[PATCH RFC v3 3/9] KVM: remember position in kvm->vcpus array

From: Radim KrÄmÃÅ
Date: Mon Aug 21 2017 - 16:40:24 EST


Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
---
include/linux/kvm_host.h | 11 +++--------
virt/kvm/kvm_main.c | 5 ++++-
2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6882538eda32..a8ff956616d2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -220,7 +220,8 @@ struct kvm_vcpu {
struct preempt_notifier preempt_notifier;
#endif
int cpu;
- int vcpu_id;
+ int vcpu_id; /* id given by userspace at creation */
+ int vcpus_idx; /* index in kvm->vcpus array */
int srcu_idx;
int mode;
unsigned long requests;
@@ -516,13 +517,7 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)

static inline int kvm_vcpu_get_idx(struct kvm_vcpu *vcpu)
{
- struct kvm_vcpu *tmp;
- int idx;
-
- kvm_for_each_vcpu(idx, tmp, vcpu->kvm)
- if (tmp == vcpu)
- return idx;
- BUG();
+ return vcpu->vcpus_idx;
}

#define kvm_for_each_memslot(memslot, slots) \
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e17c40d986f3..caf8323f7df7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2498,7 +2498,10 @@ 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->vcpus_idx = atomic_read(&kvm->online_vcpus);
+
+ BUG_ON(kvm->vcpus[vcpu->vcpus_idx]);
+

/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
--
2.13.3