From patchwork Fri Apr 5 11:58:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13618951 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7362E16C6BC for ; Fri, 5 Apr 2024 11:58:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318310; cv=none; b=FB8e1rOjw4FA8k4EqRDmtfVSwkd5smFh4xn7Qnj97oNOiUNJVyFL4wtDOFIDsAr97Ey1UpsWAdHlvAu18b6UBaoSZjRxMl8ctKlviCKCc9gZzBI2RqCoiALMduA5BeSXYed5v1op/besv2GhYCuaPi/1RDb2+hhlyqV1+3c1dPA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318310; c=relaxed/simple; bh=Qp0dmDa1jRvH5xbuAdztQUxb+P8roLnIe0/xOVBCeQo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZHRszDbrXRrwmnO/Umno6ciEAzXAIg80kWbkLqpE374j7Q/VaMskRUnG1talQb7MotTUUhbMf9G+af114d/HWSayXn+hD8v20XGHm0oWc8r2qjaOykp3xG4hF801jwV7inpSm4jk7VG/zJHoDeJnqXUwCl59ppDK4AyjFg0YEXo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=AZZqYpGt; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AZZqYpGt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712318305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Wytamjt4i4/TmNza1qXkp+jO67L0V+arhl6Owo1MbtM=; b=AZZqYpGthcxYy6l3ZHT1CK1JRgjtsvcttJun+ke9uHyxwnvwRE8qp5z6MRjQqrJ7tYP0vE lPZWMuiMxZlSDi1BBNfk6H8Mg1Hk21iAB2szzGs/JRKzaXCt6rk8gCz/rzio2FzoleI/Qh 2jSX2GpWsULyKztK1aghpu1h6IE9BFk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-177-BrVtY9xqPAqcqDQHveEs3w-1; Fri, 05 Apr 2024 07:58:20 -0400 X-MC-Unique: BrVtY9xqPAqcqDQHveEs3w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3BA2585A58B; Fri, 5 Apr 2024 11:58:19 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7696540C6CC1; Fri, 5 Apr 2024 11:58:18 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Thomas Bogendoerfer , Nicholas Piggin , Anup Patel , Atish Patra , Sean Christopherson , Andrew Morton , David Hildenbrand , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH 1/4] KVM: delete .change_pte MMU notifier callback Date: Fri, 5 Apr 2024 07:58:12 -0400 Message-ID: <20240405115815.3226315-2-pbonzini@redhat.com> In-Reply-To: <20240405115815.3226315-1-pbonzini@redhat.com> References: <20240405115815.3226315-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 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 Reviewed-by: Bibo Mao Acked-by: Michael Ellerman (powerpc) Acked-by: Will Deacon --- arch/arm64/kvm/mmu.c | 34 ----------------- arch/loongarch/include/asm/kvm_host.h | 1 - arch/loongarch/kvm/mmu.c | 32 ---------------- arch/mips/kvm/mmu.c | 30 --------------- arch/powerpc/include/asm/kvm_ppc.h | 1 - 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 --- arch/riscv/kvm/mmu.c | 20 ---------- arch/x86/kvm/mmu/mmu.c | 54 +-------------------------- arch/x86/kvm/mmu/spte.c | 16 -------- arch/x86/kvm/mmu/spte.h | 2 - arch/x86/kvm/mmu/tdp_mmu.c | 46 ----------------------- arch/x86/kvm/mmu/tdp_mmu.h | 1 - include/linux/kvm_host.h | 2 - include/trace/events/kvm.h | 15 -------- virt/kvm/kvm_main.c | 43 --------------------- 20 files changed, 2 insertions(+), 327 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index dc04bc767865..ff17849be9f4 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1768,40 +1768,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) return false; } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - kvm_pfn_t pfn = pte_pfn(range->arg.pte); - - if (!kvm->arch.mmu.pgt) - return false; - - WARN_ON(range->end - range->start != 1); - - /* - * If the page isn't tagged, defer to user_mem_abort() for sanitising - * the MTE tags. The S2 pte should have been unmapped by - * mmu_notifier_invalidate_range_end(). - */ - if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn))) - return false; - - /* - * We've moved a page around, probably through CoW, so let's treat - * it just like a translation fault and the map handler will clean - * the cache to the PoC. - * - * The MMU notifiers will have unmapped a huge PMD before calling - * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and - * therefore we never need to clear out a huge PMD through this - * calling path and a memcache is not required. - */ - kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT, - PAGE_SIZE, __pfn_to_phys(pfn), - KVM_PGTABLE_PROT_R, NULL, 0); - - return false; -} - bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { