KVM: Expose a version 2 architectural PMU to a guests

Use perf_events to emulate an architectural PMU, version 2.

Based on PMU version 1 emulation by Avi Kivity.

[avi: adjust for cpuid.c]
[jan: fix anonymous field initialization for older gcc]

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index ca4d49e..1a7fe86 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -35,6 +35,7 @@
 	select KVM_MMIO
 	select TASKSTATS
 	select TASK_DELAY_ACCT
+	select PERF_EVENTS
 	---help---
 	  Support hosting fully virtualized guest machines using hardware
 	  virtualization extensions.  You will need a fairly recent