This is a note to let you know that I've just added the patch titled KVM: x86/mmu: Factor out functions to add/remove TDP MMU pages to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-x86-mmu-factor-out-functions-to-add-remove-tdp-m.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 984759b7ac6f1b165b54e36b1ef607742868c136 Author: Ben Gardon <bgardon@xxxxxxxxxx> Date: Tue Feb 2 10:57:25 2021 -0800 KVM: x86/mmu: Factor out functions to add/remove TDP MMU pages [ Upstream commit a9442f594147f95307f691cfba0c31e25dc79b9d ] Move the work of adding and removing TDP MMU pages to/from "secondary" data structures to helper functions. These functions will be built on in future commits to enable MMU operations to proceed (mostly) in parallel. No functional change expected. Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx> Message-Id: <20210202185734.1680553-20-bgardon@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 4a2b8844f00f..bc49a5b90086 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -262,6 +262,39 @@ static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn, } } +/** + * tdp_mmu_link_page - Add a new page to the list of pages used by the TDP MMU + * + * @kvm: kvm instance + * @sp: the new page + * @account_nx: This page replaces a NX large page and should be marked for + * eventual reclaim. + */ +static void tdp_mmu_link_page(struct kvm *kvm, struct kvm_mmu_page *sp, + bool account_nx) +{ + lockdep_assert_held_write(&kvm->mmu_lock); + + list_add(&sp->link, &kvm->arch.tdp_mmu_pages); + if (account_nx) + account_huge_nx_page(kvm, sp); +} + +/** + * tdp_mmu_unlink_page - Remove page from the list of pages used by the TDP MMU + * + * @kvm: kvm instance + * @sp: the page to be removed + */ +static void tdp_mmu_unlink_page(struct kvm *kvm, struct kvm_mmu_page *sp) +{ + lockdep_assert_held_write(&kvm->mmu_lock); + + list_del(&sp->link); + if (sp->lpage_disallowed) + unaccount_huge_nx_page(kvm, sp); +} + /** * handle_removed_tdp_mmu_page - handle a pt removed from the TDP structure * @@ -281,10 +314,7 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, u64 *pt) trace_kvm_mmu_prepare_zap_page(sp); - list_del(&sp->link); - - if (sp->lpage_disallowed) - unaccount_huge_nx_page(kvm, sp); + tdp_mmu_unlink_page(kvm, sp); for (i = 0; i < PT64_ENT_PER_PAGE; i++) { old_child_spte = READ_ONCE(*(pt + i)); @@ -706,15 +736,16 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (!is_shadow_present_pte(iter.old_spte)) { sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level); - list_add(&sp->link, &vcpu->kvm->arch.tdp_mmu_pages); child_pt = sp->spt; + + tdp_mmu_link_page(vcpu->kvm, sp, + huge_page_disallowed && + req_level >= iter.level); + new_spte = make_nonleaf_spte(child_pt, !shadow_accessed_mask); trace_kvm_mmu_get_page(sp, true); - if (huge_page_disallowed && req_level >= iter.level) - account_huge_nx_page(vcpu->kvm, sp); - tdp_mmu_set_spte(vcpu->kvm, &iter, new_spte); } }