Description of problem: I found out that we have code to support "xm debug-keys hhh" (same as ^A^A^A-hhh-^A^A^A) in the hypervisor, but not in the userspace because the patch was added in 3.1 time. This can be quite useful when working on machines without a serial console (for example to print VMCBs/VMCSs, to hard reboot the machine, to dump physical CPU stacks). Additional info: This is implemented by c/s 14309.
Verified with xen-3.0.3-135.el5. The userspace support for sending debug keys works now after the fix. example: # xm debug-keys h # xm dmesg ... (XEN) 'h' pressed -> showing installed handlers (XEN) key '%' (ascii '25') => Trap to xendbg (XEN) key 'C' (ascii '43') => trigger a crashdump (XEN) key 'H' (ascii '48') => dump heap info (XEN) key 'N' (ascii '4e') => NMI statistics (XEN) key 'R' (ascii '52') => reboot machine (XEN) key 'a' (ascii '61') => dump timer queues (XEN) key 'd' (ascii '64') => dump registers (XEN) key 'h' (ascii '68') => show this message (XEN) key 'i' (ascii '69') => dump interrupt bindings (XEN) key 'm' (ascii '6d') => memory info (XEN) key 'n' (ascii '6e') => trigger an NMI (XEN) key 'q' (ascii '71') => dump domain (and guest debug) info (XEN) key 'r' (ascii '72') => dump run queues (XEN) key 't' (ascii '74') => display multi-cpu clock info (XEN) key 'u' (ascii '75') => dump numa info (XEN) key 'v' (ascii '76') => dump Intel's VMCS (XEN) key 'z' (ascii '7a') => print ioapic info # xm debug-keys m # xm dmesg ... (XEN) Physical memory information: (XEN) Xen heap: 13956kB free (XEN) heap[08]: 968kB free (XEN) heap[09]: 2048kB free (XEN) heap[10]: 4096kB free (XEN) heap[11]: 8192kB free (XEN) heap[12]: 16384kB free (XEN) heap[13]: 32768kB free (XEN) heap[14]: 65536kB free (XEN) heap[15]: 131072kB free (XEN) heap[16]: 63544kB free (XEN) heap[17]: 2948kB free (XEN) heap[19]: 2020kB free (XEN) DMA heap: 329576kB free (XEN) heap[21]: 63508kB free (XEN) Dom heap: 63508kB free
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2012-0160.html