From: Dmytro Maluka Date: Fri, 26 Sep 2025 13:51:39 +0000 (+0200) Subject: KVM: x86/mmu: Skip MMIO SPTE invalidation if enable_mmio_caching=0 X-Git-Tag: v6.19-rc1~103^2~7^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b850841a53c56665c1f623edd429b3fc1578e9a4;p=thirdparty%2Flinux.git KVM: x86/mmu: Skip MMIO SPTE invalidation if enable_mmio_caching=0 If MMIO caching is disabled, there are no MMIO SPTEs to invalidate, so the costly zapping of all pages is unnecessary even in the unlikely case when the MMIO generation number has wrapped. Signed-off-by: Dmytro Maluka Link: https://lore.kernel.org/r/20250926135139.1597781-1-dmaluka@chromium.org Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 667d66cf76d5e..18d69d48bc55a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -7364,6 +7364,9 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) { WARN_ON_ONCE(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); + if (!enable_mmio_caching) + return; + gen &= MMIO_SPTE_GEN_MASK; /*