similar to: watches not working from domU userspace

hi, I am trying to add xenbus watch support to mini-os, but am getting into a endless loop of watches firing over and over. Below is an excerpt from the xenstore tracefile: IN 0x805acc8 20070103 19:32:18 WATCH (/local/domain/0/backend/vif/26/0/state 00043818 ) CREATE watch 0x805a8b8 OUT 0x805acc8 20070103 19:32:18 WATCH (OK ) OUT 0x805acc8 20070103 19:32:18 WATCH_EVENT

Hello, This patch allows userspace tools on a domU to setup a watch on the xenstore. It does this by intercepting XS_WATCH requests written to /proc/xen/xenbus and then re-submitting the request to the in-kernel xenstore interface, in linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_xs.c. When a callback occurs, an in-kernel function is invoked, which then reconstructs a response in the format

Hi, Anybody (Christian?) could please tell me if we can get the support for registering watch with /proc/xen/xenbus? (..OK, I know that we will change it this /proc stuff to a device soon) So far we can only do read/write/rm. I really miss the xen watch feature. Many thanks, Hieu _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com

As any other daemon, I''d assume it should be possible to restart xenstored (i.e. if it crashed or if, during development, a fix was made to it that needs to be tested). However, as I learned after over a day of digging, things don''t work anymore after doing so: Since the watches are transient, they''re lost with the daemon going away. Right now I specifically need this in

Add xs_reset_watches function to shutdown watches from old kernel after kexec boot. The old kernel does not unregister all watches in the shutdown path. They are still active, the double registration can not be detected by the new kernel. When the watches fire, unexpected events will arrive and the xenwatch thread will crash (jumps to NULL). An orderly reboot of a hvm guest will destroy the

The following series improves kexec in a Xen PVonHVM guest. It is available via git: git://github.com/olafhering/linux.git xen-kexec-XS_RESET_WATCHES-3.0 A new xenstored command XS_RESET_WATCHES has been added in xen-unstable.hg changeset 23839:42a45baf037d. The command removes all watches and transactions for the guest. The following patches make use of the new command to wipe all existing

Currently PVHVM Linux guests after ddacf5ef684a "xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel" hang when run against oxenstored because it does not handle the unknown XS_RESET_WATCHES operation and does not reply. The symptom of this issue is a hang during boot at this point: cpu 1 spinlock event irq 70 CPU 1 irqstacks, hard=dec94000

I''m running Xen3 7775 with udev 073 (which was a PITA to get working, as the initrd I''ve been running for quite some time uses an older one -- but that''s an entirely different story). My dom0 is Gentoo-based. When I try to start a DomU, it times out waiting for hotplug-based notification, as per the following: DEBUG (DevController:69) Waiting for devices vif. DEBUG

I''m running Xen3 7775 with udev 073 (which was a PITA to get working, as the initrd I''ve been running for quite some time uses an older one -- but that''s an entirely different story). My dom0 is Gentoo-based. When I try to start a DomU, it times out waiting for hotplug-based notification, as per the following: DEBUG (DevController:69) Waiting for devices vif. DEBUG

I''m looking at building a xenstore-based watchdog, as described at http://lists.xensource.com/archives/html/xen-users/2005-07/msg00597.html However, being somewhat new to xenstore, I''d appreciate some pointers. - What portions of the xenstore namespace should I use? I''m looking for at least two settings writable by the DomUs: A flag to enable/disable the watchdog

I noticed that the changesets around 7378:bd3268de4145 introduced the xen_domain_handle_t param to xc_create_domain(), the struct domain, etc. and call it a "tool UUID". Can someone explain how this is envisioned being used (xend sets it to some magic values but I don''t see it get used anywhere)? Joe _______________________________________________ Xen-devel mailing list

Hi, I am writing a small application to watch for xenstore events. I want to know when a specific domain shutdown or reboot. It is best to watch it via xenbus interface, but how? Is there any event or node can give me such an event? If not, I must periodically scan the domains (using libxc interface) to detect if a domain dies, but that is not as good as xenbus approach. Many thanks. Hieu

Hi, for debugging purposes I would like to see the existing xenstore watches and the waiters for the watch. The problem is, we got a EEXIST from xenstored while trying to set a watch from our guest. Is there a possibility to see this on the running xenstored? Thanks. Dietmar. -- Company details: http://ts.fujitsu.com/imprint.html

XenStore puts in queued watch events via a thread and notifies the user. Sometimes xs_unwatch is called before all related message is read. The use case is non-threaded libevent, we have two event A and B: - Event A will destroy something and call xs_unwatch; - Event B is used to notify that a node has changed in XenStore. As the event is called one by one, event A can be handled before

# HG changeset patch # User Ian Campbell <ian.campbell@citrix.com> # Date 1322568055 0 # Node ID 6da8c30fb198adc15136a867a8303b7de3804bcf # Parent fa9deee858b84d4c4fbb5f9523fa5adb7aac3a35 docs: XenBus page has been transfered to new wiki Signed-off-by: Ian Campbell <Ian.Campbell@citrix.com> diff -r fa9deee858b8 -r 6da8c30fb198 docs/misc/xenstore.txt --- a/docs/misc/xenstore.txt Tue

I''ve been trying to track down just why talking to XenD is resulting in so much CPU time being comsumed by both xend & xenstored. As a test case, I''m running ''virsh dominfo demo'' which results in a single HTTP request to Xend to fetch domain info, eg ''GET /xend/domains/demo'' Run this in a tight loop & I''ll see xenstored

I accidentally realized today that any domU''s using the paravirt disk driver potentially suffer from poor performance when they get handed in a physical volume and partitioning is done inside the guest. The physical volume passed in has to be one that has the compat 512 logical sector size but hints its real sector size (eg. 4096) as physical sector size. In dom0 handling is correct and

Hi, George sent a patch on this problem before, but it was not completed. This patch makes libxl use xenbus to communicate with xenstored if libxl cannot open a socket. There''s a place that does not close fd in the case of failure, which is also fixed in this patch. -----------------------------------------Patch------------------------------------------------------ diff -r eff592364826

I just downloaded Xen-4.1.1 from xen.org, compiled it, and installed it. I then compiled kernel 3.0.0 and added the hypervisor and dom0 kernel in a grub 2 entry. After booting, I executed "xl list," to confirm the hypervisor was running. I was greeted with this message: libxl: error: libxl.c:56:libxl_ctx_init Is xenstore daemon running? failed to stat /var/run/xenstored.pid: No such

Changes from v3: - mini-os configuration files moved into stubdom/ - mini-os extra console support now a config option - Fewer #ifdefs - grant table setup uses hypercall bounce - Xenstore stub domain syslog support re-enabled Changes from v2: - configuration support added to mini-os build system - add mini-os support for conditionally compiling frontends, xenbus -