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authorJan Kiszka <jan.kiszka@siemens.com>2011-02-09 15:11:28 +0100
committerMarcelo Tosatti <mtosatti@redhat.com>2011-03-17 13:08:31 -0300
commit38a778aa1899b9c6cf3e300a02782c9b78c547ab (patch)
tree7a5714abdf9f5b8496a9dbe80e2c3b69cd6c2399
parent1260edbe7de85ccc58f60040f46034831069bfa2 (diff)
KVM: Start lock documentation
The goal of this document shall be - overview of all locks used in KVM core - provide details on the scope of each lock - explain the lock type, specifically of a raw spin locks - provide a lock ordering guide Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--Documentation/kvm/locking.txt25
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+KVM Lock Overview
+=================
+
+1. Acquisition Orders
+---------------------
+
+(to be written)
+
+2. Reference
+------------
+
+Name: kvm_lock
+Type: raw_spinlock
+Arch: any
+Protects: - vm_list
+ - hardware virtualization enable/disable
+Comment: 'raw' because hardware enabling/disabling must be atomic /wrt
+ migration.
+
+Name: kvm_arch::tsc_write_lock
+Type: raw_spinlock
+Arch: x86
+Protects: - kvm_arch::{last_tsc_write,last_tsc_nsec,last_tsc_offset}
+ - tsc offset in vmcb
+Comment: 'raw' because updating the tsc offsets must not be preempted.