[0/2] util/qemu-sockets: Introduce configurable TCP keep-alive idle period

Message

Juraj Marcin March 3, 2025, 2:33 p.m. UTC

This series extends the work introduced by commit aec21d3175 ("qapi: Add
InetSocketAddress member keep-alive") [1]

First, it allows the use of the keep-alive flag for server-side sockets.
Then it introduces a new keep-alive-idle-period setting, which changes
the TCP_KEEPIDLE socket option on platforms that support it (this option
is found in Linux, BSD, and Win32 documentations).

By default, the value of keep-alive-idle-period is 0, which means no
custom socket option value is set.

This is useful, for example, for live migration. In case there is no
traffic from the destination to the source machine during postcopy, the
destination cannot detect a failed connection due to a lack of
non-acknowledged packets and stays in the postcopy-active state until
paused by the management of the QEMU instance.

[1]: https://lore.kernel.org/all/[e-mail]/

Juraj Marcin (2):
  util/qemu-sockets: Add support for keep-alive flag to passive sockets
  utils/qemu-sockets: Introduce keep-alive-idle-period inet socket
    option

 io/dns-resolver.c   |  6 +++++
 meson.build         |  2 ++
 qapi/sockets.json   |  9 +++++--
 util/qemu-sockets.c | 58 ++++++++++++++++++++++++++++++++++++++++-----
 4 files changed, 67 insertions(+), 8 deletions(-)