Commit 89c0fd49 authored by Ben Gardon's avatar Ben Gardon Committed by Paolo Bonzini
Browse files

kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU 

Attach struct kvm_mmu_pages to every page in the TDP MMU to track
metadata, facilitate NX reclaim, and enable inproved parallelism of MMU
operations in future patches.

Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.

This series can be viewed in Gerrit at:
	https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538



Signed-off-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-12-bgardon@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent bb18842e

arch/x86/include/asm/kvm_host.h

+4 −0
Original line number Diff line number Diff line
@@ -1004,7 +1004,11 @@ struct kvm_arch { 
	 * operations.

	 */

	bool tdp_mmu_enabled;



	/* List of struct tdp_mmu_pages being used as roots */

	struct list_head tdp_mmu_roots;

	/* List of struct tdp_mmu_pages not being used as roots */

	struct list_head tdp_mmu_pages;

};



struct kvm_vm_stat {

arch/x86/kvm/mmu/tdp_mmu.c

+10 −3
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ void kvm_mmu_init_tdp_mmu(struct kvm *kvm) 
	kvm->arch.tdp_mmu_enabled = true;



	INIT_LIST_HEAD(&kvm->arch.tdp_mmu_roots);

	INIT_LIST_HEAD(&kvm->arch.tdp_mmu_pages);

}



void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
@@ -169,6 +170,7 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 
	bool is_leaf = is_present && is_last_spte(new_spte, level);

	bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);

	u64 *pt;

	struct kvm_mmu_page *sp;

	u64 old_child_spte;

	int i;
@@ -234,6 +236,9 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 
	 */

	if (was_present && !was_leaf && (pfn_changed || !is_present)) {

		pt = spte_to_child_pt(old_spte, level);

		sp = sptep_to_sp(pt);



		list_del(&sp->link);



		for (i = 0; i < PT64_ENT_PER_PAGE; i++) {

			old_child_spte = READ_ONCE(*(pt + i));
@@ -247,6 +252,7 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 
						   KVM_PAGES_PER_HPAGE(level));



		free_page((unsigned long)pt);

		kmem_cache_free(mmu_page_header_cache, sp);

	}

}
@@ -424,8 +430,7 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 
	bool huge_page_disallowed = exec && nx_huge_page_workaround_enabled;

	struct kvm_mmu *mmu = vcpu->arch.mmu;

	struct tdp_iter iter;

	struct kvm_mmu_memory_cache *pf_pt_cache =

			&vcpu->arch.mmu_shadow_page_cache;

	struct kvm_mmu_page *sp;

	u64 *child_pt;

	u64 new_spte;

	int ret;
@@ -471,7 +476,9 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 
		}



		if (!is_shadow_present_pte(iter.old_spte)) {

			child_pt = kvm_mmu_memory_cache_alloc(pf_pt_cache);

			sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level);

			list_add(&sp->link, &vcpu->kvm->arch.tdp_mmu_pages);

			child_pt = sp->spt;

			clear_page(child_pt);

			new_spte = make_nonleaf_spte(child_pt,

						     !shadow_accessed_mask);

CRA Git | Maintained and supported by SUSTech CRA and CCSE