u64 size = (range->end - range->start) << PAGE_SHIFT; diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h index 2d62f7b0d377..69305441f40d 100644 --- a/arch/loongarch/include/asm/kvm_host.h +++ b/arch/loongarch/include/asm/kvm_host.h @@ -203,7 +203,6 @@ void kvm_flush_tlb_all(void); void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa); int kvm_handle_mm_fault(struct kvm_vcpu *vcpu, unsigned long badv, bool write); -void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte); int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end, bool blockable); int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end); int kvm_test_age_hva(struct kvm *kvm, unsigned long hva); diff --git a/arch/loongarch/kvm/mmu.c b/arch/loongarch/kvm/mmu.c index a556cff35740..98883aa23ab8 100644 --- a/arch/loongarch/kvm/mmu.c +++ b/arch/loongarch/kvm/mmu.c @@ -494,38 +494,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) range->end << PAGE_SHIFT, &ctx); } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - unsigned long prot_bits; - kvm_pte_t *ptep; - kvm_pfn_t pfn = pte_pfn(range->arg.pte); - gpa_t gpa = range->start << PAGE_SHIFT; - - ptep = kvm_populate_gpa(kvm, NULL, gpa, 0); - if (!ptep) - return false; - - /* Replacing an absent or old page doesn't need flushes */ - if (!kvm_pte_present(NULL, ptep) || !kvm_pte_young(*ptep)) { - kvm_set_pte(ptep, 0); - return false; - } - - /* Fill new pte if write protected or page migrated */ - prot_bits = _PAGE_PRESENT | __READABLE; - prot_bits |= _CACHE_MASK & pte_val(range->arg.pte); - - /* - * Set _PAGE_WRITE or _PAGE_DIRTY iff old and new pte both support - * _PAGE_WRITE for map_page_fast if next page write fault - * _PAGE_DIRTY since gpa has already recorded as dirty page - */ - prot_bits |= __WRITEABLE & *ptep & pte_val(range->arg.pte); - kvm_set_pte(ptep, kvm_pfn_pte(pfn, __pgprot(prot_bits))); - - return true; -} - bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { kvm_ptw_ctx ctx; diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c index 467ee6b95ae1..c17157e700c0 100644 --- a/arch/mips/kvm/mmu.c +++ b/arch/mips/kvm/mmu.c @@ -444,36 +444,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) return true; } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - gpa_t gpa = range->start << PAGE_SHIFT; - pte_t hva_pte = range->arg.pte; - pte_t *gpa_pte = kvm_mips_pte_for_gpa(kvm, NULL, gpa); - pte_t old_pte; - - if (!gpa_pte) - return false; - - /* Mapping may need adjusting depending on memslot flags */ - old_pte = *gpa_pte; - if (range->slot->flags & KVM_MEM_LOG_DIRTY_PAGES && !pte_dirty(old_pte)) - hva_pte = pte_mkclean(hva_pte); - else if (range->slot->flags & KVM_MEM_READONLY) - hva_pte = pte_wrprotect(hva_pte); - - set_pte(gpa_pte, hva_pte); - - /* Replacing an absent or old page doesn't need flushes */ - if (!pte_present(old_pte) || !pte_young(old_pte)) - return false; - - /* Pages swapped, aged, moved, or cleaned require flushes */ - return !pte_present(hva_pte) || - !pte_young(hva_pte) || - pte_pfn(old_pte) != pte_pfn(hva_pte) || - (pte_dirty(old_pte) && !pte_dirty(hva_pte)); -} - bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { return kvm_mips_mkold_gpa_pt(kvm, range->start, range->end); diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index 3281215097cc..ca3829d47ab7 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -287,7 +287,6 @@ struct kvmppc_ops { bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range); bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range); bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range); - bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range); void (*free_memslot)(struct kvm_memory_slot *slot); int (*init_vm)(struct kvm *kvm); void (*destroy_vm)(struct kvm *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) diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index a9e2fd7245e1..b63650f9b966 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -550,26 +550,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) return false; } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - int ret; - kvm_pfn_t pfn = pte_pfn(range->arg.pte); - - if (!kvm->arch.pgd) - return false; - - WARN_ON(range->end - range->start != 1); - - ret = gstage_map_page(kvm, NULL, range->start << PAGE_SHIFT, - __pfn_to_phys(pfn), PAGE_SIZE, true, true); - if (ret) { - kvm_debug("Failed to map G-stage page (error %d)\n", ret); - return true; - } - - return false; -} - bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { pte_t *ptep; diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 0049d49aa913..87ba2a9da196 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -432,8 +432,8 @@ static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) * The idea using the light way get the spte on x86_32 guest is from * gup_get_pte (mm/gup.c). * - * An spte tlb flush may be pending, because kvm_set_pte_rmap - * coalesces them and we are running out of the MMU lock. Therefore + * An spte tlb flush may be pending, because they are coalesced and + * we are running out of the MMU lock. Therefore * we need to protect against in-progress updates of the spte. * * Reading the spte while an update is in progress may get the old value @@ -1454,43 +1454,6 @@ static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, return __kvm_zap_rmap(kvm, rmap_head, slot); } -static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, gfn_t gfn, int level, - pte_t pte) -{ - u64 *sptep; - struct rmap_iterator iter; - bool need_flush = false; - u64 new_spte; - kvm_pfn_t new_pfn; - - WARN_ON_ONCE(pte_huge(pte)); - new_pfn = pte_pfn(pte); - -restart: - for_each_rmap_spte(rmap_head, &iter, sptep) { - need_flush = true; - - if (pte_write(pte)) { - kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); - goto restart; - } else { - new_spte = kvm_mmu_changed_pte_notifier_make_spte( - *sptep, new_pfn); - - mmu_spte_clear_track_bits(kvm, sptep); - mmu_spte_set(sptep, new_spte); - } - } - - if (need_flush && kvm_available_flush_remote_tlbs_range()) { - kvm_flush_remote_tlbs_gfn(kvm, gfn, level); - return false; - } - - return need_flush; -} - struct slot_rmap_walk_iterator { /* input fields. */ const struct kvm_memory_slot *slot; @@ -1596,19 +1559,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) return flush; } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - bool flush = false; - - if (kvm_memslots_have_rmaps(kvm)) - flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); - - if (tdp_mmu_enabled) - flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); - - return flush; -} - static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, struct kvm_memory_slot *slot, gfn_t gfn, int level, pte_t unused) diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 318135daf685..283af5b90016 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -322,22 +322,6 @@ u64 make_nonleaf_spte(u64 *child_pt, bool ad_disabled) return spte; } -u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn) -{ - u64 new_spte; - - new_spte = old_spte & ~SPTE_BASE_ADDR_MASK; - new_spte |= (u64)new_pfn << PAGE_SHIFT; - - new_spte &= ~PT_WRITABLE_MASK; - new_spte &= ~shadow_host_writable_mask; - new_spte &= ~shadow_mmu_writable_mask; - - new_spte = mark_spte_for_access_track(new_spte); - - return new_spte; -} - u64 mark_spte_for_access_track(u64 spte) { if (spte_ad_enabled(spte)) diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index 1a163aee9ec6..92da4c419171 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -511,8 +511,6 @@ static inline u64 restore_acc_track_spte(u64 spte) return spte; } -u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn); - void __init kvm_mmu_spte_module_init(void); void kvm_mmu_reset_all_pte_masks(void); diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 3627744fcab6..fbb86932b766 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1250,52 +1250,6 @@ bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) return kvm_tdp_mmu_handle_gfn(kvm, range, test_age_gfn); } -static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter, - struct kvm_gfn_range *range) -{ - u64 new_spte; - - /* Huge pages aren't expected to be modified without first being zapped. */ - WARN_ON_ONCE(pte_huge(range->arg.pte) || range->start + 1 != range->end); - - if (iter->level != PG_LEVEL_4K || - !is_shadow_present_pte(iter->old_spte)) - return false; - - /* - * Note, when changing a read-only SPTE, it's