KVM: PIT: provide an option to disable interrupt reinjection

Certain clocks (such as TSC) in older 2.6 guests overaccount for lost
ticks, causing severe time drift. Interrupt reinjection magnifies the
problem.

Provide an option to disable it.

[avi: allow room for expansion in case we want to disable reinjection
      of other timers]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index 32eb96c7ca27..54bcf2281526 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -233,4 +233,9 @@ struct kvm_guest_debug_arch {
 struct kvm_pit_state {
         struct kvm_pit_channel_state channels[3];
 };
+
+struct kvm_reinject_control {
+        __u8 pit_reinject;
+        __u8 reserved[31];
+};
 #endif /* _ASM_X86_KVM_H */