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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2011-02-09 15:11:28 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2011-03-17 13:08:31 -0300 |
| commit | 38a778aa1899b9c6cf3e300a02782c9b78c547ab (patch) | |
| tree | 7a5714abdf9f5b8496a9dbe80e2c3b69cd6c2399 /Documentation/kvm | |
| parent | 1260edbe7de85ccc58f60040f46034831069bfa2 (diff) | |
| download | linux-38a778aa1899b9c6cf3e300a02782c9b78c547ab.tar.gz linux-38a778aa1899b9c6cf3e300a02782c9b78c547ab.tar.xz | |
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>
Diffstat (limited to 'Documentation/kvm')
| -rw-r--r-- | Documentation/kvm/locking.txt | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/kvm/locking.txt b/Documentation/kvm/locking.txt new file mode 100644 index 000000000000..3b4cd3bf5631 --- /dev/null +++ b/Documentation/kvm/locking.txt @@ -0,0 +1,25 @@ +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. |