Hi all,
via a quick hack, I realized a power-saving optimization for a VM that
serves sporadic network requests:
diff --git a/net/slirp.c b/net/slirp.c
index 120eef6122..f6b0ddc846 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -40,6 +40,7 @@
#include "qemu/sockets.h"
#include <libslirp.h>
#include "chardev/char-fe.h"
+#include "system/runstate.h"
#include "system/system.h"
#include "qemu/cutils.h"
#include "qapi/error.h"
@@ -120,6 +121,8 @@ static ssize_t net_slirp_send_packet(const void *pkt,
size_t pkt_len,
uint8_t min_pkt[ETH_ZLEN];
size_t min_pktsz = sizeof(min_pkt);
+ qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
+
if (net_peer_needs_padding(&s->nc)) {
if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pkt_len)) {
pkt = min_pkt;
This plus suspend-to-ram inside the VM after some idle time gives a
nice workload reduction for the host. But it is a hack, just working too
well to make we wonder if there could be a way to get this modeled also
without a patch.
Do I rather have to write a proxy service that hooks into the traffic
targeting the VM and performs the wakeup via QMP? Or is there a chance
to get something similar to serial [1] also into the network path?
Ideas would be welcome.
TIA!
Jan
[1]
https://gitlab.com/qemu-project/qemu/-/commit/9826fd597df59a8bac7beafd192e4baad790c31a
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Siemens AG, Foundational Technologies
Linux Expert Center
