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| author | Gleb Natapov <gleb@redhat.com> | 2011-05-04 16:31:04 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-05-22 08:48:09 -0400 |
| commit | 8fa2206821953a50a3a02ea33fcfb3ced2fd9997 (patch) | |
| tree | f4f773a0501f0fd8d3bfe30dd4851c9f0095911d /include/linux/kvm_host.h | |
| parent | e3aa52d665ec1a962d1cf025a2e5ee84b3b33406 (diff) | |
| download | linux-8fa2206821953a50a3a02ea33fcfb3ced2fd9997.tar.gz linux-8fa2206821953a50a3a02ea33fcfb3ced2fd9997.tar.bz2 linux-8fa2206821953a50a3a02ea33fcfb3ced2fd9997.zip | |
KVM: make guest mode entry to be rcu quiescent state
KVM does not hold any references to rcu protected data when it switches
CPU into a guest mode. In fact switching to a guest mode is very similar
to exiting to userspase from rcu point of view. In addition CPU may stay
in a guest mode for quite a long time (up to one time slice). Lets treat
guest mode as quiescent state, just like we do with user-mode execution.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'include/linux/kvm_host.h')
| -rw-r--r-- | include/linux/kvm_host.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 0bc3d372e3cb..b9c3299c6a55 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -591,8 +591,17 @@ static inline int kvm_deassign_device(struct kvm *kvm, static inline void kvm_guest_enter(void) { + BUG_ON(preemptible()); account_system_vtime(current); current->flags |= PF_VCPU; + /* KVM does not hold any references to rcu protected data when it + * switches CPU into a guest mode. In fact switching to a guest mode + * is very similar to exiting to userspase from rcu point of view. In + * addition CPU may stay in a guest mode for quite a long time (up to + * one time slice). Lets treat guest mode as quiescent state, just like + * we do with user-mode execution. + */ + rcu_virt_note_context_switch(smp_processor_id()); } static inline void kvm_guest_exit(void) |