[v3,30/31] KVM: x86/mmu: Avoid memslot lookup in make_spte and mmu_try_to_unsync_pages

Message ID	20210924163152.289027-31-pbonzini@redhat.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Paolo Bonzini <pbonzini@redhat.com> To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: dmatlack@google.com, seanjc@google.com Subject: [PATCH v3 30/31] KVM: x86/mmu: Avoid memslot lookup in make_spte and mmu_try_to_unsync_pages Date: Fri, 24 Sep 2021 12:31:51 -0400 Message-Id: <20210924163152.289027-31-pbonzini@redhat.com> In-Reply-To: <20210924163152.289027-1-pbonzini@redhat.com> References: <20210924163152.289027-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	KVM: x86: pass arguments on the page fault path via struct kvm_page_fault \| expand [v3,00/31] KVM: x86: pass arguments on the page fault path via struct kvm_page_fault [v3,01/31] KVM: MMU: pass unadulterated gpa to direct_page_fault [v3,02/31] KVM: MMU: Introduce struct kvm_page_fault [v3,03/31] KVM: MMU: change mmu->page_fault() arguments to kvm_page_fault [v3,04/31] KVM: MMU: change direct_page_fault() arguments to kvm_page_fault [v3,05/31] KVM: MMU: change page_fault_handle_page_track() arguments to kvm_page_fault [v3,06/31] KVM: MMU: change kvm_faultin_pfn() arguments to kvm_page_fault [v3,07/31] KVM: MMU: change handle_abnormal_pfn() arguments to kvm_page_fault [v3,08/31] KVM: MMU: change __direct_map() arguments to kvm_page_fault [v3,09/31] KVM: MMU: change FNAME(fetch)() arguments to kvm_page_fault [v3,10/31] KVM: MMU: change kvm_tdp_mmu_map() arguments to kvm_page_fault [v3,11/31] KVM: MMU: change tdp_mmu_map_handle_target_level() arguments to kvm_page_fault [v3,12/31] KVM: MMU: change fast_page_fault() arguments to kvm_page_fault [v3,13/31] KVM: MMU: change kvm_mmu_hugepage_adjust() arguments to kvm_page_fault [v3,14/31] KVM: MMU: change disallowed_hugepage_adjust() arguments to kvm_page_fault [v3,15/31] KVM: MMU: change tracepoints arguments to kvm_page_fault [v3,16/31] KVM: x86/mmu: Verify shadow walk doesn't terminate early in page faults [v3,17/31] KVM: x86/mmu: Fold rmap_recycle into rmap_add [v3,18/31] KVM: MMU: mark page dirty in make_spte [v3,19/31] KVM: MMU: unify tdp_mmu_map_set_spte_atomic and tdp_mmu_set_spte_atomic_no_dirty_log [v3,20/31] KVM: x86/mmu: Pass the memslot around via struct kvm_page_fault [v3,21/31] KVM: x86/mmu: Avoid memslot lookup in page_fault_handle_page_track [v3,22/31] KVM: MMU: inline set_spte in mmu_set_spte [v3,23/31] KVM: MMU: inline set_spte in FNAME(sync_page) [v3,24/31] KVM: MMU: clean up make_spte return value [v3,25/31] KVM: MMU: remove unnecessary argument to mmu_set_spte [v3,26/31] KVM: MMU: set ad_disabled in TDP MMU role [v3,27/31] KVM: MMU: pass kvm_mmu_page struct to make_spte [v3,28/31] KVM: MMU: pass struct kvm_page_fault to mmu_set_spte [v3,29/31] KVM: x86/mmu: Avoid memslot lookup in rmap_add [v3,30/31] KVM: x86/mmu: Avoid memslot lookup in make_spte and mmu_try_to_unsync_pages [v3,31/31] KVM: MMU: make spte an in-out argument in make_spte

diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index 9cd9230e5cc8..5c12f97ce934 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -59,8 +59,6 @@ void kvm_slot_page_track_add_page(struct kvm *kvm, void kvm_slot_page_track_remove_page(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn, enum kvm_page_track_mode mode); -bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn, - enum kvm_page_track_mode mode); bool kvm_slot_page_track_is_active(struct kvm_memory_slot *slot, gfn_t gfn, enum kvm_page_track_mode mode); diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 7ff2c6c896a8..91292009780a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2572,8 +2572,8 @@ static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must * be write-protected. */ -int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync, - bool speculative) +int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, + gfn_t gfn, bool can_unsync, bool speculative) { struct kvm_mmu_page *sp; bool locked = false; @@ -2583,7 +2583,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync, * track machinery is used to write-protect upper-level shadow pages, * i.e. this guards the role.level == 4K assertion below! */ - if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE)) + if (kvm_slot_page_track_is_active(slot, gfn, KVM_PAGE_TRACK_WRITE)) return -EPERM; /* @@ -2719,7 +2719,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, was_rmapped = 1; } - wrprot = make_spte(vcpu, sp, pte_access, gfn, pfn, *sptep, speculative, + wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, speculative, true, host_writable, &spte); if (*sptep == spte) { diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 94f4e754facb..585146a712d2 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -118,8 +118,8 @@ static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu) kvm_x86_ops.cpu_dirty_log_size; } -int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync, - bool speculative); +int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, + gfn_t gfn, bool can_unsync, bool speculative); void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn); void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn); diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 859800f7bb95..16e7176c97a5 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -136,6 +136,9 @@ void kvm_slot_page_track_remove_page(struct kvm *kvm, } EXPORT_SYMBOL_GPL(kvm_slot_page_track_remove_page); +/* + * check if the corresponding access on the specified guest page is tracked. + */ bool kvm_slot_page_track_is_active(struct kvm_memory_slot *slot, gfn_t gfn, enum kvm_page_track_mode mode) { @@ -151,17 +154,6 @@ bool kvm_slot_page_track_is_active(struct kvm_memory_slot *slot, gfn_t gfn, return !!READ_ONCE(slot->arch.gfn_track[mode][index]); } -/* - * check if the corresponding access on the specified guest page is tracked. - */ -bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn, - enum kvm_page_track_mode mode) -{ - struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); - - return kvm_slot_page_track_is_active(slot, gfn, mode); -} - void kvm_page_track_cleanup(struct kvm *kvm) { struct kvm_page_track_notifier_head *head; diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 44361f7e70c8..d8889e02c4b7 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -1091,6 +1091,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) for (i = 0; i < PT64_ENT_PER_PAGE; i++) { u64 *sptep, spte; + struct kvm_memory_slot *slot; unsigned pte_access; pt_element_t gpte; gpa_t pte_gpa; @@ -1127,7 +1128,8 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) sptep = &sp->spt[i]; spte = *sptep; host_writable = spte & shadow_host_writable_mask; - make_spte(vcpu, sp, pte_access, gfn, + slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); + make_spte(vcpu, sp, slot, pte_access, gfn, spte_to_pfn(spte), spte, true, false, host_writable, &spte); diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 2c5c14fbfbe9..871f6114b0fa 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -90,6 +90,7 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) } bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, + struct kvm_memory_slot *slot, unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool speculative, bool can_unsync, bool host_writable, u64 *new_spte) @@ -160,7 +161,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, * e.g. it's write-tracked (upper-level SPs) or has one or more * shadow pages and unsync'ing pages is not allowed. */ - if (mmu_try_to_unsync_pages(vcpu, gfn, can_unsync, speculative)) { + if (mmu_try_to_unsync_pages(vcpu, slot, gfn, can_unsync, speculative)) { pgprintk("%s: found shadow page for %llx, marking ro\n", __func__, gfn); wrprot = true; @@ -180,8 +181,11 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, "spte = 0x%llx, level = %d, rsvd bits = 0x%llx", spte, level, get_rsvd_bits(&vcpu->arch.mmu->shadow_zero_check, spte, level)); - if (spte & PT_WRITABLE_MASK) - kvm_vcpu_mark_page_dirty(vcpu, gfn); + if ((spte & PT_WRITABLE_MASK) && kvm_slot_dirty_track_enabled(slot)) { + /* Enforced by kvm_mmu_hugepage_adjust. */ + WARN_ON(level > PG_LEVEL_4K); + mark_page_dirty_in_slot(vcpu->kvm, slot, gfn); + } *new_spte = spte; return wrprot; diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index cbb02a961ac2..7c0b09461349 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -335,6 +335,7 @@ static inline u64 get_mmio_spte_generation(u64 spte) } bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, + struct kvm_memory_slot *slot, unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool speculative, bool can_unsync, bool host_writable, u64 *new_spte); diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 6dbf28924bc2..953f24ded6bc 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -906,7 +906,7 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, if (unlikely(!fault->slot)) new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL); else - wrprot = make_spte(vcpu, sp, ACC_ALL, iter->gfn, + wrprot = make_spte(vcpu, sp, fault->slot, ACC_ALL, iter->gfn, fault->pfn, iter->old_spte, fault->prefault, true, fault->map_writable, &new_spte);

[v3,30/31] KVM: x86/mmu: Avoid memslot lookup in make_spte and mmu_try_to_unsync_pages

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