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Diffstat (limited to 'Documentation/virtual/kvm/locking.txt')
| -rw-r--r-- | Documentation/virtual/kvm/locking.txt | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index f2491a8c68b4..fd013bf4115b 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -4,7 +4,21 @@ KVM Lock Overview 1. Acquisition Orders --------------------- -(to be written) +The acquisition orders for mutexes are as follows: + +- kvm->lock is taken outside vcpu->mutex + +- kvm->lock is taken outside kvm->slots_lock and kvm->irq_lock + +- kvm->slots_lock is taken outside kvm->irq_lock, though acquiring + them together is quite rare. + +On x86, vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock. + +For spinlocks, kvm_lock is taken outside kvm->mmu_lock. + +Everything else is a leaf: no other lock is taken inside the critical +sections. 2: Exception ------------ |