xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports
xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports

During a kexec boot some virqs such as timer and debugirq were already
registered by the old kernel.  The hypervisor will return -EEXISTS from
the new EVTCHNOP_bind_virq request and the BUG in bind_virq_to_irq()
triggers.  Catch the -EEXISTS error and loop through all possible ports to find
what port belongs to the virq/cpu combo.

Signed-off-by: Olaf Hering <ded022db89399a060a39da31922f173c6556c2d9@aepfle.de>
[v2:
  - use NR_EVENT_CHANNELS instead of private MAX_EVTCHNS]
Signed-off-by: Konrad Rzeszutek Wilk <da3a51b335cef0eb0e2c329c5ef6bcd6acef687a@oracle.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas