[PATCH 12/16] KVM-HV: KVM Steal time implementation

[Glauber Costa <glommer@redhat.com>]

To implement steal time, we need the hypervisor to pass the guest information
about how much time was spent running other processes outside the VM.
This is per-vcpu, and using the kvmclock structure for that is an abuse
we decided not to make.

This patch contains the hypervisor part for it. I am keeping it separate from
the headers to facilitate backports to people who wants to backport the kernel
part but not the hypervisor, or the other way around.

Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Rik van Riel <riel@redhat.com>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Avi Kivity <avi@redhat.com>
---
 arch/x86/kvm/x86.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 81b2f34..f129ea1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1564,6 +1564,11 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 			goto rma_out;
 		}
 
+		if (area_desc.type == KVM_AREA_STEAL_TIME) {
+			vcpu->arch.stime = area_desc.base;
+			goto rma_out;
+		}
+
 		if (vcpu->kvm->register_mem_area_uspace) {
 			vcpu->run->exit_reason = KVM_EXIT_X86_MSR_OP;
 			vcpu->run->msr.msr_data = data;
-- 
1.7.2.3