Laurent Vivier <lviv...@redhat.com> writes:
> As qemu_opts_parse_noisily() flattens the QAPI structures ("type" field
> of Netdev structure can collides with "type" field of SocketAddress),
> we introduce a way to bypass qemu_opts_parse_noisily() and use directly
> visit_type_Netdev() to parse the backend parameters.
>
> More details from Markus:
>
> qemu_init() passes the argument of -netdev, -nic, and -net to
> net_client_parse().
>
> net_client_parse() parses with qemu_opts_parse_noisily(), passing
> QemuOptsList qemu_netdev_opts for -netdev, qemu_nic_opts for -nic, and
> qemu_net_opts for -net. Their desc[] are all empty, which means any
> keys are accepted. The result of the parse (a QemuOpts) is stored in
> the QemuOptsList.
>
> Note that QemuOpts is flat by design. In some places, we layer non-flat
> on top using dotted keys convention, but not here.
>
> net_init_clients() iterates over the stored QemuOpts, and passes them to
> net_init_netdev(), net_param_nic(), or net_init_client(), respectively.
>
> These functions pass the QemuOpts to net_client_init(). They also do
> other things with the QemuOpts, which we can ignore here.
>
> net_client_init() uses the opts visitor to convert the (flat) QemOpts to
> a (non-flat) QAPI object Netdev. Netdev is also the argument of QMP
> command netdev_add.
>
> The opts visitor was an early attempt to support QAPI in
> (QemuOpts-based) CLI. It restricts QAPI types to a certain shape; see
> commit eb7ee2cbeb "qapi: introduce OptsVisitor".
>
> A more modern way to support QAPI is qobject_input_visitor_new_str().
> It uses keyval_parse() instead of QemuOpts for KEY=VALUE,... syntax, and
> it also supports JSON syntax. The former isn't quite as expressive as
> JSON, but it's a lot closer than QemuOpts + opts visitor.
>
> This commit paves the way to use of the modern way instead.
>
> Signed-off-by: Laurent Vivier <lviv...@redhat.com>
> ---
> include/net/net.h | 4 +++-
> net/net.c | 60 +++++++++++++++++++++++++++++++++++++++++++----
> softmmu/vl.c | 14 +++++------
> 3 files changed, 65 insertions(+), 13 deletions(-)
>
> diff --git a/include/net/net.h b/include/net/net.h
> index c53c64ac18c4..826e14a78734 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -214,7 +214,9 @@ extern NICInfo nd_table[MAX_NICS];
> extern const char *host_net_devices[];
>
> /* from net.c */
> -int net_client_parse(QemuOptsList *opts_list, const char *str);
> +bool netdev_is_modern(const char *optarg);
> +void netdev_parse_modern(const char *optarg);
> +void net_client_parse(QemuOptsList *opts_list, const char *str);
> void show_netdevs(void);
> void net_init_clients(void);
> void net_check_clients(void);
> diff --git a/net/net.c b/net/net.c
> index 15958f881776..531e6c5d2056 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -54,6 +54,7 @@
> #include "net/colo-compare.h"
> #include "net/filter.h"
> #include "qapi/string-output-visitor.h"
> +#include "qapi/qobject-input-visitor.h"
>
> /* Net bridge is currently not supported for W32. */
> #if !defined(_WIN32)
> @@ -63,6 +64,16 @@
> static VMChangeStateEntry *net_change_state_entry;
> static QTAILQ_HEAD(, NetClientState) net_clients;
>
> +typedef struct NetdevQueueEntry {
> + Netdev *nd;
> + Location loc;
> + QSIMPLEQ_ENTRY(NetdevQueueEntry) entry;
> +} NetdevQueueEntry;
> +
> +typedef QSIMPLEQ_HEAD(, NetdevQueueEntry) NetdevQueue;
