diff options
| author |   Ben Gardon <bgardon@google.com> | 2021-05-18 10:34:11 -0700 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2021-06-17 13:09:26 -0400 |
| commit | b10a038e84d188e15819058b2978b2daa9853aeb (patch) | |
| tree | 6a3215a5a0ee02fcfd0e3da7fb1456d1a4756274 /Documentation/virt/kvm/locking.rst | |
| parent | KVM: mmu: Refactor memslot copy (diff) | |
| download | linux-dev-b10a038e84d188e15819058b2978b2daa9853aeb.tar.xz linux-dev-b10a038e84d188e15819058b2978b2daa9853aeb.zip | |
KVM: mmu: Add slots_arch_lock for memslot arch fields
Add a new lock to protect the arch-specific fields of memslots if they
need to be modified in a kvm->srcu read critical section. A future
commit will use this lock to lazily allocate memslot rmaps for x86.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210518173414.450044-5-bgardon@google.com>
[Add Documentation/ hunk. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt/kvm/locking.rst')
| -rw-r--r-- | Documentation/virt/kvm/locking.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst index 1fc860c007a3..35eca377543d 100644 --- a/Documentation/virt/kvm/locking.rst +++ b/Documentation/virt/kvm/locking.rst @@ -16,6 +16,11 @@ The acquisition orders for mutexes are as follows: - kvm->slots_lock is taken outside kvm->irq_lock, though acquiring them together is quite rare. +- Unlike kvm->slots_lock, kvm->slots_arch_lock is released before + synchronize_srcu(&kvm->srcu). Therefore kvm->slots_arch_lock + can be taken inside a kvm->srcu read-side critical section, + while kvm->slots_lock cannot. + On x86: - vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock |