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| author | Radim Krčmář <rkrcmar@redhat.com> | 2019-11-07 07:53:42 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-26 13:39:46 +0200 |
| commit | 41d2efaed5bdabe675857e6ecaa324b5504fc268 (patch) | |
| tree | 61d3e2b9bab19d067907bc7d6588ce5b1db3571a /virt | |
| parent | ddf58efd05b5d16d86ea4638675e8bd397320930 (diff) | |
| download | linux-stable-41d2efaed5bdabe675857e6ecaa324b5504fc268.tar.gz linux-stable-41d2efaed5bdabe675857e6ecaa324b5504fc268.tar.bz2 linux-stable-41d2efaed5bdabe675857e6ecaa324b5504fc268.zip | |
KVM: remember position in kvm->vcpus array
commit 8750e72a79dda2f665ce17b62049f4d62130d991 upstream.
Fetching an index for any vcpu in kvm->vcpus array by traversing
the entire array everytime is costly.
This patch remembers the position of each vcpu in kvm->vcpus array
by storing it in vcpus_idx under kvm_vcpu structure.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[borntraeger@de.ibm.com]: backport to 4.19 (also fits for 5.4)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a3d82113ae1c..86ef740763b5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2751,7 +2751,8 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) goto unlock_vcpu_destroy; } - BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]); + vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus); + BUG_ON(kvm->vcpus[vcpu->vcpu_idx]); /* Now it's all set up, let userspace reach it */ kvm_get_kvm(kvm); @@ -2761,7 +2762,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) goto unlock_vcpu_destroy; } - kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu; + kvm->vcpus[vcpu->vcpu_idx] = vcpu; /* * Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus |