xref: /freebsd/sys/x86/xen/pv.c (revision 0572ccaa4543b0abef8ef81e384c1d04de9f3da1)
1 /*
2  * Copyright (c) 2004 Christian Limpach.
3  * Copyright (c) 2004-2006,2008 Kip Macy
4  * Copyright (c) 2013 Roger Pau Monné <roger.pau@citrix.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/kernel.h>
35 #include <sys/reboot.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/lock.h>
39 #include <sys/rwlock.h>
40 #include <sys/boot.h>
41 #include <sys/ctype.h>
42 #include <sys/mutex.h>
43 #include <sys/smp.h>
44 
45 #include <vm/vm.h>
46 #include <vm/vm_extern.h>
47 #include <vm/vm_kern.h>
48 #include <vm/vm_page.h>
49 #include <vm/vm_map.h>
50 #include <vm/vm_object.h>
51 #include <vm/vm_pager.h>
52 #include <vm/vm_param.h>
53 
54 #include <x86/init.h>
55 #include <machine/pc/bios.h>
56 #include <machine/smp.h>
57 
58 #include <xen/xen-os.h>
59 #include <xen/hypervisor.h>
60 #include <xen/xenstore/xenstorevar.h>
61 
62 #include <xen/interface/vcpu.h>
63 
64 #include <dev/xen/timer/timer.h>
65 
66 /* Native initial function */
67 extern u_int64_t hammer_time(u_int64_t, u_int64_t);
68 /* Xen initial function */
69 uint64_t hammer_time_xen(start_info_t *, uint64_t);
70 
71 #define MAX_E820_ENTRIES	128
72 
73 /*--------------------------- Forward Declarations ---------------------------*/
74 static caddr_t xen_pv_parse_preload_data(u_int64_t);
75 static void xen_pv_parse_memmap(caddr_t, vm_paddr_t *, int *);
76 
77 #ifdef SMP
78 static int xen_pv_start_all_aps(void);
79 #endif
80 
81 /*---------------------------- Extern Declarations ---------------------------*/
82 #ifdef SMP
83 /* Variables used by amd64 mp_machdep to start APs */
84 extern struct mtx ap_boot_mtx;
85 extern void *bootstacks[];
86 extern char *doublefault_stack;
87 extern char *nmi_stack;
88 extern void *dpcpu;
89 extern int bootAP;
90 extern char *bootSTK;
91 #endif
92 
93 /*-------------------------------- Global Data -------------------------------*/
94 /* Xen init_ops implementation. */
95 struct init_ops xen_init_ops = {
96 	.parse_preload_data =	xen_pv_parse_preload_data,
97 	.early_clock_source_init =	xen_clock_init,
98 	.early_delay =			xen_delay,
99 	.parse_memmap =			xen_pv_parse_memmap,
100 #ifdef SMP
101 	.start_all_aps =		xen_pv_start_all_aps,
102 #endif
103 };
104 
105 static struct bios_smap xen_smap[MAX_E820_ENTRIES];
106 
107 /*-------------------------------- Xen PV init -------------------------------*/
108 /*
109  * First function called by the Xen PVH boot sequence.
110  *
111  * Set some Xen global variables and prepare the environment so it is
112  * as similar as possible to what native FreeBSD init function expects.
113  */
114 uint64_t
115 hammer_time_xen(start_info_t *si, uint64_t xenstack)
116 {
117 	uint64_t physfree;
118 	uint64_t *PT4 = (u_int64_t *)xenstack;
119 	uint64_t *PT3 = (u_int64_t *)(xenstack + PAGE_SIZE);
120 	uint64_t *PT2 = (u_int64_t *)(xenstack + 2 * PAGE_SIZE);
121 	int i;
122 
123 	xen_domain_type = XEN_PV_DOMAIN;
124 	vm_guest = VM_GUEST_XEN;
125 
126 	if ((si == NULL) || (xenstack == 0)) {
127 		xc_printf("ERROR: invalid start_info or xen stack, halting\n");
128 		HYPERVISOR_shutdown(SHUTDOWN_crash);
129 	}
130 
131 	xc_printf("FreeBSD PVH running on %s\n", si->magic);
132 
133 	/* We use 3 pages of xen stack for the boot pagetables */
134 	physfree = xenstack + 3 * PAGE_SIZE - KERNBASE;
135 
136 	/* Setup Xen global variables */
137 	HYPERVISOR_start_info = si;
138 	HYPERVISOR_shared_info =
139 	    (shared_info_t *)(si->shared_info + KERNBASE);
140 
141 	/*
142 	 * Setup some misc global variables for Xen devices
143 	 *
144 	 * XXX: Devices that need these specific variables should
145 	 *      be rewritten to fetch this info by themselves from the
146 	 *      start_info page.
147 	 */
148 	xen_store = (struct xenstore_domain_interface *)
149 	    (ptoa(si->store_mfn) + KERNBASE);
150 	console_page = (char *)(ptoa(si->console.domU.mfn) + KERNBASE);
151 
152 	/*
153 	 * Use the stack Xen gives us to build the page tables
154 	 * as native FreeBSD expects to find them (created
155 	 * by the boot trampoline).
