os-posix: Provide new -runas <uid>:<gid> facility
This allows the caller to specify a uid and gid to use, even if there
is no corresponding password entry. This will be useful in certain
Xen configurations.
We don't support just -runas <uid> because: (i) deprivileging without
calling setgroups would be ineffective (ii) given only a uid we don't
know what gid we ought to use (since uids may eppear in multiple
passwd file entries with different gids).
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Daniel P. Berrange <berrange@redhat.com>
CC: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
diff --git a/qemu-options.hx b/qemu-options.hx
index ca4e412..5fbf966 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3765,7 +3765,8 @@
#ifndef _WIN32
DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
- "-runas user change to user id user just before starting the VM\n",
+ "-runas user change to user id user just before starting the VM\n" \
+ " user can be numeric uid:gid instead\n",
QEMU_ARCH_ALL)
#endif
STEXI
