On Fri, May 26, 2023, Yu Zhao wrote:
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index 08340219c35a..6875a819e007 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -1232,6 +1232,40 @@ bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct
On 5/27/23 01:44, Yu Zhao wrote:
+#define kvm_arch_has_test_clear_young kvm_arch_has_test_clear_young
+static inline bool kvm_arch_has_test_clear_young(void)
+{
+ return IS_ENABLED(CONFIG_X86_64) &&
+ (!IS_REACHABLE(CONFIG_KVM) || (tdp_mmu_enabled &&
shadow_accessed_mask));
Implement kvm_arch_test_clear_young() to support the fast path in
mmu_notifier_ops->test_clear_young().
It focuses on a simple case, i.e., TDP MMU sets the accessed bit in
KVM PTEs and VMs are not nested, where it can rely on RCU and
clear_bit() to safely clear the accessed bit without taking