not strictly necessary to - * zero the SPTE before setting the new PFN, but doing so preserves the - * invariant that the PFN of a present * leaf SPTE can never change. - * See handle_changed_spte(). - */ - tdp_mmu_iter_set_spte(kvm, iter, SHADOW_NONPRESENT_VALUE); - - if (!pte_write(range->arg.pte)) { - new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte, - pte_pfn(range->arg.pte)); - - tdp_mmu_iter_set_spte(kvm, iter, new_spte); - } - - return true; -} - -/* - * Handle the changed_pte MMU notifier for the TDP MMU. - * data is a pointer to the new pte_t mapping the HVA specified by the MMU - * notifier. - * Returns non-zero if a flush is needed before releasing the MMU lock. - */ -bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - /* - * No need to handle the remote TLB flush under RCU protection, the - * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a - * shadow page. See the WARN on pfn_changed in handle_changed_spte(). - */ - return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); -} - /* * Remove write access from all SPTEs at or above min_level that map GFNs * [start, end). Returns true if an SPTE has been changed and the TLBs need to diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index 6e1ea04ca885..58b55e61bd33 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -31,7 +31,6 @@ bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range, bool flush); bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range); -bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, const struct kvm_memory_slot *slot, int min_level); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ab439706ea2f..8dea11701ab2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -259,7 +259,6 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu); #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER union kvm_mmu_notifier_arg { - pte_t pte; unsigned long attributes; }; @@ -273,7 +272,6 @@ struct kvm_gfn_range { bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range); -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range); #endif enum { diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h index 011fba6b5552..74e40d5d4af4 100644 --- a/include/trace/events/kvm.h +++ b/include/trace/events/kvm.h @@ -456,21 +456,6 @@ TRACE_EVENT(kvm_unmap_hva_range, __entry->start, __entry->end) ); -TRACE_EVENT(kvm_set_spte_hva, - TP_PROTO(unsigned long hva), - TP_ARGS(hva), - - TP_STRUCT__entry( - __field( unsigned long, hva ) - ), - - TP_fast_assign( - __entry->hva = hva; - ), - - TP_printk("mmu notifier set pte hva: %#016lx", __entry->hva) -); - TRACE_EVENT(kvm_age_hva, TP_PROTO(unsigned long start, unsigned long end), TP_ARGS(start, end), diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4eb8afd0b961..2fcd9979752a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -717,48 +717,6 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn return __kvm_handle_hva_range(kvm, &range).ret; } -static bool kvm_change_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - /* - * Skipping invalid memslots is correct if and only change_pte() is - * surrounded by invalidate_range_{start,end}(), which is currently - * guaranteed by the primary MMU. If that ever changes, KVM needs to - * unmap the memslot instead of skipping the memslot to ensure that KVM - * doesn't hold references to the old PFN. - */ - WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count)); - - if (range->slot->flags & KVM_MEMSLOT_INVALID) - return false; - - return kvm_set_spte_gfn(kvm, range); -} - -static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long address, - pte_t pte) -{ - struct kvm *kvm = mmu_notifier_to_kvm(mn); - const union kvm_mmu_notifier_arg arg = { .pte = pte }; - - trace_kvm_set_spte_hva(address); - - /* - * .change_pte() must be surrounded by .invalidate_range_{start,end}(). - * If mmu_invalidate_in_progress is zero, then no in-progress - * invalidations, including this one, found a relevant memslot at - * start(); rechecking memslots here is unnecessary. Note, a false - * positive (count elevated by a different invalidation) is sub-optimal - * but functionally ok. - */ - WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count)); - if (!READ_ONCE(kvm->mmu_invalidate_in_progress)) - return; - - kvm_handle_hva_range(mn, address, address + 1, arg, kvm_change_spte_gfn); -} - void kvm_mmu_invalidate_begin(struct kvm *kvm) { lockdep_assert_held_write(&kvm->mmu_lock); @@ -976,7 +934,6 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { .clear_flush_young = kvm_mmu_notifier_clear_flush_young, .clear_young = kvm_mmu_notifier_clear_young, .test_young = kvm_mmu_notifier_test_young, - .change_pte = kvm_mmu_notifier_change_pte, .release = kvm_mmu_notifier_release, }; From patchwork Fri Apr 5 11:58:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13618949 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A3BD16C6B2 for ; Fri, 5 Apr 2024 11:58:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318309; cv=none; b=kA1DOt9cfu6/ft8mnwWgPYc5ajbiGLT8ajau5myjlscekJNj9voq5U/8YGbupa6Eja6zmzhqKRXc2nOGXxLfzVHfLC3Lrrht0mNTQiEXVFF47dTIFAn8HdKATCIdAF8x/krk/LYmeX/xi9Y7Dp3feu7/jbNvSeAnAmwauUjPGfU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318309; c=relaxed/simple; bh=MVPfw12aKDAKYxBgmyfiqiiyclWrH3J9VU7NBfl7yag=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qM2V9sZcYa2vCC+oMKK2i1LRwfQGzADLHgNGC2ghNUZzmd42eBBR4KH4kUrARcxgSgZKyJhE5p8k+9fJuzuI1jSIMnYyD6qjcxOkBWvc7CVgskF9u3C806h2PEnolrvuQFsGC0MgI880QhRIEof3307QW5PbS9al0t0sSNOHWic= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=WxNkIJ4g; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WxNkIJ4g" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712318306; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PYlVlmhvJPdz+cTS0GmxjcvjKIkp+1zDoZOzzNIMhco=; b=WxNkIJ4gBKNiTmHpZ9eYEn1B2i6PBImFBxtWWWrVNl324sF+tzteAssEN1ohjY/qmLw0nC LJl3BDlqwxGD1OuWF0WvEdAQWMtH8jz+7SsD9025REfS0vwvYJxM0oMzV566X8tIDlxTJ3 kEhp0cBS547yVdY9wUBQSm9vATGpk+8= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-94-jWBq89b1PjOkiIzryzMcEA-1; Fri, 05 Apr 2024 07:58:21 -0400 X-MC-Unique: jWBq89b1PjOkiIzryzMcEA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 07BB2382C473; Fri, 5 Apr 2024 11:58:20 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 470FC40C6CB5; Fri, 5 Apr 2024 11:58:19 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Thomas Bogendoerfer , Nicholas Piggin , Anup Patel , Atish Patra , Sean Christopherson , Andrew Morton , David Hildenbrand , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH 2/4] KVM: remove unused argument of kvm_handle_hva_range() Date: Fri, 5 Apr 2024 07:58:13 -0400 Message-ID: <20240405115815.3226315-3-pbonzini@redhat.com> In-Reply-To: <20240405115815.3226315-1-pbonzini@redhat.com> References: <20240405115815.3226315-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 The only user was kvm_mmu_notifier_change_pte(), which is now gone. Signed-off-by: Paolo Bonzini Reviewed-by: Philippe Mathieu-Daudé --- virt/kvm/kvm_main.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2fcd9979752a..9701888811ad 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -595,8 +595,6 @@ static void kvm_null_fn(void) } #define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn) -static const union kvm_mmu_notifier_arg KVM_MMU_NOTIFIER_NO_ARG; - /* Iterate over each memslot intersecting [start, last] (inclusive) range */ #define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \ for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \ @@ -682,14 +680,12 @@ static __always_inline kvm_mn_ret_t __kvm_handle_hva_range(struct kvm *kvm, static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn, unsigned long start, unsigned long end, - union kvm_mmu_notifier_arg arg, gfn_handler_t handler) { struct kvm *kvm = mmu_notifier_to_kvm(mn); const struct kvm_mmu_notifier_range range = { .start = start, .end = end, - .arg = arg, .handler = handler, .on_lock = (void *)kvm_null_fn, .flush_on_ret = true, @@ -880,8 +876,7 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, { trace_kvm_age_hva(start, end); - return kvm_handle_hva_range(mn, start, end, KVM_MMU_NOTIFIER_NO_ARG, - kvm_age_gfn); + return kvm_handle_hva_range(mn, start, end, kvm_age_gfn); } static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, From patchwork Fri Apr 5 11:58:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13618952 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1DA816C6A6 for ; Fri, 5 Apr 2024 11:58:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318310; cv=none; b=exPUfEQDjBliQTp2tpqMRG3B2Rtiwgxw8QGE9H7NVy+ezqvGgXWC7uHvD/CSoyMuxif8ks7vhU29RwlEoyVc5FHSTaGjajGMGC9VF+6dFy4z2NJ0NM04KUdAuMLNVzROnkuo2ZEQgTUzI3uZC6LLFs1LQm0ZyyuOII6MA9wQzGw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318310; c=relaxed/simple; bh=hH3qcfIlDFNFXcnOAXz5nQZISUR02/h+wK8MXGjdmhw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qyp7/R6Uzz9nqHFgOMSGOcgUee+TyMx1a0liy9xF97t+qcuuL1DUhAJEcJJ1uVjN0W5/z8pJ+BlYtNIag/RWrB2txnQuNwaLT7/c/1tmvbCtjggV7Zv8a9p4FjgzC3Kl1w+/cGOBDgBuwhZCbqQCtVeySIP5va4cLtWiKUk2A9o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RkQ+DeVS; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RkQ+DeVS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712318307; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=54r2v6x4hCqSU9lpxJJX8F9xMdFOFqhWRrFs4bS58g8=; b=RkQ+DeVSLrpPt3jkvi8svCJgl1Zq954AHMnkHcy4BP/6ZDU8JF+RbP1cJStFfAbJWRc9qS Q6CS+2JUEFHY/cQnkk70XW3WZKwLNLaaxT95EaqSsSi1sk48vhDoJgbFnlXY3t+8Wwz/Y8 jlL9agajAP9MGlJZUYrPLHJEvWQFbJE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-653-1T7hKq5gPw2fRM982K2a_w-1; Fri, 05 Apr 2024 07:58:22 -0400 X-MC-Unique: 1T7hKq5gPw2fRM982K2a_w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C4A2888D0C8; Fri, 5 Apr 2024 11:58:20 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 13F6640C6CB3; Fri, 5 Apr 2024 11:58:20 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Thomas Bogendoerfer , Nicholas Piggin , Anup Patel , Atish Patra , Sean Christopherson , Andrew Morton , David Hildenbrand , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH 3/4] mmu_notifier: remove the .change_pte() callback Date: Fri, 5 Apr 2024 07:58:14 -0400 Message-ID: <20240405115815.3226315-4-pbonzini@redhat.com> In-Reply-To: <20240405115815.3226315-1-pbonzini@redhat.com> References: <20240405115815.3226315-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 The scope of set_pte_at_notify() has reduced more and more through the years. Initially, it was meant for when the change to the PTE was not bracketed by mmu_notifier_invalidate_range_{start,end}(). However, that has not been so for over ten years. During all this period the only implementation of .change_pte() was KVM and it had no actual functionality, because it was called after mmu_notifier_invalidate_range_start() zapped the secondary PTE. Now that this (nonfunctional) user of the .change_pte() callback is gone, the whole callback can be removed. For now, leave in place set_pte_at_notify() even though it is just a synonym for set_pte_at(). Signed-off-by: Paolo Bonzini Reviewed-by: David Hildenbrand --- include/linux/mmu_notifier.h | 46 ++---------------------------------- mm/mmu_notifier.c | 17 ------------- 2 files changed, 2 insertions(+), 61 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index f349e08a9dfe..8c72bf651606 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -122,15 +122,6 @@ struct mmu_notifier_ops { struct mm_struct *mm, unsigned long address); - /* - * change_pte is called in cases that pte mapping to page is changed: - * for example, when ksm remaps pte to point to a new shared page. - */ - void (*change_pte)(struct mmu_notifier *subscription, - struct mm_struct *mm, - unsigned long address, - pte_t pte); - /* * invalidate_range_start() and invalidate_range_end() must be * paired and are called only when the mmap_lock and/or the @@ -392,8 +383,6 @@ extern int __mmu_notifier_clear_young(struct mm_struct *mm, unsigned long end); extern int __mmu_notifier_test_young(struct mm_struct *mm, unsigned long address); -extern void __mmu_notifier_change_pte(struct mm_struct *mm, - unsigned long address, pte_t pte); extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r); extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r); extern void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm, @@ -439,13 +428,6 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm, return 0; } -static inline void mmu_notifier_change_pte(struct mm_struct *mm, - unsigned long address, pte_t pte) -{ - if (mm_has_notifiers(mm)) - __mmu_notifier_change_pte(mm, address, pte); -} - static