xref: /freebsd/sys/x86/xen/hvm.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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 		do_cpuid(base + 1, regs);
138 		printf("XEN: Hypervisor version %d.%d detected.\n",
139 		    regs[0] >> 16, regs[0] & 0xffff);
140 	}
141 
142 	/*
143 	 * Find the hypercall pages.
144 	 */
145 	do_cpuid(base + 2, regs);
146 
147 	for (i = 0; i < regs[0]; i++)
148 		wrmsr(regs[1], vtophys(&hypercall_page + i * PAGE_SIZE) + i);
149 
150 	return (0);
151 }
152 
153 static void
154 xen_hvm_init_shared_info_page(void)
155 {
156 	struct xen_add_to_physmap xatp;
157 
158 	if (xen_pv_domain()) {
159 		/*
160 		 * Already setup in the PV case, shared_info is passed inside
161 		 * of the start_info struct at start of day.
162 		 */
163 		return;
164 	}
165 
166 	if (HYPERVISOR_shared_info == NULL) {
167 		HYPERVISOR_shared_info = malloc(PAGE_SIZE, M_XENHVM, M_NOWAIT);
168 		if (HYPERVISOR_shared_info == NULL)
169 			panic("Unable to allocate Xen shared info page");
170 	}
171 
172 	xatp.domid = DOMID_SELF;
173 	xatp.idx = 0;
174 	xatp.space = XENMAPSPACE_shared_info;
175 	xatp.gpfn = vtophys(HYPERVISOR_shared_info) >> PAGE_SHIFT;
176 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
177 		panic("HYPERVISOR_memory_op failed");
178 }
179 
180 /*
181  * Tell the hypervisor how to contact us for event channel callbacks.
182  */
183 void
184 xen_hvm_set_callback(device_t dev)
185 {
186 	struct xen_hvm_param xhp;
187 	int irq;
188 
189 	if (xen_vector_callback_enabled)
190 		return;
191 
192 	xhp.domid = DOMID_SELF;
193 	xhp.index = HVM_PARAM_CALLBACK_IRQ;
194 	if (xen_feature(XENFEAT_hvm_callback_vector) != 0) {
195 		int error;
196 
197 		xhp.value = HVM_CALLBACK_VECTOR(IDT_EVTCHN);
198 		error = HYPERVISOR_hvm_op(HVMOP_set_param, &xhp);
199 		if (error == 0) {
200 			xen_vector_callback_enabled = 1;
201 			return;
202 		}
203 		printf("Xen HVM callback vector registration failed (%d). "
204 		    "Falling back to emulated device interrupt\n", error);
205 	}
206 	xen_vector_callback_enabled = 0;
207 	if (dev == NULL) {
208 		/*
209 		 * Called from early boot or resume.
210 		 * xenpci will invoke us again later.
211 		 */
212 		return;
213 	}
214 
215 	irq = pci_get_irq(dev);
216 	if (irq < 16) {
217 		xhp.value = HVM_CALLBACK_GSI(irq);
218 	} else {
219 		u_int slot;
220 		u_int pin;
221 
222 		slot = pci_get_slot(dev);
223 		pin = pci_get_intpin(dev) - 1;
224 		xhp.value = HVM_CALLBACK_PCI_INTX(slot, pin);
225 	}
226 
227 	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp) != 0)
228 		panic("Can't set evtchn callback");
229 }
230 
231 #define	XEN_MAGIC_IOPORT 0x10
232 enum {
233 	XMI_MAGIC			 = 0x49d2,
234 	XMI_UNPLUG_IDE_DISKS		 = 0x01,
235 	XMI_UNPLUG_NICS			 = 0x02,
236 	XMI_UNPLUG_IDE_EXCEPT_PRI_MASTER = 0x04
237 };
238 
239 static void
240 xen_hvm_disable_emulated_devices(void)
241 {
242 	u_short disable_devs = 0;
243 
244 	if (xen_pv_domain()) {
245 		/*
246 		 * No emulated devices in the PV case, so no need to unplug
247 		 * anything.
