Re: [RFC PATCH v1 02/26] char-socket: allow vsock parameters (cid, port)

[Marc-André Lureau]

Hi

On Wed, Apr 15, 2020 at 3:00 AM Adalbert Lazăr <address@hidden> wrote:
>
> The introspection tool can run in a separate VM and the introspected
> VM will establish a connection using a virtual socket.
>
> CC: "Marc-André Lureau" <address@hidden>
> CC: Paolo Bonzini <address@hidden>
> Signed-off-by: Adalbert Lazăr <address@hidden>

We should also add QMP support.

Please add some tests in tests/test-char.c.

> ---
>  chardev/char-socket.c | 27 ++++++++++++++++++++++++---
>  chardev/char.c        |  3 +++
>  2 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> index bd966aace1..9b2deb0125 100644
> --- a/chardev/char-socket.c
> +++ b/chardev/char-socket.c
> @@ -23,6 +23,11 @@
>   */
>
>  #include "qemu/osdep.h"
> +
> +#ifdef CONFIG_AF_VSOCK
> +#include <linux/vm_sockets.h>
> +#endif /* CONFIG_AF_VSOCK */
> +
>  #include "chardev/char.h"
>  #include "io/channel-socket.h"
>  #include "io/channel-tls.h"
> @@ -590,6 +595,14 @@ static char *qemu_chr_compute_filename(SocketChardev *s)
>                                 s->is_listen ? ",server" : "",
>                                 left, phost, right, pserv);
>
> +#ifdef CONFIG_AF_VSOCK
> +    case AF_VSOCK:
> +        return g_strdup_printf("vsock:%d:%d%s",
> +                               ((struct sockaddr_vm *)(ss))->svm_cid,
> +                               ((struct sockaddr_vm *)(ss))->svm_port,
> +                               s->is_listen ? ",server" : "");
> +#endif
> +
>      default:
>          return g_strdup_printf("unknown");
>      }
> @@ -1378,18 +1391,19 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
> ChardevBackend *backend,
>  {
>      const char *path = qemu_opt_get(opts, "path");
>      const char *host = qemu_opt_get(opts, "host");
> +    const char *cid  = qemu_opt_get(opts, "cid");
>      const char *port = qemu_opt_get(opts, "port");
>      const char *fd = qemu_opt_get(opts, "fd");
>      SocketAddressLegacy *addr;
>      ChardevSocket *sock;
>
> -    if ((!!path + !!fd + !!host) != 1) {
> +    if ((!!path + !!fd + !!host + !!cid) != 1) {
>          error_setg(errp,
> -                   "Exactly one of 'path', 'fd' or 'host' required");
> +                   "Exactly one of 'path', 'fd', 'cid' or 'host' required");
>          return;
>      }
>
> -    if (host && !port) {
> +    if ((host || cid) && !port) {
>          error_setg(errp, "chardev: socket: no port given");
>          return;
>      }
> @@ -1444,6 +1458,13 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
> ChardevBackend *backend,
>              .has_ipv6 = qemu_opt_get(opts, "ipv6"),
>              .ipv6 = qemu_opt_get_bool(opts, "ipv6", 0),
>          };
> +    } else if (cid) {
> +        addr->type = SOCKET_ADDRESS_LEGACY_KIND_VSOCK;
> +        addr->u.vsock.data = g_new0(VsockSocketAddress, 1);
> +        *addr->u.vsock.data = (VsockSocketAddress) {
> +            .cid  = g_strdup(cid),
> +            .port = g_strdup(port),
> +        };
>      } else if (fd) {
>          addr->type = SOCKET_ADDRESS_LEGACY_KIND_FD;
>          addr->u.fd.data = g_new(String, 1);
> diff --git a/chardev/char.c b/chardev/char.c
> index e77564060d..39e36ceb97 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -852,6 +852,9 @@ QemuOptsList qemu_chardev_opts = {
>          },{
>              .name = "host",
>              .type = QEMU_OPT_STRING,
> +        },{
> +            .name = "cid",
> +            .type = QEMU_OPT_STRING,
>          },{
>              .name = "port",
>              .type = QEMU_OPT_STRING,
>


-- 
Marc-André Lureau