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KVM: document memory barriers for kvm->vcpus/kvm->online_vcpus 

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
hifive-unleashed-5.1
Paolo Bonzini 2015-07-29 11:32:20 +02:00
parent c847fe8895
commit dd489240a2
2 changed files with 9 additions and 0 deletions
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4
include/linux/kvm_host.h
View File

@ -427,6 +427,10 @@ struct kvm {
static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
{
/* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case
* the caller has read kvm->online_vcpus before (as is the case
* for kvm_for_each_vcpu, for example).
*/
smp_rmb();
return kvm->vcpus[i];
}

5
virt/kvm/kvm_main.c
View File

@ -2206,6 +2206,11 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
}
kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
/*
* Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus
* before kvm->online_vcpu's incremented value.
*/
smp_wmb();
atomic_inc(&kvm->online_vcpus);