From 7d9fa19ec43b05e82443f49eee24d78dd1a3565c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Marczykowski-G=C3=B3recki?= Date: Sat, 16 Jul 2016 01:47:56 +0200 Subject: [PATCH] libxl: trigger attach events for devices attached before xl devd startup MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When this daemon is started after creating backend device, that device will not be configured. Racy situation: 1. driver domain is started 2. frontend domain is started (just after kicking driver domain off) 3. device in frontend domain is connected to the backend (as specified in frontend domain configuration) 4. xl devd is started in driver domain End result is that backend device in driver domain is not configured (like network interface is not enabled), so the device doesn't work. Fix this by artifically triggering events for devices already present in xenstore before xl devd is started. Do this only after xenstore watch is already registered, and only for devices not already initialized (in XenbusStateInitWait state). Cc: Ian Jackson Cc: Wei Liu Signed-off-by: Marek Marczykowski-Górecki Acked-by: Wei Liu --- tools/libxl/libxl.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 2cf745153f..b5f90844c6 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -4658,6 +4658,12 @@ int libxl_device_events_handler(libxl_ctx *ctx, uint32_t domid; libxl__ddomain ddomain; char *be_path; + char **kinds = NULL, **domains = NULL, **devs = NULL; + const char *sstate; + char *state_path; + int state; + unsigned int nkinds, ndomains, ndevs; + int i, j, k; ddomain.ao = ao; LIBXL_SLIST_INIT(&ddomain.guests); @@ -4677,6 +4683,33 @@ int libxl_device_events_handler(libxl_ctx *ctx, be_path); if (rc) goto out; + kinds = libxl__xs_directory(gc, XBT_NULL, be_path, &nkinds); + if (kinds) { + for (i = 0; i < nkinds; i++) { + domains = libxl__xs_directory(gc, XBT_NULL, + GCSPRINTF("%s/%s", be_path, kinds[i]), &ndomains); + if (!domains) + continue; + for (j = 0; j < ndomains; j++) { + devs = libxl__xs_directory(gc, XBT_NULL, + GCSPRINTF("%s/%s/%s", be_path, kinds[i], domains[j]), &ndevs); + if (!devs) + continue; + for (k = 0; k < ndevs; k++) { + state_path = GCSPRINTF("%s/%s/%s/%s/state", + be_path, kinds[i], domains[j], devs[k]); + rc = libxl__xs_read_checked(gc, XBT_NULL, state_path, &sstate); + if (rc || !sstate) + continue; + state = atoi(sstate); + if (state == XenbusStateInitWait) + backend_watch_callback(egc, &ddomain.watch, + be_path, state_path); + } + } + } + } + return AO_INPROGRESS; out: -- 2.30.2