KVM: x86: create mmu/ subdirectory

Preparatory work for shattering mmu.c into multiple files.  Besides making it easier
to follow, this will also make it possible to write unit tests for various parts.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 0 insertions, 265 deletions

diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c
deleted file mode 100644
index 3521e2d176f2..000000000000
--- a/arch/x86/kvm/page_track.c
+++ /dev/null
@@ -1,265 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Support KVM gust page tracking
- *
- * This feature allows us to track page access in guest. Currently, only
- * write access is tracked.
- *
- * Copyright(C) 2015 Intel Corporation.
- *
- * Author:
- *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
- */
-
-#include <linux/kvm_host.h>
-#include <linux/rculist.h>
-
-#include <asm/kvm_host.h>
-#include <asm/kvm_page_track.h>
-
-#include "mmu.h"
-
-void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
-				 struct kvm_memory_slot *dont)
-{
-	int i;
-
-	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++)
-		if (!dont || free->arch.gfn_track[i] !=
-		      dont->arch.gfn_track[i]) {
-			kvfree(free->arch.gfn_track[i]);
-			free->arch.gfn_track[i] = NULL;
-		}
-}
-
-int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
-				  unsigned long npages)
-{
-	int  i;
-
-	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++) {
-		slot->arch.gfn_track[i] =
-			kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]),
-				 GFP_KERNEL_ACCOUNT);
-		if (!slot->arch.gfn_track[i])
-			goto track_free;
-	}
-
-	return 0;
-
-track_free:
-	kvm_page_track_free_memslot(slot, NULL);
-	return -ENOMEM;
-}
-
-static inline bool page_track_mode_is_valid(enum kvm_page_track_mode mode)
-{
-	if (mode < 0 || mode >= KVM_PAGE_TRACK_MAX)
-		return false;
-
-	return true;
-}
-
-static void update_gfn_track(struct kvm_memory_slot *slot, gfn_t gfn,
-			     enum kvm_page_track_mode mode, short count)
-{
-	int index, val;
-
-	index = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL);
-
-	val = slot->arch.gfn_track[mode][index];
-
-	if (WARN_ON(val + count < 0 || val + count > USHRT_MAX))
-		return;
-
-	slot->arch.gfn_track[mode][index] += count;
-}
-
-/*
- * add guest page to the tracking pool so that corresponding access on that
- * page will be intercepted.
- *
- * It should be called under the protection both of mmu-lock and kvm->srcu
- * or kvm->slots_lock.
- *
- * @kvm: the guest instance we are interested in.
- * @slot: the @gfn belongs to.
- * @gfn: the guest page.
- * @mode: tracking mode, currently only write track is supported.
- */
-void kvm_slot_page_track_add_page(struct kvm *kvm,
-				  struct kvm_memory_slot *slot, gfn_t gfn,
-				  enum kvm_page_track_mode mode)
-{
-
-	if (WARN_ON(!page_track_mode_is_valid(mode)))
-		return;
-
-	update_gfn_track(slot, gfn, mode, 1);
-
-	/*
-	 * new track stops large page mapping for the
-	 * tracked page.
-	 */
-	kvm_mmu_gfn_disallow_lpage(slot, gfn);
-
-	if (mode == KVM_PAGE_TRACK_WRITE)
-		if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn))
-			kvm_flush_remote_tlbs(kvm);
-}
-EXPORT_SYMBOL_GPL(kvm_slot_page_track_add_page);
-
-/*
- * remove the guest page from the tracking pool which stops the interception
- * of corresponding access on that page. It is the opposed operation of
- * kvm_slot_page_track_add_page().
- *
- * It should be called under the protection both of mmu-lock and kvm->srcu
- * or kvm->slots_lock.
- *
- * @kvm: the guest instance we are interested in.
- * @slot: the @gfn belongs to.
- * @gfn: the guest page.
- * @mode: tracking mode, currently only write track is supported.
