From: "Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>
To: xen-devel@lists.xen.org
Cc: "Wei Liu" <wei.liu2@citrix.com>,
"Ian Jackson" <ian.jackson@eu.citrix.com>,
"Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>
Subject: [PATCH v3] libxl: trigger attach events for devices attached before xl devd startup
Date: Sat, 16 Jul 2016 01:47:56 +0200 [thread overview]
Message-ID: <1468626476-3072-1-git-send-email-marmarek@invisiblethingslab.com> (raw)
In-Reply-To: <20160714093617.GO31770@citrix.com>
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(+)
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:
--
2.5.5
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next prev parent reply other threads:[~2016-07-15 23:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-10 17:35 [PATCH] libxl: trigger attach events for devices attached before xl devd startup Marek Marczykowski-Górecki
2016-07-11 8:31 ` Roger Pau Monné
2016-07-11 8:56 ` Marek Marczykowski-Górecki
2016-07-11 9:43 ` Roger Pau Monné
2016-07-11 9:49 ` Marek Marczykowski-Górecki
2016-07-11 10:00 ` Roger Pau Monné
2016-07-11 10:44 ` [PATCH v2] " Marek Marczykowski-Górecki
2016-07-11 10:53 ` Roger Pau Monné
2016-07-14 9:36 ` Wei Liu
2016-07-15 23:47 ` Marek Marczykowski-Górecki [this message]
2016-07-18 15:31 ` [PATCH v3] " Wei Liu
2016-07-19 13:20 ` Wei Liu
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