xref: /openbmc/qemu/hw/xen/xen_pt_load_rom.c (revision 05caa062)
1 /*
2  * This is splited from hw/i386/kvm/pci-assign.c
3  */
4 #include "qemu/osdep.h"
5 #include "qapi/error.h"
6 #include "qemu/error-report.h"
7 #include "hw/loader.h"
8 #include "hw/pci/pci.h"
9 #include "xen_pt.h"
10 
11 /*
12  * Scan the assigned devices for the devices that have an option ROM, and then
13  * load the corresponding ROM data to RAM. If an error occurs while loading an
14  * option ROM, we just ignore that option ROM and continue with the next one.
15  */
16 void *pci_assign_dev_load_option_rom(PCIDevice *dev,
17                                      int *size, unsigned int domain,
18                                      unsigned int bus, unsigned int slot,
19                                      unsigned int function)
20 {
21     char name[32], rom_file[64];
22     FILE *fp;
23     uint8_t val;
24     struct stat st;
25     void *ptr = NULL;
26     Object *owner = OBJECT(dev);
27 
28     /* If loading ROM from file, pci handles it */
29     if (dev->romfile || !dev->rom_bar) {
30         return NULL;
31     }
32 
33     snprintf(rom_file, sizeof(rom_file),
34              "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/rom",
35              domain, bus, slot, function);
36 
37     /* Write "1" to the ROM file to enable it */
38     fp = fopen(rom_file, "r+");
39     if (fp == NULL) {
40         if (errno != ENOENT) {
41             error_report("pci-assign: Cannot open %s: %s", rom_file, strerror(errno));
42         }
43         return NULL;
44     }
45     if (fstat(fileno(fp), &st) == -1) {
46         error_report("pci-assign: Cannot stat %s: %s", rom_file, strerror(errno));
47         goto close_rom;
48     }
49 
50     val = 1;
51     if (fwrite(&val, 1, 1, fp) != 1) {
52         goto close_rom;
53     }
54     fseek(fp, 0, SEEK_SET);
55 
56     if (dev->romsize != UINT_MAX) {
57         if (st.st_size > dev->romsize) {
58             error_report("ROM BAR \"%s\" (%ld bytes) is too large for ROM size %u",
59                          rom_file, (long) st.st_size, dev->romsize);
60             goto close_rom;
61         }
62     } else {
63         dev->romsize = st.st_size;
64     }
65 
66     snprintf(name, sizeof(name), "%s.rom", object_get_typename(owner));
67     memory_region_init_ram(&dev->rom, owner, name, dev->romsize, &error_abort);
68     ptr = memory_region_get_ram_ptr(&dev->rom);
69     memset(ptr, 0xff, dev->romsize);
70 
71     if (!fread(ptr, 1, st.st_size, fp)) {
72         error_report("pci-assign: Cannot read from host %s", rom_file);
73         error_printf("Device option ROM contents are probably invalid "
74                      "(check dmesg).\nSkip option ROM probe with rombar=0, "
75                      "or load from file with romfile=\n");
76         goto close_rom;
77     }
78 
79     pci_register_bar(dev, PCI_ROM_SLOT, 0, &dev->rom);
80     dev->has_rom = true;
81     *size = st.st_size;
82 close_rom:
83     /* Write "0" to disable ROM */
84     fseek(fp, 0, SEEK_SET);
85     val = 0;
86     if (!fwrite(&val, 1, 1, fp)) {
87         XEN_PT_WARN(dev, "%s\n", "Failed to disable pci-sysfs rom file");
88     }
89     fclose(fp);
90 
91     return ptr;
92 }
93