- */
-void kvm_slot_page_track_remove_page(struct kvm *kvm,
-				     struct kvm_memory_slot *slot, gfn_t gfn,
-				     enum kvm_page_track_mode mode)
-{
-	if (WARN_ON(!page_track_mode_is_valid(mode)))
-		return;
-
-	update_gfn_track(slot, gfn, mode, -1);
-
-	/*
-	 * allow large page mapping for the tracked page
-	 * after the tracker is gone.
-	 */
-	kvm_mmu_gfn_allow_lpage(slot, gfn);
-}
-EXPORT_SYMBOL_GPL(kvm_slot_page_track_remove_page);
-
-/*
- * 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;
-	int index;
-
-	if (WARN_ON(!page_track_mode_is_valid(mode)))
-		return false;
-
-	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
-	if (!slot)
-		return false;
-
-	index = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL);
-	return !!READ_ONCE(slot->arch.gfn_track[mode][index]);
-}
-
-void kvm_page_track_cleanup(struct kvm *kvm)
-{
-	struct kvm_page_track_notifier_head *head;
-
-	head = &kvm->arch.track_notifier_head;
-	cleanup_srcu_struct(&head->track_srcu);
-}
-
-void kvm_page_track_init(struct kvm *kvm)
-{
-	struct kvm_page_track_notifier_head *head;
-
-	head = &kvm->arch.track_notifier_head;
-	init_srcu_struct(&head->track_srcu);
-	INIT_HLIST_HEAD(&head->track_notifier_list);
-}
-
-/*
- * register the notifier so that event interception for the tracked guest
- * pages can be received.
- */
-void
-kvm_page_track_register_notifier(struct kvm *kvm,
-				 struct kvm_page_track_notifier_node *n)
-{
-	struct kvm_page_track_notifier_head *head;
-
-	head = &kvm->arch.track_notifier_head;
-
-	spin_lock(&kvm->mmu_lock);
-	hlist_add_head_rcu(&n->node, &head->track_notifier_list);
-	spin_unlock(&kvm->mmu_lock);
-}
-EXPORT_SYMBOL_GPL(kvm_page_track_register_notifier);
-
-/*
- * stop receiving the event interception. It is the opposed operation of
- * kvm_page_track_register_notifier().
- */
-void
-kvm_page_track_unregister_notifier(struct kvm *kvm,
-				   struct kvm_page_track_notifier_node *n)
-{
-	struct kvm_page_track_notifier_head *head;
-
-	head = &kvm->arch.track_notifier_head;
-
-	spin_lock(&kvm->mmu_lock);
-	hlist_del_rcu(&n->node);
-	spin_unlock(&kvm->mmu_lock);
-	synchronize_srcu(&head->track_srcu);
-}
-EXPORT_SYMBOL_GPL(kvm_page_track_unregister_notifier);
-
-/*
- * Notify the node that write access is intercepted and write emulation is
- * finished at this time.
- *
- * The node should figure out if the written page is the one that node is
- * interested in by itself.
- */
-void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
-			  int bytes)
-{
-	struct kvm_page_track_notifier_head *head;
-	struct kvm_page_track_notifier_node *n;
-	int idx;
-
-	head = &vcpu->kvm->arch.track_notifier_head;
-
-	if (hlist_empty(&head->track_notifier_list))
-		return;
-
-	idx = srcu_read_lock(&head->track_srcu);
-	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
-		if (n->track_write)
-			n->track_write(vcpu, gpa, new, bytes, n);
-	srcu_read_unlock(&head->track_srcu, idx);
-}
-
-/*
- * Notify the node that memory slot is being removed or moved so that it can
- * drop write-protection for the pages in the memory slot.
- *
- * The node should figure out it has any write-protected pages in this slot
- * by itself.
- */
-void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
-{
-	struct kvm_page_track_notifier_head *head;
-	struct kvm_page_track_notifier_node *n;
-	int idx;
-
-	head = &kvm->arch.track_notifier_head;
-
-	if (hlist_empty(&head->track_notifier_list))
-		return;
-
-	idx = srcu_read_lock(&head->track_srcu);
-	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
-		if (n->track_flush_slot)
-			n->track_flush_slot(kvm, slot, n);
-	srcu_read_unlock(&head->track_srcu, idx);
-}