KVM: VMX: add module parameter to avoid trapping HLT instructions (v5)

In certain use-cases, we want to allocate guests fixed time slices where idle
guest cycles leave the machine idling.  There are many approaches to achieve
this but the most direct is to simply avoid trapping the HLT instruction which
lets the guest directly execute the instruction putting the processor to sleep.

Introduce this as a module-level option for kvm-vmx.ko since if you do this
for one guest, you probably want to do it for all.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 42d959056f97..9642c2216f31 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -297,6 +297,12 @@ enum vmcs_field {
 #define GUEST_INTR_STATE_SMI            0x00000004
 #define GUEST_INTR_STATE_NMI            0x00000008
 
+/* GUEST_ACTIVITY_STATE flags */
+#define GUEST_ACTIVITY_ACTIVE           0
+#define GUEST_ACTIVITY_HLT              1
+#define GUEST_ACTIVITY_SHUTDOWN         2
+#define GUEST_ACTIVITY_WAIT_SIPI        3
+
 /*
  * Exit Qualifications for MOV for Control Register Access
  */