xref: /freebsd/sys/x86/xen/hvm.c (revision 2c8d04d0228871c24017509cf039e7c5d97d97be)
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 static void xen_hvm_cpu_init(void);
62 
63 /*-------------------------------- Local Types -------------------------------*/
64 enum 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 -------------------------------*/
71 enum xen_domain_type xen_domain_type = XEN_NATIVE;
72 
73 #ifdef SMP
74 struct cpu_ops xen_hvm_cpu_ops = {
75 	.cpu_init	= xen_hvm_cpu_init,
76 	.cpu_resume	= xen_hvm_cpu_init
77 };
78 #endif
79 
80 static 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  */
86 int xen_vector_callback_enabled;
87 
88 /*------------------------------- Per-CPU Data -------------------------------*/
89 DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
90 DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
91 
92 /*------------------ Hypervisor Access Shared Memory Regions -----------------*/
93 shared_info_t *HYPERVISOR_shared_info;
94 start_info_t *HYPERVISOR_start_info;
95 
96 
97 /*------------------------------ Sysctl tunables -----------------------------*/
98 int xen_disable_pv_disks = 0;
99 int xen_disable_pv_nics = 0;
100 TUNABLE_INT("hw.xen.disable_pv_disks", &xen_disable_pv_disks);
101 TUNABLE_INT("hw.xen.disable_pv_nics", &xen_disable_pv_nics);
102 
103 /*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
104 static uint32_t
105 xen_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  */
121 static int
122 xen_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 		if (((major < 4) || (major == 4 && minor <= 5)) &&
147 		    msix_disable_migration == -1) {
148 			/*
149 			 * Xen hypervisors prior to 4.6.0 do not properly
150 			 * handle updates to enabled MSI-X table entries,
151 			 * so disable MSI-X interrupt migration in that
152 			 * case.
153 			 */
154 			if (bootverbose)
155 				printf(
156 "Disabling MSI-X interrupt migration due to Xen hypervisor bug.\n"
157 "Set machdep.msix_disable_migration=0 to forcefully enable it.\n");
158 			msix_disable_migration = 1;
159 		}
160 	}
161 
162 	/*
163 	 * Find the hypercall pages.
164 	 */
165 	do_cpuid(base + 2, regs);
166 
167 	for (i = 0; i < regs[0]; i++)
168 		wrmsr(regs[1], vtophys(&hypercall_page + i * PAGE_SIZE) + i);
169 
170 	return (0);
171 }
172 
173 static void
174 xen_hvm_init_shared_info_page(void)
175 {
176 	struct xen_add_to_physmap xatp;
177 
178 	if (xen_pv_domain()) {
179 		/*
180 		 * Already setup in the PV case, shared_info is passed inside
181 		 * of the start_info struct at start of day.
182 		 */
183 		return;
184 	}
185 
186 	if (HYPERVISOR_shared_info == NULL) {
187 		HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
188 		if (HYPERVISOR_shared_info == NULL)
189 			panic("Unable to allocate Xen shared info page");
190 	}
191 
192 	xatp.domid = DOMID_SELF;
193 	xatp.idx = 0;
194 	xatp.space = XENMAPSPACE_shared_info;
195 	xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
196 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
197 		panic("HYPERVISOR_memory_op failed");
198 }
199 
200 /*
201  * Tell the hypervisor how to contact us for event channel callbacks.
202  */
203 void
204 xen_hvm_set_callback(device_t dev)
205 {
206 	struct xen_hvm_param xhp;
207 	int irq;
208 
209 	if (xen_vector_callback_enabled)
210 		return;
211 
212 	xhp.domid = DOMID_SELF;
213 	xhp.index = HVM_PARAM_CALLBACK_IRQ;
214 	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
215 		int error;
216 
217 		xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
218 		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
219 		if (error == 0) {
220 			xen_vector_callback_enabled = 1;
221 			return;
222 		}
223 		printf("Xen HVM callback vector registration failed (%d). "
224 		    "Falling back to emulated device interrupt\n", error);
225 	}
226 	xen_vector_callback_enabled = 0;
227 	if (dev == NULL) {
228 		/*
229 		 * Called from early boot or resume.
230 		 * xenpci will invoke us again later.
231 		 */
232 		return;
233 	}
234 
235 	irq = pci_get_irq(dev);
236 	if (irq < 16) {
237 		xhp.value = HVM_CALLBACK_GSI(irq);
238 	} else {
239 		u_int slot;
240 		u_int pin;
241 
242 		slot = pci_get_slot(dev);
243 		pin = pci_get_intpin(dev) - 1;
244 		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
245 	}
246 
247 	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
248 		panic("Can't set evtchn callback");
249 }
250 
251 #define	XEN_MAGIC_IOPORT 0x10
252 enum {
253 	XMI_MAGIC			 = 0x49d2,
254 	XMI_UNPLUG_IDE_DISKS		 = 0x01,
255 	XMI_UNPLUG_NICS			 = 0x02,
256 	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
257 };
258 
259 static void
260 xen_hvm_disable_emulated_devices(void)
261 {
262 	u_short disable_devs = 0;
263 
264 	if (xen_pv_domain()) {
265 		/*
266 		 * No emulated devices in the PV case, so no need to unplug
267 		 * anything.
