On Thu, 20 Sep 2012 21:53:33 +0900, Min-gyu Kim [off-list ref]
wrote:

quoted

-----Original Message-----
From: kvm-owner at vger.kernel.org [mailto:kvm-owner at vger.kernel.org] On
Behalf Of Christoffer Dall
Sent: Sunday, September 16, 2012 12:37 AM
To: kvm at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
kvmarm at lists.cs.columbia.edu
Subject: [PATCH 01/10] ARM: KVM: Keep track of currently running vcpus

From: Marc Zyngier <redacted>

When an interrupt occurs for the guest, it is sometimes necessary to

find

quoted

out which vcpu was running at that point.

Keep track of which vcpu is being tun in kvm_arch_vcpu_ioctl_run(), and
allow the data to be retrived using either:
- kvm_arm_get_running_vcpu(): returns the vcpu running at this point
  on the current CPU. Can only be used in a non-preemptable context.

What's the purpose of kvm_arm_get_running_vcpu?
It seems to be enough to pass vcpu struct through function argument, 
and there is no caller by now.

This is also designed to be used in an interrupt handler, and is used by
the (currently out of tree) perf code:
https://lists.cs.columbia.edu/pipermail/kvmarm/2012-September/003192.html

Basically, you need this infrastructure when handling interrupts.

        M.
-- 
Fast, cheap, reliable. Pick two.