inline void mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) { @@ -581,26 +563,6 @@ static inline void mmu_notifier_range_init_owner( __young; \ }) -/* - * set_pte_at_notify() sets the pte _after_ running the notifier. - * This is safe to start by updating the secondary MMUs, because the primary MMU - * pte invalidate must have already happened with a ptep_clear_flush() before - * set_pte_at_notify() has been invoked. Updating the secondary MMUs first is - * required when we change both the protection of the mapping from read-only to - * read-write and the pfn (like during copy on write page faults). Otherwise the - * old page would remain mapped readonly in the secondary MMUs after the new - * page is already writable by some CPU through the primary MMU. - */ -#define set_pte_at_notify(__mm, __address, __ptep, __pte) \ -({ \ - struct mm_struct *___mm = __mm; \ - unsigned long ___address = __address; \ - pte_t ___pte = __pte; \ - \ - mmu_notifier_change_pte(___mm, ___address, ___pte); \ - set_pte_at(___mm, ___address, __ptep, ___pte); \ -}) - #else /* CONFIG_MMU_NOTIFIER */ struct mmu_notifier_range { @@ -650,11 +612,6 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm, return 0; } -static inline void mmu_notifier_change_pte(struct mm_struct *mm, - unsigned long address, pte_t pte) -{ -} - static inline void mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) { @@ -693,7 +650,6 @@ static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm) #define ptep_clear_flush_notify ptep_clear_flush #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush #define pudp_huge_clear_flush_notify pudp_huge_clear_flush -#define set_pte_at_notify set_pte_at static inline void mmu_notifier_synchronize(void) { @@ -701,4 +657,6 @@ static inline void mmu_notifier_synchronize(void) #endif /* CONFIG_MMU_NOTIFIER */ +#define set_pte_at_notify set_pte_at + #endif /* _LINUX_MMU_NOTIFIER_H */ diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index ec3b068cbbe6..8982e6139d07 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -424,23 +424,6 @@ int __mmu_notifier_test_young(struct mm_struct *mm, return young; } -void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, - pte_t pte) -{ - struct mmu_notifier *subscription; - int id; - - id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(subscription, - &mm->notifier_subscriptions->list, hlist, - srcu_read_lock_held(&srcu)) { - if (subscription->ops->change_pte) - subscription->ops->change_pte(subscription, mm, address, - pte); - } - srcu_read_unlock(&srcu, id); -} - static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions, const struct mmu_notifier_range *range) { From patchwork Fri Apr 5 11:58:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13618950 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F22F716C863 for ; Fri, 5 Apr 2024 11:58:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318310; cv=none; b=bV4Ee7b3MV4NvkGSLJiNXT9dQrd2N7Sf9Oa8qP9lKl//1WDUY8B89TF0VR3kit2fiFxQMuN7BgUMjdKdIS1/kNtbThSb+QbmOWjhigJMmu04HykLqymKBkRr7qmlEKgiuSvhOd8AreT4s7hUzP3RM4J5uUy+lOuAZON8naDu5XY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712318310; c=relaxed/simple; bh=VOl9mQCZZBeBKTYD0q38JVa+rIW4wA9u/6sOyqn9PV4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=NsDnti9tKyMCmKbG71fT1h7htnZE9ULqT8L7AJuX/j0VodvWusQg+tT1Df0CwTPbEtv74sz/mBZGgVfVdO5Y+GiLVi7ZVJxlDYZu+G+o4/Y0lxIlLKXil8QRohbb+40z4zPzkqLGnrjoLNtqwmtXUXvftgvMicSzVqO3lY26AcU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SnfPExZf; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SnfPExZf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712318306; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bNbIAMV3AIIh+finZC0kYCtErDA0HoO+gaZWe4mDURE=; b=SnfPExZfj0WL2UxB4nml7MDopgTEIuwvknZjwbj7ouf/2C/7q2n2l10F83KNuqOffuJ4HB cZeOKxo9gefehzI8hhC6CYTajtc88D/kGCGizkbGJqnJSSuMLE7mL6rQf/AUzF4H+b2J94 h5f5jLXKcU5mZk2sZtp10/UI7j8vxP4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-216-j7EJIyIYM6OGTJqf_yp9KQ-1; Fri, 05 Apr 2024 07:58:23 -0400 X-MC-Unique: j7EJIyIYM6OGTJqf_yp9KQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 584B885CF01; Fri, 5 Apr 2024 11:58:22 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id