| Message ID | 1468626476-3072-1-git-send-email-marmarek@invisiblethingslab.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Jul 16, 2016 at 01:47:56AM +0200, Marek Marczykowski-Górecki wrote: > 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 <ian.jackson@eu.citrix.com> > Cc: Wei Liu <wei.liu2@citrix.com> > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Acked-by: Wei Liu <wei.liu2@citrix.com>
On Mon, Jul 18, 2016 at 04:31:30PM +0100, Wei Liu wrote: > On Sat, Jul 16, 2016 at 01:47:56AM +0200, Marek Marczykowski-Górecki wrote: > > 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 <ian.jackson@eu.citrix.com> > > Cc: Wei Liu <wei.liu2@citrix.com> > > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > Acked-by: Wei Liu <wei.liu2@citrix.com> Queued. Thanks.
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 1c81239..b69466f 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -4743,6 +4743,12 @@ 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); @@ -4762,6 +4768,33 @@ 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:
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 <ian.jackson@eu.citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> --- Changes since v2: - check for sstate being NULL - minor indentation tools/libxl/libxl.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)