Merge remote-tracking branch 'y2038/y2038'

[karo-tx-linux.git] / Documentation / virtual / kvm / locking.txt

diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt
index d68af4dc300630b888d0d68f0227597d8bebb37d..19f94a6b9bb0df62d804eadd6eabb40132b996d2 100644 (file)
--- a/Documentation/virtual/kvm/locking.txt
+++ b/Documentation/virtual/kvm/locking.txt
@@ -166,3 +166,15 @@ Comment:   The srcu read lock must be held while accessing memslots (e.g.
                MMIO/PIO address->device structure mapping (kvm->buses).
                The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu
                if it is needed by multiple functions.
+
+Name:          blocked_vcpu_on_cpu_lock
+Type:          spinlock_t
+Arch:          x86
+Protects:      blocked_vcpu_on_cpu
+Comment:       This is a per-CPU lock and it is used for VT-d posted-interrupts.
+               When VT-d posted-interrupts is supported and the VM has assigned
+               devices, we put the blocked vCPU on the list blocked_vcpu_on_cpu
+               protected by blocked_vcpu_on_cpu_lock, when VT-d hardware issues
+               wakeup notification event since external interrupts from the
+               assigned devices happens, we will find the vCPU on the list to
+               wakeup.