qemu-config: Add new -add-fd command line option
This option can be used for passing file descriptors on the
command line. It mirrors the existing add-fd QMP command which
allows an fd to be passed to QEMU via SCM_RIGHTS and added to an
fd set.
This can be combined with commands such as -drive to link file
descriptors in an fd set to a drive:
qemu-kvm -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
-drive file=/dev/fdset/2,index=0,media=disk
This example adds dups of fds 3 and 4, and the accompanying opaque
strings to the fd set with ID=2. qemu_open() already knows how
to handle a filename of this format. qemu_open() searches the
corresponding fd set for an fd and when it finds a match, QEMU
goes on to use a dup of that fd just like it would have used an
fd that it opened itself.
Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qemu-config.c b/qemu-config.c
index cd1ec21..601237d 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -653,6 +653,27 @@
},
};
+static QemuOptsList qemu_add_fd_opts = {
+ .name = "add-fd",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_add_fd_opts.head),
+ .desc = {
+ {
+ .name = "fd",
+ .type = QEMU_OPT_NUMBER,
+ .help = "file descriptor of which a duplicate is added to fd set",
+ },{
+ .name = "set",
+ .type = QEMU_OPT_NUMBER,
+ .help = "ID of the fd set to add fd to",
+ },{
+ .name = "opaque",
+ .type = QEMU_OPT_STRING,
+ .help = "free-form string used to describe fd",
+ },
+ { /* end of list */ }
+ },
+};
+
static QemuOptsList *vm_config_groups[32] = {
&qemu_drive_opts,
&qemu_chardev_opts,
@@ -669,6 +690,7 @@
&qemu_boot_opts,
&qemu_iscsi_opts,
&qemu_sandbox_opts,
+ &qemu_add_fd_opts,
NULL,
};