From: David Matlack Date: Mon, 16 Oct 2023 22:12:28 +0000 (-0700) Subject: KVM: x86/mmu: Stop kicking vCPUs to sync the dirty log when PML is disabled X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3d30bfcbdc268b41a7d9253a9cb3082281223b19;p=linux.git KVM: x86/mmu: Stop kicking vCPUs to sync the dirty log when PML is disabled Stop kicking vCPUs in kvm_arch_sync_dirty_log() when PML is disabled. Kicking vCPUs when PML is disabled serves no purpose and could negatively impact guest performance. This restores KVM's behavior to prior to 5.12 commit a018eba53870 ("KVM: x86: Move MMU's PML logic to common code"), which replaced a static_call_cond(kvm_x86_flush_log_dirty) with unconditional calls to kvm_vcpu_kick(). Fixes: a018eba53870 ("KVM: x86: Move MMU's PML logic to common code") Signed-off-by: David Matlack Link: https://lore.kernel.org/r/20231016221228.1348318-1-dmatlack@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 94ccad95f7e07..051ca1978442e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6355,6 +6355,9 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) struct kvm_vcpu *vcpu; unsigned long i; + if (!kvm_x86_ops.cpu_dirty_log_size) + return; + kvm_for_each_vcpu(i, vcpu, kvm) kvm_vcpu_kick(vcpu); }