From 107d44a2c5bf08f221cb406b776310f12084e4de Mon Sep 17 00:00:00 2001 From: =?utf8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Date: Wed, 2 Mar 2016 22:56:53 +0100 Subject: [PATCH] KVM: document KVM_REINJECT_CONTROL ioctl MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Radim Krčmář Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/api.txt | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 110484915aa0..335fe889efd9 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3092,6 +3092,30 @@ of IOMMU pages. The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. +4.98 KVM_REINJECT_CONTROL + +Capability: KVM_CAP_REINJECT_CONTROL +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_reinject_control (in) +Returns: 0 on success, + -EFAULT if struct kvm_reinject_control cannot be read, + -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. + +i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, +where KVM queues elapsed i8254 ticks and monitors completion of interrupt from +vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its +interrupt whenever there isn't a pending interrupt from i8254. +!reinject mode injects an interrupt as soon as a tick arrives. + +struct kvm_reinject_control { + __u8 pit_reinject; + __u8 reserved[31]; +}; + +pit_reinject = 0 (!reinject mode) is recommended, unless running an old +operating system that uses the PIT for timing (e.g. Linux 2.4.x). + 5. The kvm_run structure ------------------------ -- 2.20.1