cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

xen_pt_load_rom.c (2882B)

      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 */
     16void *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 != -1) {
     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;
     82close_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}