From f3b65bbaed7c43d10989380d4b95e2a3e9fe5a6b Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 5 Apr 2024 07:58:12 -0400 Subject: KVM: delete .change_pte MMU notifier callback The .change_pte() MMU notifier callback was intended as an optimization. The original point of it was that KSM could tell KVM to flip its secondary PTE to a new location without having to first zap it. At the time there was also an .invalidate_page() callback; both of them were *not* bracketed by calls to mmu_notifier_invalidate_range_{start,end}(), and .invalidate_page() also doubled as a fallback implementation of .change_pte(). Later on, however, both callbacks were changed to occur within an invalidate_range_start/end() block. In the case of .change_pte(), commit 6bdb913f0a70 ("mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end", 2012-10-09) did so to remove the fallback from .invalidate_page() to .change_pte() and allow sleepable .invalidate_page() hooks. This however made KVM's usage of the .change_pte() callback completely moot, because KVM unmaps the sPTEs during .invalidate_range_start() and therefore .change_pte() has no hope of finding a sPTE to change. Drop the generic KVM code that dispatches to kvm_set_spte_gfn(), as well as all the architecture specific implementations. Signed-off-by: Paolo Bonzini Acked-by: Anup Patel Acked-by: Michael Ellerman (powerpc) Reviewed-by: Bibo Mao Message-ID: <20240405115815.3226315-2-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini --- arch/powerpc/kvm/book3s.c | 5 ----- arch/powerpc/kvm/book3s.h | 1 - arch/powerpc/kvm/book3s_64_mmu_hv.c | 12 ------------ arch/powerpc/kvm/book3s_hv.c | 1 - arch/powerpc/kvm/book3s_pr.c | 7 ------- arch/powerpc/kvm/e500_mmu_host.c | 6 ------ 6 files changed, 32 deletions(-) (limited to 'arch/powerpc/kvm') diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 8acec144120e..0d0624088e6b 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -899,11 +899,6 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) return kvm->arch.kvm_ops->test_age_gfn(kvm, range); } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - return kvm->arch.kvm_ops->set_spte_gfn(kvm, range); -} - int kvmppc_core_init_vm(struct kvm *kvm) { diff --git a/arch/powerpc/kvm/book3s.h b/arch/powerpc/kvm/book3s.h index 58391b4b32ed..4aa2ab89afbc 100644 --- a/arch/powerpc/kvm/book3s.h +++ b/arch/powerpc/kvm/book3s.h @@ -12,7 +12,6 @@ extern void kvmppc_core_flush_memslot_hv(struct kvm *kvm, extern bool kvm_unmap_gfn_range_hv(struct kvm *kvm, struct kvm_gfn_range *range); extern bool kvm_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range); extern bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range); -extern bool kvm_set_spte_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range); extern int kvmppc_mmu_init_pr(struct kvm_vcpu *vcpu); extern void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu); diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 2b1f0cdd8c18..1b51b1c4713b 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -1010,18 +1010,6 @@ bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range) return kvm_test_age_rmapp(kvm, range->slot, range->start); } -bool kvm_set_spte_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range) -{ - WARN_ON(range->start + 1 != range->end); - - if (kvm_is_radix(kvm)) - kvm_unmap_radix(kvm, range->slot, range->start); - else - kvm_unmap_rmapp(kvm, range->slot, range->start); - - return false; -} - static int vcpus_running(struct kvm *kvm) { return atomic_read(&kvm->arch.vcpus_running) != 0; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 8e86eb577eb8..35cb014a0c51 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -6364,7 +6364,6 @@ static struct kvmppc_ops kvm_ops_hv = { .unmap_gfn_range = kvm_unmap_gfn_range_hv, .age_gfn = kvm_age_gfn_hv, .test_age_gfn = kvm_test_age_gfn_hv, - .set_spte_gfn = kvm_set_spte_gfn_hv, .free_memslot = kvmppc_core_free_memslot_hv, .init_vm = kvmppc_core_init_vm_hv, .destroy_vm = kvmppc_core_destroy_vm_hv, diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 5b92619a05fd..a7d7137ea0c8 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -461,12 +461,6 @@ static bool kvm_test_age_gfn_pr(struct kvm *kvm, struct kvm_gfn_range *range) return false; } -static bool kvm_set_spte_gfn_pr(struct kvm *kvm, struct kvm_gfn_range *range) -{ - /* The page will get remapped properly on its next fault */ - return do_kvm_unmap_gfn(kvm, range); -} - /*****************************************/ static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr) @@ -2071,7 +2065,6 @@ static struct kvmppc_ops kvm_ops_pr = { .unmap_gfn_range = kvm_unmap_gfn_range_pr, .age_gfn = kvm_age_gfn_pr, .test_age_gfn = kvm_test_age_gfn_pr, - .set_spte_gfn = kvm_set_spte_gfn_pr, .free_memslot = kvmppc_core_free_memslot_pr, .init_vm = kvmppc_core_init_vm_pr, .destroy_vm = kvmppc_core_destroy_vm_pr, diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c index ccb8f16ffe41..c664fdec75b1 100644 --- a/arch/powerpc/kvm/e500_mmu_host.c +++ b/arch/powerpc/kvm/e500_mmu_host.c @@ -747,12 +747,6 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) return false; } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - /* The page will get remapped properly on its next fault */ - return kvm_e500_mmu_unmap_gfn(kvm, range); -} - /*****************************************/ int e500_mmu_host_init(struct kvmppc_vcpu_e500 *vcpu_e500) -- cgit v1.2.3