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-rw-r--r--Documentation/virtual/kvm/locking.txt19
1 files changed, 17 insertions, 2 deletions
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt
index 41b7ac9884b..f8869410d40 100644
--- a/Documentation/virtual/kvm/locking.txt
+++ b/Documentation/virtual/kvm/locking.txt
@@ -132,10 +132,14 @@ See the comments in spte_has_volatile_bits() and mmu_spte_update().
------------
Name: kvm_lock
-Type: raw_spinlock
+Type: spinlock_t
Arch: any
Protects: - vm_list
- - hardware virtualization enable/disable
+
+Name: kvm_count_lock
+Type: raw_spinlock_t
+Arch: any
+Protects: - hardware virtualization enable/disable
Comment: 'raw' because hardware enabling/disabling must be atomic /wrt
migration.
@@ -151,3 +155,14 @@ Type: spinlock_t
Arch: any
Protects: -shadow page/shadow tlb entry
Comment: it is a spinlock since it is used in mmu notifier.
+
+Name: kvm->srcu
+Type: srcu lock
+Arch: any
+Protects: - kvm->memslots
+ - kvm->buses
+Comment: The srcu read lock must be held while accessing memslots (e.g.
+ when using gfn_to_* functions) and while accessing in-kernel
+ MMIO/PIO address->device structure mapping (kvm->buses).
+ The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu
+ if it is needed by multiple functions.