Revert "KVM: SVM: Do not throw warning when calling avic_vcpu_load on a running vcpu"

jira LE-1907
Rebuild_History Non-Buildable kernel-5.14.0-284.30.1.el9_2
commit-author Sean Christopherson <seanjc@google.com>
commit e2ed3e6

Turns out that some warnings exist for good reasons.  Restore the warning
in avic_vcpu_load() that guards against calling avic_vcpu_load() on a
running vCPU now that KVM avoids doing so when switching between x2APIC
and xAPIC.  The entire point of the WARN is to highlight that KVM should
not be reloading an AVIC.

Opportunistically convert the WARN_ON() to WARN_ON_ONCE() to avoid
spamming the kernel if it does fire.

This reverts commit c0caeee.

	Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
	Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230106011306.85230-31-seanjc@google.com>
	Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit e2ed3e6)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

Author: PlaidCat

arch/x86/kvm/svm/avic.c

@@ -1034,6 +1034,7 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 		return;
 
 	entry = READ_ONCE(*(svm->avic_physical_id_cache));
+	WARN_ON_ONCE(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK);
 
 	entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK;
 	entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK);