KVM: x86: Allocate vcpu struct in common x86 code

Move allocation of VMX and SVM vcpus to common x86.  Although the struct
being allocated is technically a VMX/SVM struct, it can be interpreted
directly as a 'struct kvm_vcpu' because of the pre-existing requirement
that 'struct kvm_vcpu' be located at offset zero of the arch/vendor vcpu
struct.

Remove the message from the build-time assertions regarding placement of
the struct, as compatibility with the arch usercopy region is no longer
the sole dependent on 'struct kvm_vcpu' being at offset zero.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a3eeeb5f303e..cfcefdbe2784 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9172,26 +9172,34 @@ static void fx_init(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 {
-	void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask;
-
 	kvmclock_reset(vcpu);
 
 	kvm_x86_ops->vcpu_free(vcpu);
-	free_cpumask_var(wbinvd_dirty_mask);
+
+	free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
+	kmem_cache_free(kvm_vcpu_cache, vcpu);
 }
 
 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
 						unsigned int id)
 {
 	struct kvm_vcpu *vcpu;
+	int r;
 
 	if (kvm_check_tsc_unstable() && atomic_read(&kvm->online_vcpus) != 0)
 		printk_once(KERN_WARNING
 		"kvm: SMP vm created on host with unstable TSC; "
 		"guest TSC will not be reliable\n");
 
-	vcpu = kvm_x86_ops->vcpu_create(kvm, id);
+	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT);
+	if (!vcpu)
+		return ERR_PTR(-ENOMEM);
 
+	r = kvm_x86_ops->vcpu_create(kvm, vcpu, id);
+	if (r) {
+		kmem_cache_free(kvm_vcpu_cache, vcpu);
+		return ERR_PTR(r);
+	}
 	return vcpu;
 }