X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=Documentation%2Fvirtual%2Fkvm%2Fhypercalls.txt;h=022198e389d7e6066b8101292199fa25bcde84e4;hb=9bc6cbebfe006bcf0f83b10221cd4b893a130d10;hp=ea113b5d87a4a8530fcc32f57a4da78c6e9e7281;hpb=64acba6a7adfe8be2e28b7e903092db685328a08;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
index ea113b5..022198e 100644
--- a/Documentation/virtual/kvm/hypercalls.txt
+++ b/Documentation/virtual/kvm/hypercalls.txt
@@ -64,3 +64,17 @@ Purpose: To enable communication between the hypervisor and guest there is a
 shared page that contains parts of supervisor visible register state.
 The guest can map this shared page to access its supervisor register through
 memory using this hypercall.
+
+5. KVM_HC_KICK_CPU
+------------------------
+Architecture: x86
+Status: active
+Purpose: Hypercall used to wakeup a vcpu from HLT state
+Usage example : A vcpu of a paravirtualized guest that is busywaiting in guest
+kernel mode for an event to occur (ex: a spinlock to become available) can
+execute HLT instruction once it has busy-waited for more than a threshold
+time-interval. Execution of HLT instruction would cause the hypervisor to put
+the vcpu to sleep until occurence of an appropriate event. Another vcpu of the
+same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall,
+specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0)
+is used in the hypercall for future use.