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| author | Rik van Riel <riel@redhat.com> | 2011-02-01 09:52:41 -0500 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2011-03-17 13:08:29 -0300 |
| commit | 34bb10b79de7df118de832f6832efb630e646577 (patch) | |
| tree | 2284a88be869a13a55b0435eafa572cde9ae53aa | |
| parent | 77c100c83e84316ced2507c5799f79c2c80bc6b9 (diff) | |
| download | linux-34bb10b79de7df118de832f6832efb630e646577.tar.bz2 | |
KVM: keep track of which task is running a KVM vcpu
Keep track of which task is running a KVM vcpu. This helps us
figure out later what task to wake up if we want to boost a
vcpu that got preempted.
Unfortunately there are no guarantees that the same task
always keeps the same vcpu, so we can only track the task
across a single "run" of the vcpu.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | include/linux/kvm_host.h | 1 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 10 |
2 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c8dee22b1945..4721b11b922a 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -122,6 +122,7 @@ struct kvm_vcpu { int fpu_active; int guest_fpu_loaded, guest_xcr0_loaded; wait_queue_head_t wq; + struct pid *pid; int sigset_active; sigset_t sigset; struct kvm_vcpu_stat stat; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 002fe0b12c9f..bc8bfd15ab71 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -137,6 +137,14 @@ void vcpu_load(struct kvm_vcpu *vcpu) int cpu; mutex_lock(&vcpu->mutex); + if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) { + /* The thread running this VCPU changed. */ + struct pid *oldpid = vcpu->pid; + struct pid *newpid = get_task_pid(current, PIDTYPE_PID); + rcu_assign_pointer(vcpu->pid, newpid); + synchronize_rcu(); + put_pid(oldpid); + } cpu = get_cpu(); preempt_notifier_register(&vcpu->preempt_notifier); kvm_arch_vcpu_load(vcpu, cpu); @@ -212,6 +220,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) vcpu->cpu = -1; vcpu->kvm = kvm; vcpu->vcpu_id = id; + vcpu->pid = NULL; init_waitqueue_head(&vcpu->wq); kvm_async_pf_vcpu_init(vcpu); @@ -236,6 +245,7 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_init); void kvm_vcpu_uninit(struct kvm_vcpu *vcpu) { + put_pid(vcpu->pid); kvm_arch_vcpu_uninit(vcpu); free_page((unsigned long)vcpu->run); } |