to forcefully enable it.\n");
159			msix_disable_migration = 1;
160		}
161#endif
162	}
163
164	/*
165	 * Find the hypercall pages.
166	 */
167	do_cpuid(base + 2, regs);
168
169	for (i = 0; i < regs[0]; i++)
170		wrmsr(regs[1], vtophys(&hypercall_page + i * PAGE_SIZE) + i);
171
172	return (0);
173}
174
175static void
176xen_hvm_init_shared_info_page(void)
177{
178	struct xen_add_to_physmap xatp;
179
180	if (xen_pv_domain()) {
181		/*
182		 * Already setup in the PV case, shared_info is passed inside
183		 * of the start_info struct at start of day.
184		 */
185		return;
186	}
187
188	if (HYPERVISOR_shared_info == NULL) {
189		HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
190		if (HYPERVISOR_shared_info == NULL)
191			panic("Unable to allocate Xen shared info page");
192	}
193
194	xatp.domid = DOMID_SELF;
195	xatp.idx = 0;
196	xatp.space = XENMAPSPACE_shared_info;
197	xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
198	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
199		panic("HYPERVISOR_memory_op failed");
200}
201
202/*
203 * Tell the hypervisor how to contact us for event channel callbacks.
204 */
205void
206xen_hvm_set_callback(device_t dev)
207{
208	struct xen_hvm_param xhp;
209	int irq;
210
211	if (xen_vector_callback_enabled)
212		return;
213
214	xhp.domid = DOMID_SELF;
215	xhp.index = HVM_PARAM_CALLBACK_IRQ;
216	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
217		int error;
218
219		xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
220		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
221		if (error == 0) {
222			xen_vector_callback_enabled = 1;
223			return;
224		}
225		printf("Xen HVM callback vector registration failed (%d). "
226		    "Falling back to emulated device interrupt\n", error);
227	}
228	xen_vector_callback_enabled = 0;
229	if (dev == NULL) {
230		/*
231		 * Called from early boot or resume.
232		 * xenpci will invoke us again later.
233		 */
234		return;
235	}
236
237	irq = pci_get_irq(dev);
238	if (irq < 16) {
239		xhp.value = HVM_CALLBACK_GSI(irq);
240	} else {
241		u_int slot;
242		u_int pin;
243
244		slot = pci_get_slot(dev);
245		pin = pci_get_intpin(dev) - 1;
246		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
247	}
248
249	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
250		panic("Can't set evtchn callback");
251}
252
253#define	XEN_MAGIC_IOPORT 0x10
254enum {
255	XMI_MAGIC			 = 0x49d2,
256	XMI_UNPLUG_IDE_DISKS		 = 0x01,
257	XMI_UNPLUG_NICS			 = 0x02,
258	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
259};
260
261static void
262xen_hvm_disable_emulated_devices(void)
263{
264	u_short disable_devs = 0;
265
266	if (xen_pv_domain()) {
267		/*
268		 * No emulated devices in the PV case, so no need to unplug
269		 * anything.
270		 */
271		if (xen_disable_pv_disks != 0 || xen_disable_pv_nics != 0)
272			printf("PV devices cannot be disabled in PV guests\n");
273		return;
274	}
275
276	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
277		return;
278
279	if (xen_disable_pv_disks == 0) {
280		if (bootverbose)
281			printf("XEN: disabling emulated disks\n");
282		disable_devs |= XMI_UNPLUG_IDE_DISKS;
283	}
284	if (xen_disable_pv_nics == 0) {
285		if (bootverbose)
286			printf("XEN: disabling emulated nics\n");
287		disable_devs |= XMI_UNPLUG_NICS;
288	}
289
290	if (disable_devs != 0)
291		outw(XEN_MAGIC_IOPORT, disable_devs);
292}
293
294static void
295xen_hvm_init(enum xen_hvm_init_type init_type)
296{
297	int error;
298	int i;
299
300	if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
301		return;
302
303	error = xen_hvm_init_hypercall_stubs(init_type);
304
305	switch (init_type) {
306	case XEN_HVM_INIT_COLD:
307		if (error != 0)
308			return;
309
310		/*
311		 * If xen_domain_type is not set at this point
312		 * it means we are inside a (PV)HVM guest, because
313		 * for PVH the guest type is set much earlier
314		 * (see hammer_time_xen).
315		 */
316		if (!xen_domain()) {
317			xen_domain_type = XEN_HVM_DOMAIN;
318			vm_guest = VM_GUEST_XEN;
319		}
320
321		setup_xen_features();
322#ifdef SMP
323		cpu_ops = xen_hvm_cpu_ops;
324#endif
325		break;
326	case XEN_HVM_INIT_RESUME:
327		if (error != 0)
328			panic("Unable to init Xen hypercall stubs on resume");
329
330		/* Clear stale vcpu_info. */
331		CPU_FOREACH(i)
332			DPCPU_ID_SET(i, vcpu_info, NULL);
333		break;
334	default:
335		panic("Unsupported HVM initialization type");
336	}
337
338	xen_vector_callback_enabled = 0;
339	xen_hvm_set_callback(NULL);
340
341	/*
342	 * On (PV)HVM domains we need to request the hypervisor to
343	 * fill the shared info page, for PVH guest the shared_info page
344	 * is passed inside the start_info struct and is already set, so this
345	 * functions are no-ops.
346	 */
347	xen_hvm_init_shared_info_page();
348	xen_hvm_disable_emulated_devices();
349}
350
351void
352xen_hvm_suspend(void)
353{
354}
355
356void
357xen_hvm_resume(bool suspend_cancelled)
358{
359
360	xen_hvm_init(suspend_cancelled ?
361	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
362
363	/* Register vcpu_info area for CPU#0. */
364	xen_hvm_cpu_init();
365}
366
367static void
368xen_hvm_sysinit(void *arg __unused)
369{
370	xen_hvm_init(XEN_HVM_INIT_COLD);
371}
372
373static void
374xen_set_vcpu_id(void)
375{
376	struct pcpu *pc;
377	int i;
378
379	if (!xen_hvm_domain())
380		return;
381
382	/* Set vcpu_id to acpi_id */
383	CPU_FOREACH(i) {
384		pc = pcpu_find(i);
385		pc->pc_vcpu_id = pc->pc_acpi_id;
386		if (bootverbose)
387			printf("XEN: CPU %u has VCPU ID %u\n",
388			       i, pc->pc_vcpu_id);
389	}
390}
391
392static void
393xen_hvm_cpu_init(void)
394{
395	struct vcpu_register_vcpu_info info;
396	struct vcpu_info *vcpu_info;
397	int cpu, rc;
398
399	if (!xen_domain())
400		return;
401
402	if (DPCPU_GET(vcpu_info) != NULL) {
403		/*
404		 * vcpu_info is already set.  We're resuming
405		 * from a failed migration and our pre-suspend
406		 * configuration is still valid.
407		 */
408		return;
409	}
410
411	vcpu_info = DPCPU_PTR(vcpu_local_info);
412	cpu = PCPU_GET(vcpu_id);
413	info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT;
414	info.offset = vtophys(vcpu_info) - trunc_page(vtophys(vcpu_info));
415
416	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
417	if (rc != 0)
418		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
419	else
420		DPCPU_SET(vcpu_info, vcpu_info);
421}
422
423SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
424SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
425SYSINIT(xen_set_vcpu_id, SI_SUB_CPU, SI_ORDER_ANY, xen_set_vcpu_id, NULL);
426