The recursive zapping that was reintroduced by reverting "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()" can be expensive. Allow zap_gfn_range to recurse down to the PDPTE level, so that periodic yielding is possible with a finer granularity. Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/mmu/tdp_mmu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 87d8910c9ac2..53689603078a 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -926,8 +926,10 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, /* * No need to try to step down in the iterator when zapping all SPTEs, * zapping the top-level non-leaf SPTEs will recurse on their children. + * Do not do it above the 1GB level, to avoid making tdp_mmu_set_spte's + * recursion too expensive and allow yielding. */ - int min_level = zap_all ? root->role.level : PG_LEVEL_4K; + int min_level = zap_all ? PG_LEVEL_1G : PG_LEVEL_4K; end = min(end, tdp_mmu_max_gfn_host()); -- 2.31.1
