xref: /freebsd/sys/x86/xen/hvm.c (revision ff0ba87247820afbdfdc1b307c803f7923d0e4d3)
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 void xen_hvm_cpu_resume(void);
63 #endif
64 static void xen_hvm_cpu_init(void);
65 
66 /*---------------------------- Extern Declarations ---------------------------*/
67 /* Variables used by mp_machdep to perform the bitmap IPI */
68 extern volatile u_int cpu_ipi_pending[MAXCPU];
69 
70 /*-------------------------------- Local Types -------------------------------*/
71 enum xen_hvm_init_type {
72 	XEN_HVM_INIT_COLD,
73 	XEN_HVM_INIT_CANCELLED_SUSPEND,
74 	XEN_HVM_INIT_RESUME
75 };
76 
77 /*-------------------------------- Global Data -------------------------------*/
78 enum xen_domain_type xen_domain_type = XEN_NATIVE;
79 
80 #ifdef SMP
81 struct cpu_ops xen_hvm_cpu_ops = {
82 	.cpu_init	= xen_hvm_cpu_init,
83 	.cpu_resume	= xen_hvm_cpu_resume
84 };
85 #endif
86 
87 static MALLOC_DEFINE(M_XENHVM, "xen_hvm", "Xen HVM PV Support");
88 
89 /**
90  * If non-zero, the hypervisor has been configured to use a direct
91  * IDT event callback for interrupt injection.
92  */
93 int xen_vector_callback_enabled;
94 
95 /*------------------------------- Per-CPU Data -------------------------------*/
96 DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
97 DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
98 
99 /*------------------ Hypervisor Access Shared Memory Regions -----------------*/
100 shared_info_t *HYPERVISOR_shared_info;
101 start_info_t *HYPERVISOR_start_info;
102 
103 #ifdef SMP
104 /* XEN diverged cpu operations */
105 static void
106 xen_hvm_cpu_resume(void)
107 {
108 	u_int cpuid = PCPU_GET(cpuid);
109 
110 	/*
111 	 * Reset pending bitmap IPIs, because Xen doesn't preserve pending
112 	 * event channels on migration.
113 	 */
114 	cpu_ipi_pending[cpuid] = 0;
115 
116 	/* register vcpu_info area */
117 	xen_hvm_cpu_init();
118 }
119 #endif
120 /*---------------------- XEN Hypervisor Probe and Setup ----------------------*/
121 static uint32_t
122 xen_hvm_cpuid_base(void)
123 {
124 	uint32_t base, regs[4];
125 
126 	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
127 		do_cpuid(base, regs);
128 		if (!memcmp("XenVMMXenVMM", &regs[1], 12)
129 		    && (regs[0] - base) >= 2)
130 			return (base);
131 	}
132 	return (0);
133 }
134 
135 /*
136  * Allocate and fill in the hypcall page.
137  */
138 static int
139 xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)
140 {
141 	uint32_t base, regs[4];
142 	int i;
143 
144 	if (xen_pv_domain()) {
145 		/* hypercall page is already set in the PV case */
146 		return (0);
147 	}
148 
149 	base = xen_hvm_cpuid_base();
150 	if (base == 0)
151 		return (ENXIO);
152 
153 	if (init_type == XEN_HVM_INIT_COLD) {
154 		do_cpuid(base + 1, regs);
155 		printf("XEN: Hypervisor version %d.%d detected.\n",
156 		    regs[0] >> 16, regs[0] & 0xffff);
157 	}
158 
159 	/*
160 	 * Find the hypercall pages.
161 	 */
162 	do_cpuid(base + 2, regs);
163 
164 	for (i = 0; i < regs[0]; i++)
165 		wrmsr(regs[1], vtophys(&hypercall_page + i * PAGE_SIZE) + i);
166 
167 	return (0);
168 }
169 
170 static void
171 xen_hvm_init_shared_info_page(void)
172 {
173 	struct xen_add_to_physmap xatp;
174 
175 	if (xen_pv_domain()) {
176 		/*
177 		 * Already setup in the PV case, shared_info is passed inside
178 		 * of the start_info struct at start of day.
179 		 */
180 		return;
181 	}
182 
183 	if (HYPERVISOR_shared_info == NULL) {
184 		HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
185 		if (HYPERVISOR_shared_info == NULL)
186 			panic("Unable to allocate Xen shared info page");
187 	}
188 
189 	xatp.domid = DOMID_SELF;
190 	xatp.idx = 0;
191 	xatp.space = XENMAPSPACE_shared_info;
192 	xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
193 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
194 		panic("HYPERVISOR_memory_op failed");
195 }
196 
197 /*
198  * Tell the hypervisor how to contact us for event channel callbacks.
199  */
200 void
201 xen_hvm_set_callback(device_t dev)
202 {
203 	struct xen_hvm_param xhp;
204 	int irq;
205 
206 	if (xen_vector_callback_enabled)
207 		return;
208 
209 	xhp.domid = DOMID_SELF;
210 	xhp.index = HVM_PARAM_CALLBACK_IRQ;
211 	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
212 		int error;
213 
214 		xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
215 		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
216 		if (error == 0) {
217 			xen_vector_callback_enabled = 1;
218 			return;
219 		}
220 		printf("Xen HVM callback vector registration failed (%d). "
221 		    "Falling back to emulated device interrupt\n", error);
222 	}
223 	xen_vector_callback_enabled = 0;
224 	if (dev == NULL) {
225 		/*
226 		 * Called from early boot or resume.