268 		 */
269 		if (xen_disable_pv_disks != 0 || xen_disable_pv_nics != 0)
270 			printf("PV devices cannot be disabled in PV guests\n");
271 		return;
272 	}
273 
274 	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
275 		return;
276 
277 	if (xen_disable_pv_disks == 0) {
278 		if (bootverbose)
279 			printf("XEN: disabling emulated disks\n");
280 		disable_devs |= XMI_UNPLUG_IDE_DISKS;
281 	}
282 	if (xen_disable_pv_nics == 0) {
283 		if (bootverbose)
284 			printf("XEN: disabling emulated nics\n");
285 		disable_devs |= XMI_UNPLUG_NICS;
286 	}
287 
288 	if (disable_devs != 0)
289 		outw(XEN_MAGIC_IOPORT, disable_devs);
290 }
291 
292 static void
293 xen_hvm_init(enum xen_hvm_init_type init_type)
294 {
295 	int error;
296 	int i;
297 
298 	if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
299 		return;
300 
301 	error = xen_hvm_init_hypercall_stubs(init_type);
302 
303 	switch (init_type) {
304 	case XEN_HVM_INIT_COLD:
305 		if (error != 0)
306 			return;
307 
308 		/*
309 		 * If xen_domain_type is not set at this point
310 		 * it means we are inside a (PV)HVM guest, because
311 		 * for PVH the guest type is set much earlier
312 		 * (see hammer_time_xen).
313 		 */
314 		if (!xen_domain()) {
315 			xen_domain_type = XEN_HVM_DOMAIN;
316 			vm_guest = VM_GUEST_XEN;
317 		}
318 
319 		setup_xen_features();
320 #ifdef SMP
321 		cpu_ops = xen_hvm_cpu_ops;
322 #endif
323 		break;
324 	case XEN_HVM_INIT_RESUME:
325 		if (error != 0)
326 			panic("Unable to init Xen hypercall stubs on resume");
327 
328 		/* Clear stale vcpu_info. */
329 		CPU_FOREACH(i)
330 			DPCPU_ID_SET(i, vcpu_info, NULL);
331 		break;
332 	default:
333 		panic("Unsupported HVM initialization type");
334 	}
335 
336 	xen_vector_callback_enabled = 0;
337 	xen_hvm_set_callback(NULL);
338 
339 	/*
340 	 * On (PV)HVM domains we need to request the hypervisor to
341 	 * fill the shared info page, for PVH guest the shared_info page
342 	 * is passed inside the start_info struct and is already set, so this
343 	 * functions are no-ops.
344 	 */
345 	xen_hvm_init_shared_info_page();
346 	xen_hvm_disable_emulated_devices();
347 }
348 
349 void
350 xen_hvm_suspend(void)
351 {
352 }
353 
354 void
355 xen_hvm_resume(bool suspend_cancelled)
356 {
357 
358 	xen_hvm_init(suspend_cancelled ?
359 	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
360 
361 	/* Register vcpu_info area for CPU#0. */
362 	xen_hvm_cpu_init();
363 }
364 
365 static void
366 xen_hvm_sysinit(void *arg __unused)
367 {
368 	xen_hvm_init(XEN_HVM_INIT_COLD);
369 }
370 
371 static void
372 xen_set_vcpu_id(void)
373 {
374 	struct pcpu *pc;
375 	int i;
376 
377 	if (!xen_hvm_domain())
378 		return;
379 
380 	/* Set vcpu_id to acpi_id */
381 	CPU_FOREACH(i) {
382 		pc = pcpu_find(i);
383 		pc->pc_vcpu_id = pc->pc_acpi_id;
384 		if (bootverbose)
385 			printf("XEN: CPU %u has VCPU ID %u\n",
386 			       i, pc->pc_vcpu_id);
387 	}
388 }
389 
390 static void
391 xen_hvm_cpu_init(void)
392 {
393 	struct vcpu_register_vcpu_info info;
394 	struct vcpu_info *vcpu_info;
395 	int cpu, rc;
396 
397 	if (!xen_domain())
398 		return;
399 
400 	if (DPCPU_GET(vcpu_info) != NULL) {
401 		/*
402 		 * vcpu_info is already set.  We're resuming
403 		 * from a failed migration and our pre-suspend
404 		 * configuration is still valid.
405 		 */
406 		return;
407 	}
408 
409 	vcpu_info = DPCPU_PTR(vcpu_local_info);
410 	cpu = PCPU_GET(vcpu_id);
411 	info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT;
412 	info.offset = vtophys(vcpu_info) - trunc_page(vtophys(vcpu_info));
413 
414 	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
415 	if (rc != 0)
416 		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
417 	else
418 		DPCPU_SET(vcpu_info, vcpu_info);
419 }
420 
421 SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
422 SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
423 SYSINIT(xen_set_vcpu_id, SI_SUB_CPU, SI_ORDER_ANY, xen_set_vcpu_id, NULL);
424