diff options
author | Gabriel L. Somlo <somlo@cmu.edu> | 2015-04-29 11:21:53 -0400 |
---|---|---|
committer | Gerd Hoffmann <kraxel@redhat.com> | 2015-06-10 08:06:46 +0200 |
commit | 81b2b81062612ebeac4cd5333a3b15c7d79a5a3d (patch) | |
tree | c505eeb49687c998e3f536e8e7fe0fbfbf5303b1 | |
parent | 0eb973f91521c6bcb6399d25327711d083f6eb10 (diff) |
fw_cfg: insert fw_cfg file blobs via qemu cmdline
Allow user supplied files to be inserted into the fw_cfg
device before starting the guest. Since fw_cfg_add_file()
already disallows duplicate fw_cfg file names, qemu will
exit with an error message if the user supplies multiple
blobs with the same fw_cfg file name, or if a blob name
collides with a fw_cfg name programmatically added from
within the QEMU source code. A warning message will be
printed if the fw_cfg item name does not begin with the
prefix "opt/", which is recommended for external, user
provided blobs.
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
-rw-r--r-- | docs/specs/fw_cfg.txt | 21 | ||||
-rw-r--r-- | qemu-options.hx | 11 | ||||
-rw-r--r-- | vl.c | 63 |
3 files changed, 95 insertions, 0 deletions
diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 6accd924bd..74351dd18f 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -203,3 +203,24 @@ completes fully overwriting the item's data. NOTE: This function is deprecated, and will be completely removed starting with QEMU v2.4. + +== Externally Provided Items == + +As of v2.4, "file" fw_cfg items (i.e., items with selector keys above +FW_CFG_FILE_FIRST, and with a corresponding entry in the fw_cfg file +directory structure) may be inserted via the QEMU command line, using +the following syntax: + + -fw_cfg [name=]<item_name>,file=<path> + +where <item_name> is the fw_cfg item name, and <path> is the location +on the host file system of a file containing the data to be inserted. + +NOTE: Users *SHOULD* choose item names beginning with the prefix "opt/" +when using the "-fw_cfg" command line option, to avoid conflicting with +item names used internally by QEMU. For instance: + + -fw_cfg name=opt/my_item_name,file=./my_blob.bin + +Similarly, QEMU developers *SHOULD NOT* use item names prefixed with +"opt/" when inserting items programmatically, e.g. via fw_cfg_add_file(). diff --git a/qemu-options.hx b/qemu-options.hx index 4be98f71df..1d281f6818 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2686,6 +2686,17 @@ STEXI @table @option ETEXI +DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, + "-fw_cfg [name=]<name>,file=<file>\n" + " add named fw_cfg entry from file\n", + QEMU_ARCH_ALL) +STEXI +@item -fw_cfg [name=]@var{name},file=@var{file} +@findex -fw_cfg +Add named fw_cfg entry from file. @var{name} determines the name of +the entry in the fw_cfg file directory exposed to the guest. +ETEXI + DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ "-serial dev redirect the serial port to char device 'dev'\n", QEMU_ARCH_ALL) @@ -492,6 +492,25 @@ static QemuOptsList qemu_semihosting_config_opts = { }, }; +static QemuOptsList qemu_fw_cfg_opts = { + .name = "fw_cfg", + .implied_opt_name = "name", + .head = QTAILQ_HEAD_INITIALIZER(qemu_fw_cfg_opts.head), + .desc = { + { + .name = "name", + .type = QEMU_OPT_STRING, + .help = "Sets the fw_cfg name of the blob to be inserted", + }, { + .name = "file", + .type = QEMU_OPT_STRING, + .help = "Sets the name of the file from which\n" + "the fw_cfg blob will be loaded", + }, + { /* end of list */ } + }, +}; + /** * Get machine options * @@ -2127,6 +2146,38 @@ char *qemu_find_file(int type, const char *name) return NULL; } +static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) +{ + gchar *buf; + size_t size; + const char *name, *file; + + if (opaque == NULL) { + error_report("fw_cfg device not available"); + return -1; + } + name = qemu_opt_get(opts, "name"); + file = qemu_opt_get(opts, "file"); + if (name == NULL || *name == '\0' || file == NULL || *file == '\0') { + error_report("invalid argument value"); + return -1; + } + if (strlen(name) > FW_CFG_MAX_FILE_PATH - 1) { + error_report("name too long (max. %d char)", FW_CFG_MAX_FILE_PATH - 1); + return -1; + } + if (strncmp(name, "opt/", 4) != 0) { + error_report("WARNING: externally provided fw_cfg item names " + "should be prefixed with \"opt/\"!"); + } + if (!g_file_get_contents(file, &buf, &size, NULL)) { + error_report("can't load %s", file); + return -1; + } + fw_cfg_add_file((FWCfgState *)opaque, name, buf, size); + return 0; +} + static int device_help_func(void *opaque, QemuOpts *opts, Error **errp) { return qdev_device_help(opts); @@ -2822,6 +2873,7 @@ int main(int argc, char **argv, char **envp) qemu_add_opts(&qemu_numa_opts); qemu_add_opts(&qemu_icount_opts); qemu_add_opts(&qemu_semihosting_config_opts); + qemu_add_opts(&qemu_fw_cfg_opts); runstate_init(); @@ -3438,6 +3490,12 @@ int main(int argc, char **argv, char **envp) } do_smbios_option(opts); break; + case QEMU_OPTION_fwcfg: + opts = qemu_opts_parse(qemu_find_opts("fw_cfg"), optarg, 1); + if (opts == NULL) { + exit(1); + } + break; case QEMU_OPTION_enable_kvm: olist = qemu_find_opts("machine"); qemu_opts_parse(olist, "accel=kvm", 0); @@ -4274,6 +4332,11 @@ int main(int argc, char **argv, char **envp) numa_post_machine_init(); + if (qemu_opts_foreach(qemu_find_opts("fw_cfg"), + parse_fw_cfg, fw_cfg_find(), NULL) != 0) { + exit(1); + } + /* init USB devices */ if (usb_enabled()) { if (foreach_device_config(DEV_USB, usb_parse) < 0) |