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authorPaolo Bonzini <pbonzini@redhat.com>2016-12-12 10:12:53 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2016-12-16 17:53:38 +0100
commit3f5ad8be3713572f3946b69eb376206153d0ea2d (patch)
tree90ca8a72bf9fd7fc79652a8c772f00ae32574606 /Documentation
parent83781d180b219bd079ae72b341ee3f21fb236e97 (diff)
downloadlinux-stericsson-3f5ad8be3713572f3946b69eb376206153d0ea2d.tar.gz
KVM: hyperv: fix locking of struct kvm_hv fields
Introduce a new mutex to avoid an AB-BA deadlock between kvm->lock and vcpu->mutex. Protect accesses in kvm_hv_setup_tsc_page too, as suggested by Roman. Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virtual/kvm/locking.txt8
1 files changed, 6 insertions, 2 deletions
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt
index e5dd9f4d6100..fd013bf4115b 100644
--- a/Documentation/virtual/kvm/locking.txt
+++ b/Documentation/virtual/kvm/locking.txt
@@ -13,8 +13,12 @@ The acquisition orders for mutexes are as follows:
- kvm->slots_lock is taken outside kvm->irq_lock, though acquiring
them together is quite rare.
-For spinlocks, kvm_lock is taken outside kvm->mmu_lock. Everything
-else is a leaf: no other lock is taken inside the critical sections.
+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
------------