| Message ID | 20250303143312.640909-3-jmarcin@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | util/qemu-sockets: Introduce configurable TCP keep-alive idle period | expand |
On 03.03.25 17:33, Juraj Marcin wrote: > The default idle period for TCP connection could be even 2 hours. > However, in some cases, the application needs to be aware of a > connection issue much sooner. > > This is the case, for example, for postcopy live migration. If there is > no traffic from the migration destination guest (server-side) to the > migration source guest (client-side), the destination keeps waiting for > pages indefinitely and does not switch to the postcopy-paused state. > This can happen, for example, if the destination QEMU instance is > started with '-S' command line option and the machine is not started yet > or if the machine is idle and produces no new page faults for > not-yet-migrated pages. > > This patch introduces a new inet socket parameter on platforms where > TCP_KEEPIDLE is defined and passes the configured value to the > TCP_KEEPIDLE socket option when a client-side or server-side socket is > created. > > The default value is 0, which means system configuration is used, and no > custom value is set. > > Signed-off-by: Juraj Marcin <jmarcin@redhat.com> > --- > io/dns-resolver.c | 4 ++++ > meson.build | 2 ++ > qapi/sockets.json | 5 +++++ > util/qemu-sockets.c | 39 +++++++++++++++++++++++++++++++++++++++ > 4 files changed, 50 insertions(+) > > diff --git a/io/dns-resolver.c b/io/dns-resolver.c > index ee7403b65b..03c59673f0 100644 > --- a/io/dns-resolver.c > +++ b/io/dns-resolver.c > @@ -128,6 +128,10 @@ static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver, > #endif > .has_keep_alive = iaddr->has_keep_alive, > .keep_alive = iaddr->keep_alive, > +#ifdef HAVE_TCP_KEEPIDLE > + .has_keep_alive_idle_period = iaddr->has_keep_alive_idle_period, > + .keep_alive_idle_period = iaddr->keep_alive_idle_period, > +#endif > }; > > (*addrs)[i] = newaddr; > diff --git a/meson.build b/meson.build > index 0ee79c664d..ca726f317f 100644 > --- a/meson.build > +++ b/meson.build > @@ -2724,6 +2724,8 @@ config_host_data.set('HAVE_OPTRESET', > cc.has_header_symbol('getopt.h', 'optreset')) > config_host_data.set('HAVE_IPPROTO_MPTCP', > cc.has_header_symbol('netinet/in.h', 'IPPROTO_MPTCP')) > +config_host_data.set('HAVE_TCP_KEEPIDLE', > + cc.has_header_symbol('netinet/tcp.h', 'TCP_KEEPIDLE')) > > # has_member > config_host_data.set('HAVE_SIGEV_NOTIFY_THREAD_ID', > diff --git a/qapi/sockets.json b/qapi/sockets.json > index eb50f64e3a..ddd82b1e66 100644 > --- a/qapi/sockets.json > +++ b/qapi/sockets.json > @@ -59,6 +59,10 @@ > # @keep-alive: enable keep-alive when connecting to/listening on this socket. > # (Since 4.2, not supported for listening sockets until 10.0) > # > +# @keep-alive-idle-period: time in seconds the connection needs to be idle > +# before sending a keepalive packet. Only supported for TCP sockets on > +# systems where TCP_KEEPIDLE socket option is defined. (Since 10.0) > +# > # @mptcp: enable multi-path TCP. (Since 6.1) > # > # Since: 1.3 > @@ -71,6 +75,7 @@ > '*ipv4': 'bool', > '*ipv6': 'bool', > '*keep-alive': 'bool', > + '*keep-alive-idle-period': { 'type': 'uint32', 'if': 'HAVE_TCP_KEEPIDLE' }, > '*mptcp': { 'type': 'bool', 'if': 'HAVE_IPPROTO_MPTCP' } } } > > ## > diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c > index c30e4ac2ce..edcda846ef 100644 > --- a/util/qemu-sockets.c > +++ b/util/qemu-sockets.c > @@ -349,6 +349,18 @@ listen_ok: > slisten = -1; > goto exit; > } > +#ifdef HAVE_TCP_KEEPIDLE > + if (saddr->has_keep_alive_idle_period && saddr->keep_alive_idle_period) { > + int keepidle = saddr->has_keep_alive_idle_period; > + ret = setsockopt(slisten, IPPROTO_TCP, TCP_KEEPIDLE, &keepidle, sizeof(keepidle)); > + if (ret < 0) { > + error_setg_errno(errp, errno, "Unable to set TCP_KEEPIDLE"); > + close(slisten); > + slisten = -1; > + goto exit; > + } > + } > +#endif > } > exit: > freeaddrinfo(res); > @@ -492,6 +504,17 @@ int inet_connect_saddr(InetSocketAddress *saddr, Error **errp) > close(sock); > return -1; > } > +#ifdef HAVE_TCP_KEEPIDLE > + if (saddr->has_keep_alive_idle_period && saddr->keep_alive_idle_period) { > + int keepidle = saddr->keep_alive_idle_period; > + ret = setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE, &keepidle, sizeof(keepidle)); > + if (ret < 0) { > + error_setg_errno(errp, errno, "Unsable to set TCP_KEEPIDLE"); > + close(sock); > + return -1; > + } > + } > +#endif > } Looks like we need some inet_setsockopt(*saddr) {}, which set both options and called from both client and server sockets, to avoid duplication. > > return sock; > @@ -698,6 +721,22 @@ int inet_parse(InetSocketAddress *addr, const char *str, Error **errp) > } > addr->has_keep_alive = true; > } > +#ifdef HAVE_TCP_KEEPIDLE > + begin = strstr(optstr, ",keep-alive-idle-period="); > + if (begin) { > + begin += strlen(",keep-alive-idle-period="); > + if (sscanf(begin, "%" PRIu32 "%n", &addr->keep_alive_idle_period, &pos) != 1 || > + (begin[pos] != '\0' && begin[pos] != ',')) { > + error_setg(errp, "error parsing keep-alive-idle-period argument"); > + return -1; > + } > + if (addr->keep_alive_idle_period > INT_MAX) { > + error_setg(errp, "keep-alive-idle-period value is too large"); > + return -1; > + } > + addr->has_keep_alive_idle_period = true; > + } > +#endif > #ifdef HAVE_IPPROTO_MPTCP > begin = strstr(optstr, ",mptcp"); > if (begin) {
diff --git a/io/dns-resolver.c b/io/dns-resolver.c index ee7403b65b..03c59673f0 100644 --- a/io/dns-resolver.c +++ b/io/dns-resolver.c @@ -128,6 +128,10 @@ static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver, #endif .has_keep_alive = iaddr->has_keep_alive, .keep_alive = iaddr->keep_alive, +#ifdef HAVE_TCP_KEEPIDLE + .has_keep_alive_idle_period = iaddr->has_keep_alive_idle_period, + .keep_alive_idle_period = iaddr->keep_alive_idle_period, +#endif }; (*addrs)[i] = newaddr; diff --git a/meson.build b/meson.build index 0ee79c664d..ca726f317f 100644 --- a/meson.build +++ b/meson.build @@ -2724,6 +2724,8 @@ config_host_data.set('HAVE_OPTRESET', cc.has_header_symbol('getopt.h', 'optreset')) config_host_data.set('HAVE_IPPROTO_MPTCP', cc.has_header_symbol('netinet/in.h', 'IPPROTO_MPTCP')) +config_host_data.set('HAVE_TCP_KEEPIDLE', + cc.has_header_symbol('netinet/tcp.h', 'TCP_KEEPIDLE')) # has_member config_host_data.set('HAVE_SIGEV_NOTIFY_THREAD_ID', diff --git a/qapi/sockets.json b/qapi/sockets.json index eb50f64e3a..ddd82b1e66 100644 --- a/qapi/sockets.json +++ b/qapi/sockets.json @@ -59,6 +59,10 @@ # @keep-alive: enable keep-alive when connecting to/listening on this socket. # (Since 4.2, not supported for listening sockets until 10.0) # +# @keep-alive-idle-period: time in seconds the connection needs to be idle +# before sending a keepalive packet. Only