[PATCH v6 17/29] KVM: x86: Don't call kvm_mmu_change_mmu_pages() if the count hasn't changed

["Maciej S. Szmigiero" <mail@xxxxxxxxxxxxxxxxxxxxx>]

From: "Maciej S. Szmigiero" <maciej.szmigiero@xxxxxxxxxx>

There is no point in calling kvm_mmu_change_mmu_pages() for memslot
operations that don't change the total page count, so do it just for
KVM_MR_CREATE and KVM_MR_DELETE.

Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/x86/kvm/x86.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f25d224d21d9..13048683db60 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11832,7 +11832,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 				const struct kvm_memory_slot *new,
 				enum kvm_mr_change change)
 {
-	if (!kvm->arch.n_requested_mmu_pages)
+	if (!kvm->arch.n_requested_mmu_pages &&
+	    (change == KVM_MR_CREATE || change == KVM_MR_DELETE))
 		kvm_mmu_change_mmu_pages(kvm,
 				kvm_mmu_calculate_default_mmu_pages(kvm));