Messages in this thread | | | From | Olaf Hering <> | Subject | [PATCH 0/3] [v5] kexec and kdump for Xen PVonHVM guests | Date | Tue, 16 Aug 2011 15:16:50 +0200 |
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The following series implements kexec and kdump in a Xen PVonHVM guest.
It is available via git:
git://github.com/olafhering/linux.git xen-kexec-3.0
changes since v4: - drop patch which uses XS_INTRODUCE, a different way to reset watches has to be found - find_virq(): use NR_EVENT_CHANNELS instead of private MAX_EVTCHNS - reconnect devices: add timeout when waiting for backend state change extent printk message to include backend string add comment to fall-through case in xenbus_reset_frontend - new patch which prevents crash in xenwatch_thread() during repeated kexec boots
The kexec or kdump kernel has to take care of already allocated virqs, PV devices in Closed or Connected state, and of registered watches in the old kernel. With the three patches these conditions are checked during boot of the new kernel rather than in the reboot/crash path.
A fixed kexec-tools-2.0.2 package is required: http://lists.infradead.org/pipermail/kexec/2011-May/005026.html http://lists.infradead.org/pipermail/kexec/2011-August/005339.html
Another fix is for xenstored, it has to accept the XS_RESET_WATCHES from a guest. Since the exact interface to xenstored is not yet final, the patch to deal with the reset was removed from this series. http://lists.xensource.com/archives/html/xen-devel/2011-08/msg00529.html http://lists.xensource.com/archives/html/xen-devel/2011-08/msg00533.html
One open issue is the balloon driver. It removes pages from the guest and gives them back to the hypervisor. The kexec kernel is not aware of the fact that some pages are unavailable, and hangs or crashes. The workaround for the time being is:
if test -f /sys/devices/system/xen_memory/xen_memory0/target -a \ -f /sys/devices/system/xen_memory/xen_memory0/target_kb then cat /sys/devices/system/xen_memory/xen_memory0/target > \ /sys/devices/system/xen_memory/xen_memory0/target_kb fi kexec -e
This balloon issue has to be resolved with another series of changes.
Olaf
Olaf Hering (3): xen/pv-on-hvm kexec: prevent crash in xenwatch_thread() when stale watch events arrive xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports xen/pv-on-hvm kexec+kdump: reset PV devices in kexec or crash kernel
drivers/xen/events.c | 37 +++++++- drivers/xen/xenbus/xenbus_comms.c | 4 +- drivers/xen/xenbus/xenbus_probe_frontend.c | 121 ++++++++++++++++++++++++++++ drivers/xen/xenbus/xenbus_xs.c | 2 +- 4 files changed, 157 insertions(+), 7 deletions(-)
-- 1.7.3.4
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