supported for TCP sockets on +# systems where TCP_KEEPIDLE socket option is defined. (Since 10.0) +# # @mptcp: enable multi-path TCP. (Since 6.1) # # Since: 1.3 @@ -71,6 +75,7 @@ '*ipv4': 'bool', '*ipv6': 'bool', '*keep-alive': 'bool', + '*keep-alive-idle-period': { 'type': 'uint32', 'if': 'HAVE_TCP_KEEPIDLE' }, '*mptcp': { 'type': 'bool', 'if': 'HAVE_IPPROTO_MPTCP' } } } ## diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c index c30e4ac2ce..edcda846ef 100644 --- a/util/qemu-sockets.c +++ b/util/qemu-sockets.c @@ -349,6 +349,18 @@ listen_ok: slisten = -1; goto exit; } +#ifdef HAVE_TCP_KEEPIDLE + if (saddr->has_keep_alive_idle_period && saddr->keep_alive_idle_period) { + int keepidle = saddr->has_keep_alive_idle_period; + ret = setsockopt(slisten, IPPROTO_TCP, TCP_KEEPIDLE, &keepidle, sizeof(keepidle)); + if (ret < 0) { + error_setg_errno(errp, errno, "Unable to set TCP_KEEPIDLE"); + close(slisten); + slisten = -1; + goto exit; + } + } +#endif } exit: freeaddrinfo(res); @@ -492,6 +504,17 @@ int inet_connect_saddr(InetSocketAddress *saddr, Error **errp) close(sock); return -1; } +#ifdef HAVE_TCP_KEEPIDLE + if (saddr->has_keep_alive_idle_period && saddr->keep_alive_idle_period) { + int keepidle = saddr->keep_alive_idle_period; + ret = setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE, &keepidle, sizeof(keepidle)); + if (ret < 0) { + error_setg_errno(errp, errno, "Unsable to set TCP_KEEPIDLE"); + close(sock); + return -1; + } + } +#endif } return sock; @@ -698,6 +721,22 @@ int inet_parse(InetSocketAddress *addr, const char *str, Error **errp) } addr->has_keep_alive = true; } +#ifdef HAVE_TCP_KEEPIDLE + begin = strstr(optstr, ",keep-alive-idle-period="); + if (begin) { + begin += strlen(",keep-alive-idle-period="); + if (sscanf(begin, "%" PRIu32 "%n", &addr->keep_alive_idle_period, &pos) != 1 || + (begin[pos] != '\0' && begin[pos] != ',')) { + error_setg(errp, "error parsing keep-alive-idle-period argument"); + return -1; + } + if (addr->keep_alive_idle_period > INT_MAX) { + error_setg(errp, "keep-alive-idle-period value is too large"); + return -1; + } + addr->has_keep_alive_idle_period = true; + } +#endif #ifdef HAVE_IPPROTO_MPTCP begin = strstr(optstr, ",mptcp"); if (begin) {
The default idle period for TCP connection could be even 2 hours. However, in some cases, the application needs to be aware of a connection issue much sooner. This is the case, for example, for postcopy live migration. If there is no traffic from the migration destination guest (server-side) to the migration source guest (client-side), the destination keeps waiting for pages indefinitely and does not switch to the postcopy-paused state. This can happen, for example, if the destination QEMU instance is started with '-S' command line option and the machine is not started yet or if the machine is idle and produces no new page faults for not-yet-migrated pages. This patch introduces a new inet socket parameter on platforms where TCP_KEEPIDLE is defined and passes the configured value to the TCP_KEEPIDLE socket option when a client-side or server-side socket is created. The default value is 0, which means system configuration is used, and no custom value is set. Signed-off-by: Juraj Marcin <jmarcin@redhat.com> --- io/dns-resolver.c | 4 ++++ meson.build | 2 ++ qapi/sockets.json | 5 +++++ util/qemu-sockets.c | 39 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 50 insertions(+)