248 		 */
249 		if (xen_disable_pv_disks != 0 || xen_disable_pv_nics != 0)
250 			printf("PV devices cannot be disabled in PV guests\n");
251 		return;
252 	}
253 
254 	if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC)
255 		return;
256 
257 	if (xen_disable_pv_disks == 0) {
258 		if (bootverbose)
259 			printf("XEN: disabling emulated disks\n");
260 		disable_devs |= XMI_UNPLUG_IDE_DISKS;
261 	}
262 	if (xen_disable_pv_nics == 0) {
263 		if (bootverbose)
264 			printf("XEN: disabling emulated nics\n");
265 		disable_devs |= XMI_UNPLUG_NICS;
266 	}
267 
268 	if (disable_devs != 0)
269 		outw(XEN_MAGIC_IOPORT, disable_devs);
270 }
271 
272 static void
273 xen_hvm_init(enum xen_hvm_init_type init_type)
274 {
275 	int error;
276 	int i;
277 
278 	if (init_type == XEN_HVM_INIT_CANCELLED_SUSPEND)
279 		return;
280 
281 	error = xen_hvm_init_hypercall_stubs(init_type);
282 
283 	switch (init_type) {
284 	case XEN_HVM_INIT_COLD:
285 		if (error != 0)
286 			return;
287 
288 		/*
289 		 * If xen_domain_type is not set at this point
290 		 * it means we are inside a (PV)HVM guest, because
291 		 * for PVH the guest type is set much earlier
292 		 * (see hammer_time_xen).
293 		 */
294 		if (!xen_domain()) {
295 			xen_domain_type = XEN_HVM_DOMAIN;
296 			vm_guest = VM_GUEST_XEN;
297 		}
298 
299 		setup_xen_features();
300 #ifdef SMP
301 		cpu_ops = xen_hvm_cpu_ops;
302 #endif
303 		break;
304 	case XEN_HVM_INIT_RESUME:
305 		if (error != 0)
306 			panic("Unable to init Xen hypercall stubs on resume");
307 
308 		/* Clear stale vcpu_info. */
309 		CPU_FOREACH(i)
310 			DPCPU_ID_SET(i, vcpu_info, NULL);
311 		break;
312 	default:
313 		panic("Unsupported HVM initialization type");
314 	}
315 
316 	xen_vector_callback_enabled = 0;
317 	xen_hvm_set_callback(NULL);
318 
319 	/*
320 	 * On (PV)HVM domains we need to request the hypervisor to
321 	 * fill the shared info page, for PVH guest the shared_info page
322 	 * is passed inside the start_info struct and is already set, so this
323 	 * functions are no-ops.
324 	 */
325 	xen_hvm_init_shared_info_page();
326 	xen_hvm_disable_emulated_devices();
327 }
328 
329 void
330 xen_hvm_suspend(void)
331 {
332 }
333 
334 void
335 xen_hvm_resume(bool suspend_cancelled)
336 {
337 
338 	xen_hvm_init(suspend_cancelled ?
339 	    XEN_HVM_INIT_CANCELLED_SUSPEND : XEN_HVM_INIT_RESUME);
340 
341 	/* Register vcpu_info area for CPU#0. */
342 	xen_hvm_cpu_init();
343 }
344 
345 static void
346 xen_hvm_sysinit(void *arg __unused)
347 {
348 	xen_hvm_init(XEN_HVM_INIT_COLD);
349 }
350 
351 static void
352 xen_set_vcpu_id(void)
353 {
354 	struct pcpu *pc;
355 	int i;
356 
357 	if (!xen_hvm_domain())
358 		return;
359 
360 	/* Set vcpu_id to acpi_id */
361 	CPU_FOREACH(i) {
362 		pc = pcpu_find(i);
363 		pc->pc_vcpu_id = pc->pc_acpi_id;
364 		if (bootverbose)
365 			printf("XEN: CPU %u has VCPU ID %u\n",
366 			       i, pc->pc_vcpu_id);
367 	}
368 }
369 
370 static void
371 xen_hvm_cpu_init(void)
372 {
373 	struct vcpu_register_vcpu_info info;
374 	struct vcpu_info *vcpu_info;
375 	int cpu, rc;
376 
377 	if (!xen_domain())
378 		return;
379 
380 	if (DPCPU_GET(vcpu_info) != NULL) {
381 		/*
382 		 * vcpu_info is already set.  We're resuming
383 		 * from a failed migration and our pre-suspend
384 		 * configuration is still valid.
385 		 */
386 		return;
387 	}
388 
389 	vcpu_info = DPCPU_PTR(vcpu_local_info);
390 	cpu = PCPU_GET(vcpu_id);
391 	info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT;
392 	info.offset = vtophys(vcpu_info) - trunc_page(vtophys(vcpu_info));
393 
394 	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
395 	if (rc != 0)
396 		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
397 	else
398 		DPCPU_SET(vcpu_info, vcpu_info);
399 }
400 
401 SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL);
402 SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL);
403 SYSINIT(xen_set_vcpu_id, SI_SUB_CPU, SI_ORDER_ANY, xen_set_vcpu_id, NULL);
404