1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2015 Neel Natu <neel@freebsd.org>
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 ``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/param.h>
30#include <sys/types.h>
31#include <sys/mman.h>
32#include <sys/stat.h>
33
34#include <machine/vmm.h>
35
36#include <err.h>
37#include <errno.h>
38#include <fcntl.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43#include <stdbool.h>
44
45#include <vmmapi.h>
46
47#include "bhyverun.h"
48#include "bootrom.h"
49#include "debug.h"
50#include "mem.h"
51
52#define	BOOTROM_SIZE	(16 * 1024 * 1024)	/* 16 MB */
53
54/*
55 * ROM region is 16 MB at the top of 4GB ("low") memory.
56 *
57 * The size is limited so it doesn't encroach into reserved MMIO space (e.g.,
58 * APIC, HPET, MSI).
59 *
60 * It is allocated in page-multiple blocks on a first-come first-serve basis,
61 * from high to low, during initialization, and does not change at runtime.
62 */
63static char *romptr;	/* Pointer to userspace-mapped bootrom region. */
64static vm_paddr_t gpa_base;	/* GPA of low end of region. */
65static vm_paddr_t gpa_allocbot;	/* Low GPA of free region. */
66static vm_paddr_t gpa_alloctop;	/* High GPA, minus 1, of free region. */
67
68#define CFI_BCS_WRITE_BYTE      0x10
69#define CFI_BCS_CLEAR_STATUS    0x50
70#define CFI_BCS_READ_STATUS     0x70
71#define CFI_BCS_READ_ARRAY      0xff
72
73static struct bootrom_var_state {
74	uint8_t		*mmap;
75	uint64_t	gpa;
76	off_t		size;
77	uint8_t		cmd;
78} var = { NULL, 0, 0, CFI_BCS_READ_ARRAY };
79
80/*
81 * Emulate just those CFI basic commands that will convince EDK II
82 * that the Firmware Volume area is writable and persistent.
83 */
84static int
85bootrom_var_mem_handler(struct vcpu *vcpu __unused, int dir, uint64_t addr,
86    int size, uint64_t *val, void *arg1 __unused, long arg2 __unused)
87{
88	off_t offset;
89
90	offset = addr - var.gpa;
91	if (offset + size > var.size || offset < 0 || offset + size <= offset)
92		return (EINVAL);
93
94	if (dir == MEM_F_WRITE) {
95		switch (var.cmd) {
96		case CFI_BCS_WRITE_BYTE:
97			memcpy(var.mmap + offset, val, size);
98			var.cmd = CFI_BCS_READ_ARRAY;
99			break;
100		default:
101			var.cmd = *(uint8_t *)val;
102		}
103	} else {
104		switch (var.cmd) {
105		case CFI_BCS_CLEAR_STATUS:
106		case CFI_BCS_READ_STATUS:
107			memset(val, 0, size);
108			var.cmd = CFI_BCS_READ_ARRAY;
109			break;
110		default:
111			memcpy(val, var.mmap + offset, size);
112			break;
113		}
114	}
115	return (0);
116}
117
118void
119init_bootrom(struct vmctx *ctx)
120{
121	vm_paddr_t highmem;
122
123	romptr = vm_create_devmem(ctx, VM_BOOTROM, "bootrom", BOOTROM_SIZE);
124	if (romptr == MAP_FAILED)
125		err(4, "%s: vm_create_devmem", __func__);
126	highmem = vm_get_highmem_base(ctx);
127	gpa_base = highmem - BOOTROM_SIZE;
128	gpa_allocbot = gpa_base;
129	gpa_alloctop = highmem - 1;
130}
131
132int
133bootrom_alloc(struct vmctx *ctx, size_t len, int prot, int flags,
134    char **region_out, uint64_t *gpa_out)
135{
136	static const int bootrom_valid_flags = BOOTROM_ALLOC_TOP;
137
138	vm_paddr_t gpa;
139	vm_ooffset_t segoff;
140
141	if (flags & ~bootrom_valid_flags) {
142		warnx("%s: Invalid flags: %x", __func__,
143		    flags & ~bootrom_valid_flags);
144		return (EINVAL);
145	}
146	if (prot & ~_PROT_ALL) {
147		warnx("%s: Invalid protection: %x", __func__,
148		    prot & ~_PROT_ALL);
149		return (EINVAL);
150	}
151
152	if (len == 0 || len > BOOTROM_SIZE) {
153		warnx("ROM size %zu is invalid", len);
154		return (EINVAL);
155	}
156	if (len & PAGE_MASK) {
157		warnx("ROM size %zu is not a multiple of the page size",
158		    len);
159		return (EINVAL);
160	}
161
162	if (flags & BOOTROM_ALLOC_TOP) {
163		gpa = (gpa_alloctop - len) + 1;
164		if (gpa < gpa_allocbot) {
