diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2023-11-25 03:33:59 -0500 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-12-01 07:52:08 -0800 |
| commit | 250ce1b4d21a94f910c3df5141ff6434ea92524e (patch) | |
| tree | e04b9c330262a9edbb83ce90a729ee8f200ab279 /Documentation/virt | |
| parent | 484dd27c0602e01cb49db362ad42b95e70912d43 (diff) | |
| download | linux-250ce1b4d21a94f910c3df5141ff6434ea92524e.tar.gz | |
KVM: x86/mmu: always take tdp_mmu_pages_lock
It is cheap to take tdp_mmu_pages_lock in all write-side critical sections.
We already do it all the time when zapping with read_lock(), so it is not
a problem to do it from the kvm_tdp_mmu_zap_all() path (aka
kvm_arch_flush_shadow_all(), aka VM destruction and MMU notifier release).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20231125083400.1399197-4-pbonzini@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'Documentation/virt')
| -rw-r--r-- | Documentation/virt/kvm/locking.rst | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst index 3a034db5e55f8..02880d5552d5f 100644 --- a/Documentation/virt/kvm/locking.rst +++ b/Documentation/virt/kvm/locking.rst @@ -43,10 +43,9 @@ On x86: - vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock and kvm->arch.xen.xen_lock -- kvm->arch.mmu_lock is an rwlock. kvm->arch.tdp_mmu_pages_lock and - kvm->arch.mmu_unsync_pages_lock are taken inside kvm->arch.mmu_lock, and - cannot be taken without already holding kvm->arch.mmu_lock (typically with - ``read_lock`` for the TDP MMU, thus the need for additional spinlocks). +- kvm->arch.mmu_lock is an rwlock; critical sections for + kvm->arch.tdp_mmu_pages_lock and kvm->arch.mmu_unsync_pages_lock must + also take kvm->arch.mmu_lock Everything else is a leaf: no other lock is taken inside the critical sections. |