[PATCH 34/60] kvm: Keep track of plane VCPUs in struct kvm_vcpu_common

["Jörg Rödel" <joro@8bytes.org>]

From: Joerg Roedel <joerg.roedel@amd.com>

Introduce an array which keeps track of per-plane VCPU instances for a
single VCPU index. This is a short-cut to not always tranverse the
xarrays on plane switches.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 include/linux/kvm_host.h | 6 ++++++
 virt/kvm/kvm_main.c      | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b8c3f8f11cb4..5c3f9dfa15ea 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -335,6 +335,8 @@ struct kvm_vcpu_common {
 	/* Currently active VCPU */
 	struct kvm_vcpu *current_vcpu;
 
+	struct kvm_vcpu *vcpus[KVM_MAX_PLANES];
+
 	/* Locks */
 	int ____srcu_idx; /* Don't use this directly.  You've been warned. */
 #ifdef CONFIG_PROVE_RCU
@@ -382,6 +384,10 @@ struct kvm_vcpu_common {
 	struct kvm_vcpu_arch_common arch;
 };
 
+#define vcpu_for_each_plane(common, i, v)			\
+	for ((i) = 0; (i) < KVM_MAX_PLANES; ++(i))		\
+		if (((v) = common->vcpus[(i)]) != NULL)
+
 struct kvm_vcpu {
 	struct kvm *kvm;
 	struct kvm_plane *plane;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8839f91fd15e..9d30fd85ce5f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -524,6 +524,8 @@ static int kvm_vcpu_init_common(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned
 
 static void kvm_vcpu_finish_common(struct kvm_vcpu *vcpu)
 {
+	WARN_ON(vcpu->common->vcpus[vcpu->plane_level] != NULL);
+	vcpu->common->vcpus[vcpu->plane_level] = vcpu;
 	smp_wmb();
 	if (vcpu->plane_level == 0) {
 		/*
@@ -555,6 +557,7 @@ static void kvm_vcpu_common_destroy(struct kvm_vcpu *vcpu)
 
 	vcpu->common = NULL;
 	vcpu->run = NULL;
+	common->vcpus[vcpu->plane_level] = NULL;
 
 	if (vcpu->plane_level != 0)
 	       return;
-- 
2.53.0