[PATCH 4/4 v2] KVM: x86: Add a new VM statistic to show number of VCPUs created in a given VM

[Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>]

'struct kvm' already has a member for counting the number of VCPUs created
for a given VM. Add this as a new VM statistic to KVM debugfs.

Signed-off-by: Krish Sadhukhan <Krish.Sadhukhan@xxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm/svm.c          | 3 +--
 arch/x86/kvm/x86.c              | 1 +
 virt/kvm/kvm_main.c             | 2 ++
 4 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a19fe2cfaa93..69ca1d6f6557 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1139,6 +1139,7 @@ struct kvm_vm_stat {
 	ulong nx_lpage_splits;
 	ulong max_mmu_page_hash_collisions;
 	ulong vcpus_ran_nested;
+	u64 created_vcpus;
 };
 
 struct kvm_vcpu_stat {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index d1871c51411f..fef0baba043b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3875,8 +3875,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 
 		/* Track VMRUNs that have made past consistency checking */
 		if (svm->nested.nested_run_pending &&
-		    svm->vmcb->control.exit_code != SVM_EXIT_ERR &&
-		    svm->vmcb->control.exit_code != SVM_EXIT_NPF) {
+		    svm->vmcb->control.exit_code != SVM_EXIT_ERR) {
 			if (!vcpu->stat.nested_runs)
 				++vcpu->kvm->stat.vcpus_ran_nested;
                         ++vcpu->stat.nested_runs;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cbca3609a152..a9d27ce4cc93 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -258,6 +258,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VM_STAT("nx_largepages_splitted", nx_lpage_splits, .mode = 0444),
 	VM_STAT("max_mmu_page_hash_collisions", max_mmu_page_hash_collisions),
 	VM_STAT("vcpus_ran_nested", vcpus_ran_nested),
+	VM_STAT("created_vcpus", created_vcpus),
 	{ NULL }
 };
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6b4feb92dc79..ac8f02d8a051 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3318,6 +3318,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 	}
 
 	kvm->created_vcpus++;
+	kvm->stat.created_vcpus++;
 	mutex_unlock(&kvm->lock);
 
 	r = kvm_arch_vcpu_precreate(kvm, id);
@@ -3394,6 +3395,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 vcpu_decrement:
 	mutex_lock(&kvm->lock);
 	kvm->created_vcpus--;
+	kvm->stat.created_vcpus--;
 	mutex_unlock(&kvm->lock);
 	return r;
 }
-- 
2.27.0