165			warnx("No room for %zu ROM in bootrom region", len);
166			return (ENOMEM);
167		}
168	} else {
169		gpa = gpa_allocbot;
170		if (gpa > (gpa_alloctop - len) + 1) {
171			warnx("No room for %zu ROM in bootrom region", len);
172			return (ENOMEM);
173		}
174	}
175
176	segoff = gpa - gpa_base;
177	if (vm_mmap_memseg(ctx, gpa, VM_BOOTROM, segoff, len, prot) != 0) {
178		int serrno = errno;
179		warn("%s: vm_mmap_mapseg", __func__);
180		return (serrno);
181	}
182
183	if (flags & BOOTROM_ALLOC_TOP)
184		gpa_alloctop = gpa - 1;
185	else
186		gpa_allocbot = gpa + len;
187
188	*region_out = romptr + segoff;
189	if (gpa_out != NULL)
190		*gpa_out = gpa;
191	return (0);
192}
193
194int
195bootrom_loadrom(struct vmctx *ctx, const nvlist_t *nvl)
196{
197	struct stat sbuf;
198	ssize_t rlen;
199	off_t rom_size, var_size, total_size;
200	char *ptr, *romfile;
201	int fd, varfd, i, rv;
202	const char *bootrom, *varfile;
203
204	rv = -1;
205	varfd = -1;
206
207	bootrom = get_config_value_node(nvl, "bootrom");
208	if (bootrom == NULL) {
209		return (-1);
210	}
211
212	/*
213	 * get_config_value_node may use a thread local buffer to return
214	 * variables. So, when we query the second variable, the first variable
215	 * might get overwritten. For that reason, the bootrom should be
216	 * duplicated.
217	 */
218	romfile = strdup(bootrom);
219	if (romfile == NULL) {
220		return (-1);
221	}
222
223	fd = open(romfile, O_RDONLY);
224	if (fd < 0) {
225		EPRINTLN("Error opening bootrom \"%s\": %s",
226		    romfile, strerror(errno));
227		goto done;
228	}
229
230	if (fstat(fd, &sbuf) < 0) {
231		EPRINTLN("Could not fstat bootrom file \"%s\": %s", romfile,
232		    strerror(errno));
233		goto done;
234	}
235
236	rom_size = sbuf.st_size;
237
238	varfile = get_config_value_node(nvl, "bootvars");
239	var_size = 0;
240	if (varfile != NULL) {
241		varfd = open(varfile, O_RDWR);
242		if (varfd < 0) {
243			EPRINTLN("Error opening bootrom variable file "
244			    "\"%s\": %s", varfile, strerror(errno));
245			goto done;
246		}
247
248		if (fstat(varfd, &sbuf) < 0) {
249			EPRINTLN(
250			    "Could not fstat bootrom variable file \"%s\": %s",
251			    varfile, strerror(errno));
252			goto done;
253		}
254
255		var_size = sbuf.st_size;
256	}
257
258	if (var_size > BOOTROM_SIZE ||
259	    (var_size != 0 && var_size < PAGE_SIZE)) {
260		EPRINTLN("Invalid bootrom variable size %ld",
261		    var_size);
262		goto done;
263	}
264
265	total_size = rom_size + var_size;
266
267	if (total_size > BOOTROM_SIZE) {
268		EPRINTLN("Invalid bootrom and variable aggregate size %ld",
269		    total_size);
270		goto done;
271	}
272
273	/* Map the bootrom into the guest address space */
274	if (bootrom_alloc(ctx, rom_size, PROT_READ | PROT_EXEC,
275	    BOOTROM_ALLOC_TOP, &ptr, NULL) != 0) {
276		goto done;
277	}
278
279	/* Read 'romfile' into the guest address space */
280	for (i = 0; i < rom_size / PAGE_SIZE; i++) {
281		rlen = read(fd, ptr + i * PAGE_SIZE, PAGE_SIZE);
282		if (rlen != PAGE_SIZE) {
283			EPRINTLN("Incomplete read of page %d of bootrom "
284			    "file %s: %ld bytes", i, romfile, rlen);
285			goto done;
286		}
287	}
288
289	if (varfd >= 0) {
290		var.mmap = mmap(NULL, var_size, PROT_READ | PROT_WRITE,
291		    MAP_SHARED, varfd, 0);
292		if (var.mmap == MAP_FAILED)
293			goto done;
294		var.size = var_size;
295		var.gpa = (gpa_alloctop - var_size) + 1;
296		gpa_alloctop = var.gpa - 1;
297		rv = register_mem(&(struct mem_range){
298		    .name = "bootrom variable",
299		    .flags = MEM_F_RW,
300		    .handler = bootrom_var_mem_handler,
301		    .base = var.gpa,
302		    .size = var.size,
303		});
304		if (rv != 0)
305			goto done;
306	}
307
308	rv = 0;
309done:
310	if (varfd >= 0)
311		close(varfd);
312	if (fd >= 0)
313		close(fd);
314	free(romfile);
315	return (rv);
316}
317