KVM: Split vcpu creation to avoid vcpu_load() before preemption setup

Split kvm_arch_vcpu_create() into kvm_arch_vcpu_create() and
kvm_arch_vcpu_setup(), enabling preemption notification between the two.
This mean that we can now do vcpu_load() within kvm_arch_vcpu_setup().

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 7 insertions, 9 deletions

diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 6abb2ed1a908..b482b6a8a828 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -2478,13 +2478,12 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
                                                 unsigned int id)
 {
-        int r;
-        struct kvm_vcpu *vcpu = kvm_x86_ops->vcpu_create(kvm, id);
+        return kvm_x86_ops->vcpu_create(kvm, id);
+}
 
-        if (IS_ERR(vcpu)) {
-                r = -ENOMEM;
-                goto fail;
-        }
+int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+        int r;
 
         /* We do fxsave: this must be aligned. */
         BUG_ON((unsigned long)&vcpu->host_fx_image & 0xF);
@@ -2497,11 +2496,10 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
         if (r < 0)
                 goto free_vcpu;
 
-        return vcpu;
+        return 0;
 free_vcpu:
         kvm_x86_ops->vcpu_free(vcpu);
-fail:
-        return ERR_PTR(r);
+        return r;
 }
 
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)