softmmu/vl: Allow -fw_cfg 'gen_id' option to use the 'etc/' namespace

Names of user-provided fw_cfg items are supposed to start
with "opt/". However FW_CFG_DATA_GENERATOR items are generated
by QEMU, so allow the "etc/" namespace in this specific case.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200623172726.21040-5-philmd@redhat.com>
This commit is contained in:
Philippe Mathieu-Daudé 2020-05-19 19:17:09 +02:00
parent 6552d87c48
commit f7d8afb16d
2 changed files with 11 additions and 1 deletions

View File

@ -258,4 +258,8 @@ Prefix "opt/org.qemu/" is reserved for QEMU itself.
Use of names not beginning with "opt/" is potentially dangerous and
entirely unsupported. QEMU will warn if you try.
Use of names not beginning with "opt/" is tolerated with 'gen_id' (that
is, the warning is suppressed), but you must know exactly what you're
doing.
All externally provided fw_cfg items are read-only to the guest.

View File

@ -2049,7 +2049,13 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
FW_CFG_MAX_FILE_PATH - 1);
return -1;
}
if (strncmp(name, "opt/", 4) != 0) {
if (nonempty_str(gen_id)) {
/*
* In this particular case where the content is populated
* internally, the "etc/" namespace protection is relaxed,
* so do not emit a warning.
*/
} else if (strncmp(name, "opt/", 4) != 0) {
warn_report("externally provided fw_cfg item names "
"should be prefixed with \"opt/\"");
}