D080D40C6CB5; Fri, 5 Apr 2024 11:58:20 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Thomas Bogendoerfer , Nicholas Piggin , Anup Patel , Atish Patra , Sean Christopherson , Andrew Morton , David Hildenbrand , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH 4/4] mm: replace set_pte_at_notify() with just set_pte_at() Date: Fri, 5 Apr 2024 07:58:15 -0400 Message-ID: <20240405115815.3226315-5-pbonzini@redhat.com> In-Reply-To: <20240405115815.3226315-1-pbonzini@redhat.com> References: <20240405115815.3226315-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 With the demise of the .change_pte() MMU notifier callback, there is no notification happening in set_pte_at_notify(). It is a synonym of set_pte_at() and can be replaced with it. Signed-off-by: Paolo Bonzini Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: David Hildenbrand --- include/linux/mmu_notifier.h | 2 -- kernel/events/uprobes.c | 5 ++--- mm/ksm.c | 4 ++-- mm/memory.c | 7 +------ mm/migrate_device.c | 8 ++------ 5 files changed, 7 insertions(+), 19 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 8c72bf651606..d39ebb10caeb 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -657,6 +657,4 @@ static inline void mmu_notifier_synchronize(void) #endif /* CONFIG_MMU_NOTIFIER */ -#define set_pte_at_notify set_pte_at - #endif /* _LINUX_MMU_NOTIFIER_H */ diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index e4834d23e1d1..f4523b95c945 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -18,7 +18,6 @@ #include #include #include /* anon_vma_prepare */ -#include /* set_pte_at_notify */ #include /* folio_free_swap */ #include /* user_enable_single_step */ #include /* notifier mechanism */ @@ -195,8 +194,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, flush_cache_page(vma, addr, pte_pfn(ptep_get(pvmw.pte))); ptep_clear_flush(vma, addr, pvmw.pte); if (new_page) - set_pte_at_notify(mm, addr, pvmw.pte, - mk_pte(new_page, vma->vm_page_prot)); + set_pte_at(mm, addr, pvmw.pte, + mk_pte(new_page, vma->vm_page_prot)); folio_remove_rmap_pte(old_folio, old_page, vma); if (!folio_mapped(old_folio)) diff --git a/mm/ksm.c b/mm/ksm.c index 8c001819cf10..108a4d167824 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1345,7 +1345,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, if (pte_write(entry)) entry = pte_wrprotect(entry); - set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry); + set_pte_at(mm, pvmw.address, pvmw.pte, entry); } *orig_pte = entry; err = 0; @@ -1447,7 +1447,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page, * See Documentation/mm/mmu_notifier.rst */ ptep_clear_flush(vma, addr, ptep); - set_pte_at_notify(mm, addr, ptep, newpte); + set_pte_at(mm, addr, ptep, newpte); folio = page_folio(page); folio_remove_rmap_pte(folio, page, vma); diff --git a/mm/memory.c b/mm/memory.c index f2bc6dd15eb8..9a6f4d8aa379 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3327,13 +3327,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) ptep_clear_flush(vma, vmf->address, vmf->pte); folio_add_new_anon_rmap(new_folio, vma, vmf->address); folio_add_lru_vma(new_folio, vma); - /* - * We call the notify macro here because, when using secondary - * mmu page tables (such as kvm shadow page tables), we want the - * new page to be mapped directly into the secondary page table. - */ BUG_ON(unshare && pte_write(entry)); - set_pte_at_notify(mm, vmf->address, vmf->pte, entry); + set_pte_at(mm, vmf->address, vmf->pte, entry); update_mmu_cache_range(vmf, vma, vmf->address, vmf->pte, 1); if (old_folio) { /* diff --git a/mm/migrate_device.c b/mm/migrate_device.c index b6c27c76e1a0..66206734b1b9 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -664,13 +664,9 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate, if (flush) { flush_cache_page(vma, addr, pte_pfn(orig_pte)); ptep_clear_flush(vma, addr, ptep); - set_pte_at_notify(mm, addr, ptep, entry); - update_mmu_cache(vma, addr, ptep); - } else { - /* No need to invalidate - it was non-present before */ - set_pte_at(mm, addr, ptep, entry); - update_mmu_cache(vma, addr, ptep); } + set_pte_at(mm, addr, ptep, entry); + update_mmu_cache(vma, addr, ptep); pte_unmap_unlock(ptep, ptl); *src = MIGRATE_PFN_MIGRATE;