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| author | Radim Krčmář <rkrcmar@redhat.com> | 2016-03-02 22:56:53 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-03-04 09:30:29 +0100 |
| commit | 107d44a2c5bf08f221cb406b776310f12084e4de (patch) | |
| tree | f220aeb1cf3b69a1964594867532c3dfbdd5c625 /Documentation/virtual | |
| parent | KVM: i8254: turn kvm_kpit_state.reinject into atomic_t (diff) | |
| download | linux-107d44a2c5bf08f221cb406b776310f12084e4de.tar.xz linux-107d44a2c5bf08f221cb406b776310f12084e4de.zip | |
KVM: document KVM_REINJECT_CONTROL ioctl
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 24 |
1 files changed, 24 insertions, 0 deletions
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 ------------------------ |