227 		 * xenpci will invoke us again later.
228 		 */
229 		return;
230 	}
231 
232 	irq = pci_get_irq(dev);
233 	if (irq < 16) {
234 		xhp.value = HVM_CALLBACK_GSI(irq);
235 	} else {
236 		u_int slot;
237 		u_int pin;
238 
239 		slot = pci_get_slot(dev);
240 		pin = pci_get_intpin(dev) - 1;
241 		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
242 	}
243 
244 	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
245 		panic("Can't set evtchn callback");
246 }
247 
248 #define	XEN_MAGIC_IOPORT 0x10
249 enum {
250 	XMI_MAGIC			 = 0x49d2,
251 	XMI_UNPLUG_IDE_DISKS		 = 0x01,
252 	XMI_UNPLUG_NICS			 = 0x02,
253 	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
254 };
255 
256 static void
257 xen_hvm_disable_emulated_devices(void)
258 {
259 
260 	if (xen_pv_domain()) {
261 		/*
262 		 * No emulated devices in the PV case, so no need to unplug
263 		 * anything.
264 		 */
265 		return;
266 	}
267 
268 	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
269 		return;
270 
271 	if (bootverbose)
272 		printf("XEN: Disabling emulated block and network devices\n");
273 	outw(XEN_MAGIC_IOPORT, XMI_UNPLUG_IDE_DISKS|XMI_UNPLUG_NICS);
274 }
275 
276 static void
277 xen_hvm_init(enum xen_hvm_init_type init_type)
278 {
279 	int error;
280 	int i;
281 
282 	if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
283 		return;
284 
285 	error = xen_hvm_init_hypercall_stubs(init_type);
286 
287 	switch (init_type) {
288 	case XEN_HVM_INIT_COLD:
289 		if (error != 0)
290 			return;
291 
292 		/*
293 		 * If xen_domain_type is not set at this point
294 		 * it means we are inside a (PV)HVM guest, because
295 		 * for PVH the guest type is set much earlier
296 		 * (see hammer_time_xen).
297 		 */
298 		if (!xen_domain()) {
299 			xen_domain_type = XEN_HVM_DOMAIN;
300 			vm_guest = VM_GUEST_XEN;
301 		}
302 
303 		setup_xen_features();
304 #ifdef SMP
305 		cpu_ops = xen_hvm_cpu_ops;
306 #endif
307 		break;
308 	case XEN_HVM_INIT_RESUME:
309 		if (error != 0)
310 			panic("Unable to init Xen hypercall stubs on resume");
311 
312 		/* Clear stale vcpu_info. */
313 		CPU_FOREACH(i)
314 			DPCPU_ID_SET(i, vcpu_info, NULL);
315 		break;
316 	default:
317 		panic("Unsupported HVM initialization type");
318 	}
319 
320 	xen_vector_callback_enabled = 0;
321 	xen_hvm_set_callback(NULL);
322 
323 	/*
324 	 * On (PV)HVM domains we need to request the hypervisor to
325 	 * fill the shared info page, for PVH guest the shared_info page
326 	 * is passed inside the start_info struct and is already set, so this
327 	 * functions are no-ops.
328 	 */
329 	xen_hvm_init_shared_info_page();
330 	xen_hvm_disable_emulated_devices();
331 }
332 
333 void
334 xen_hvm_suspend(void)
335 {
336 }
337 
338 void
339 xen_hvm_resume(bool suspend_cancelled)
340 {
341 
342 	xen_hvm_init(suspend_cancelled ?
343 	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
344 
345 	/* Register vcpu_info area for CPU#0. */
346 	xen_hvm_cpu_init();
347 }
348 
349 static void
350 xen_hvm_sysinit(void *arg __unused)
351 {
352 	xen_hvm_init(XEN_HVM_INIT_COLD);
353 }
354 
355 static void
356 xen_set_vcpu_id(void)
357 {
358 	struct pcpu *pc;
359 	int i;
360 
361 	if (!xen_hvm_domain())
362 		return;
363 
364 	/* Set vcpu_id to acpi_id */
365 	CPU_FOREACH(i) {
366 		pc = pcpu_find(i);
367 		pc->pc_vcpu_id = pc->pc_acpi_id;
368 		if (bootverbose)
369 			printf("XEN: CPU %u has VCPU ID %u\n",
370 			       i, pc->pc_vcpu_id);
371 	}
372 }
373 
374 static void
375 xen_hvm_cpu_init(void)
376 {
377 	struct vcpu_register_vcpu_info info;
378 	struct vcpu_info *vcpu_info;
379 	int cpu, rc;
380 
381 	if (!xen_domain())
382 		return;
383 
384 	if (DPCPU_GET(vcpu_info) != NULL) {
385 		/*
386 		 * vcpu_info is already set.  We're resuming
387 		 * from a failed migration and our pre-suspend
388 		 * configuration is still valid.
389 		 */
390 		return;
391 	}
392 
393 	vcpu_info = DPCPU_PTR(vcpu_local_info);
394 	cpu = PCPU_GET(vcpu_id);
395 	info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT;
396 	info.offset = vtophys(vcpu_info) - trunc_page(vtophys(vcpu_info));
397 
398 	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
399 	if (rc != 0)
400 		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
401 	else
402 		DPCPU_SET(vcpu_info, vcpu_info);
403 }
404 
405 SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
406 SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
407 SYSINIT(xen_set_vcpu_id, SI_SUB_CPU, SI_ORDER_ANY, xen_set_vcpu_id, NULL);
408