156 	 */
157 	for (i = 0; i < (PAGE_SIZE / sizeof(uint64_t)); i++) {
158 		/* Each slot of the level 4 pages points to the same level 3 page */
159 		PT4[i] = ((uint64_t)&PT3[0]) - KERNBASE;
160 		PT4[i] |= PG_V | PG_RW | PG_U;
161 
162 		/* Each slot of the level 3 pages points to the same level 2 page */
163 		PT3[i] = ((uint64_t)&PT2[0]) - KERNBASE;
164 		PT3[i] |= PG_V | PG_RW | PG_U;
165 
166 		/* The level 2 page slots are mapped with 2MB pages for 1GB. */
167 		PT2[i] = i * (2 * 1024 * 1024);
168 		PT2[i] |= PG_V | PG_RW | PG_PS | PG_U;
169 	}
170 	load_cr3(((uint64_t)&PT4[0]) - KERNBASE);
171 
172 	/* Set the hooks for early functions that diverge from bare metal */
173 	init_ops = xen_init_ops;
174 
175 	/* Now we can jump into the native init function */
176 	return (hammer_time(0, physfree));
177 }
178 
179 /*-------------------------------- PV specific -------------------------------*/
180 #ifdef SMP
181 static bool
182 start_xen_ap(int cpu)
183 {
184 	struct vcpu_guest_context *ctxt;
185 	int ms, cpus = mp_naps;
186 	const size_t stacksize = KSTACK_PAGES * PAGE_SIZE;
187 
188 	/* allocate and set up an idle stack data page */
189 	bootstacks[cpu] =
190 	    (void *)kmem_malloc(kernel_arena, stacksize, M_WAITOK | M_ZERO);
191 	doublefault_stack =
192 	    (char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
193 	nmi_stack =
194 	    (char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
195 	dpcpu =
196 	    (void *)kmem_malloc(kernel_arena, DPCPU_SIZE, M_WAITOK | M_ZERO);
197 
198 	bootSTK = (char *)bootstacks[cpu] + KSTACK_PAGES * PAGE_SIZE - 8;
199 	bootAP = cpu;
200 
201 	ctxt = malloc(sizeof(*ctxt), M_TEMP, M_WAITOK | M_ZERO);
202 	if (ctxt == NULL)
203 		panic("unable to allocate memory");
204 
205 	ctxt->flags = VGCF_IN_KERNEL;
206 	ctxt->user_regs.rip = (unsigned long) init_secondary;
207 	ctxt->user_regs.rsp = (unsigned long) bootSTK;
208 
209 	/* Set the AP to use the same page tables */
210 	ctxt->ctrlreg[3] = KPML4phys;
211 
212 	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
213 		panic("unable to initialize AP#%d", cpu);
214 
215 	free(ctxt, M_TEMP);
216 
217 	/* Launch the vCPU */
218 	if (HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
219 		panic("unable to start AP#%d", cpu);
220 
221 	/* Wait up to 5 seconds for it to start. */
222 	for (ms = 0; ms < 5000; ms++) {
223 		if (mp_naps > cpus)
224 			return (true);
225 		DELAY(1000);
226 	}
227 
228 	return (false);
229 }
230 
231 static int
232 xen_pv_start_all_aps(void)
233 {
234 	int cpu;
235 
236 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
237 
238 	for (cpu = 1; cpu < mp_ncpus; cpu++) {
239 
240 		/* attempt to start the Application Processor */
241 		if (!start_xen_ap(cpu))
242 			panic("AP #%d failed to start!", cpu);
243 
244 		CPU_SET(cpu, &all_cpus);	/* record AP in CPU map */
245 	}
246 
247 	return (mp_naps);
248 }
249 #endif /* SMP */
250 
251 /*
252  * Functions to convert the "extra" parameters passed by Xen
253  * into FreeBSD boot options.
254  */
255 static void
256 xen_pv_set_env(void)
257 {
258 	char *cmd_line_next, *cmd_line;
259 	size_t env_size;
260 
261 	cmd_line = HYPERVISOR_start_info->cmd_line;
262 	env_size = sizeof(HYPERVISOR_start_info->cmd_line);
263 
264 	/* Skip leading spaces */
265 	for (; isspace(*cmd_line) && (env_size != 0); cmd_line++)
266 		env_size--;
267 
268 	/* Replace ',' with '\0' */
269 	for (cmd_line_next = cmd_line; strsep(&cmd_line_next, ",") != NULL;)
270 		;
271 
272 	init_static_kenv(cmd_line, env_size);
273 }
274 
275 static void
276 xen_pv_set_boothowto(void)
277 {
278 	int i;
279 
280 	/* get equivalents from the environment */
281 	for (i = 0; howto_names[i].ev != NULL; i++) {
282 		if (getenv(howto_names[i].ev) != NULL)
283 			boothowto |= howto_names[i].mask;
284 	}
285 }
286 
287 static caddr_t
288 xen_pv_parse_preload_data(u_int64_t modulep)
289 {
290 	/* Parse the extra boot information given by Xen */
291 	xen_pv_set_env();
292 	xen_pv_set_boothowto();
293 
294 	return (NULL);
295 }
296 
297 static void
298 xen_pv_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
299 {
300 	struct xen_memory_map memmap;
301 	u_int32_t size;
302 	int rc;
303 
304 	/* Fetch the E820 map from Xen */
305 	memmap.nr_entries = MAX_E820_ENTRIES;
306 	set_xen_guest_handle(memmap.buffer, xen_smap);
307 	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
308 	if (rc)
309 		panic("unable to fetch Xen E820 memory map");
310 	size = memmap.nr_entries * sizeof(xen_smap[0]);
311 
312 	bios_add_smap_entries(xen_smap, size, physmap, physmap_idx);
313 }
314