> +
> +static NetdevQueue nd_queue = QSIMPLEQ_HEAD_INITIALIZER(nd_queue);
> +
> /***********************************************************/
> /* network device redirectors */
>
> @@ -1562,6 +1573,20 @@ out:
> return ret;
> }
>
> +static void netdev_init_modern(void)
> +{
> + while (!QSIMPLEQ_EMPTY(&nd_queue)) {
> + NetdevQueueEntry *nd = QSIMPLEQ_FIRST(&nd_queue);
> +
> + QSIMPLEQ_REMOVE_HEAD(&nd_queue, entry);
> + loc_push_restore(&nd->loc);
> + net_client_init1(nd->nd, true, &error_fatal);
> + loc_pop(&nd->loc);
> + qapi_free_Netdev(nd->nd);
> + g_free(nd);
> + }
> +}
> +
> void net_init_clients(void)
> {
> net_change_state_entry =
> @@ -1569,6 +1594,8 @@ void net_init_clients(void)
>
> QTAILQ_INIT(&net_clients);
>
> + netdev_init_modern();
> +
> qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL,
> &error_fatal);
>
> @@ -1579,13 +1606,38 @@ void net_init_clients(void)
> &error_fatal);
> }
>
> -int net_client_parse(QemuOptsList *opts_list, const char *optarg)
> +/*
> + * netdev_is_modern() returns true when the backend needs to bypass
> + * qemu_opts_parse_noisily()
> + */
Suggest
/*
* Does this -netdev argument use modern rather than traditional syntax?
* Modern syntax is to be parsed with netdev_parse_modern().
* Traditional syntax is to be parsed with net_client_parse().
*/
> +bool netdev_is_modern(const char *optarg)
> +{
> + return false;
> +}
> +
> +/*
> + * netdev_parse_modern() uses modern, more expressive syntax than
> + * net_client_parse(), supports only the netdev option.
Suggest "but supports" or "and supports".
Suggest "the -netdev option".
Should we mention the difference in storing of the result?
netdev_parse_modern() appends to @nd_queue, whereas net_client_parse()
appends to @qemu_netdev_opts.
> + */
> +void netdev_parse_modern(const char *optarg)
> +{
> + Visitor *v;
> + NetdevQueueEntry *nd;
> +
> + v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
> + nd = g_new(NetdevQueueEntry, 1);
> + visit_type_Netdev(v, NULL, &nd->nd, &error_fatal);
> + visit_free(v);
> + loc_save(&nd->loc);
> +
> + QSIMPLEQ_INSERT_TAIL(&nd_queue, nd, entry);
> +}
> +
> +void net_client_parse(QemuOptsList *opts_list, const char *optarg)
> {
> if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
> - return -1;
> + exit(1);
> }
> -
> - return 0;
> }
I'd put the change of net_client_parse() into its own patch.
>
> /* From FreeBSD */
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index c244e8afc4cc..f557e2d8cb8a 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -2794,21 +2794,19 @@ void qemu_init(int argc, char **argv, char **envp)
> break;
> case QEMU_OPTION_netdev:
> default_net = 0;
> - if (net_client_parse(qemu_find_opts("netdev"), optarg) ==
> -1) {
> - exit(1);
> + if (netdev_is_modern(optarg)) {
> + netdev_parse_modern(optarg);
> + } else {
> + net_client_parse(qemu_find_opts("netdev"), optarg);
> }
> break;
> case QEMU_OPTION_nic:
> default_net = 0;
> - if (net_client_parse(qemu_find_opts("nic"), optarg) == -1) {
> - exit(1);
> - }
> + net_client_parse(qemu_find_opts("nic"), optarg);
> break;
> case QEMU_OPTION_net:
> default_net = 0;
> - if (net_client_parse(qemu_find_opts("net"), optarg) == -1) {
> - exit(1);
> - }
> + net_client_parse(qemu_find_opts("net"), optarg);
> break;
> #ifdef CONFIG_LIBISCSI
> case QEMU_OPTION_iscsi:
