Unverified Commit a6281729 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!5445 KVM: x86/mmu: Don't advance iterator after restart due to yielding 

Merge Pull Request from: @ci-robot 
 
PR sync from: Liu Shixin <liushixin2@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/LTKVFW6EPBMA3E3A3ORQVJ5JLS3MBQFI/ 
 
https://gitee.com/src-openeuler/kernel/issues/I95REM 
 
Link:https://gitee.com/openeuler/kernel/pulls/5445

 

Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarKevin Zhu <zhukeqian1@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents 7d7a9cb8 6bf8f6af

arch/x86/kvm/mmu/tdp_iter.c

+6 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ static gfn_t round_gfn_for_level(gfn_t gfn, int level) 
 */

void tdp_iter_restart(struct tdp_iter *iter)

{

	iter->yielded = false;

	iter->yielded_gfn = iter->next_last_level_gfn;

	iter->level = iter->root_level;
@@ -160,6 +161,11 @@ static bool try_step_up(struct tdp_iter *iter) 
 */

void tdp_iter_next(struct tdp_iter *iter)

{

	if (iter->yielded) {

		tdp_iter_restart(iter);

		return;

	}



	if (try_step_down(iter))

		return;

arch/x86/kvm/mmu/tdp_iter.h

+6 −0
Original line number Diff line number Diff line
@@ -45,6 +45,12 @@ struct tdp_iter { 
	 * iterator walks off the end of the paging structure.

	 */

	bool valid;

	/*

	 * True if KVM dropped mmu_lock and yielded in the middle of a walk, in

	 * which case tdp_iter_next() needs to restart the walk at the root

	 * level instead of advancing to the next entry.

	 */

	bool yielded;

};



/*

arch/x86/kvm/mmu/tdp_mmu.c

+16 −13
Original line number Diff line number Diff line
@@ -516,6 +516,8 @@ static inline bool tdp_mmu_set_spte_atomic_no_dirty_log(struct kvm *kvm, 
							struct tdp_iter *iter,

							u64 new_spte)

{

	WARN_ON_ONCE(iter->yielded);



	lockdep_assert_held_read(&kvm->mmu_lock);



	/*
@@ -601,6 +603,8 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, 
				      u64 new_spte, bool record_acc_track,

				      bool record_dirty_log)

{

	WARN_ON_ONCE(iter->yielded);



	lockdep_assert_held_write(&kvm->mmu_lock);



	/*
@@ -666,18 +670,19 @@ static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm, 
 * If this function should yield and flush is set, it will perform a remote

 * TLB flush before yielding.

 *

 * If this function yields, it will also reset the tdp_iter's walk over the

 * paging structure and the calling function should skip to the next

 * iteration to allow the iterator to continue its traversal from the

 * paging structure root.

 * If this function yields, iter->yielded is set and the caller must skip to

 * the next iteration, where tdp_iter_next() will reset the tdp_iter's walk

 * over the paging structures to allow the iterator to continue its traversal

 * from the paging structure root.

 *

 * Return true if this function yielded and the iterator's traversal was reset.

 * Return false if a yield was not needed.

 * Returns true if this function yielded.

 */

static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,

					     struct tdp_iter *iter, bool flush,

					     bool shared)

static inline bool __must_check tdp_mmu_iter_cond_resched(struct kvm *kvm,

							  struct tdp_iter *iter,

							  bool flush, bool shared)

{

	WARN_ON(iter->yielded);



	/* Ensure forward progress has been made before yielding. */

	if (iter->next_last_level_gfn == iter->yielded_gfn)

		return false;
@@ -697,12 +702,10 @@ static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm, 


		WARN_ON(iter->gfn > iter->next_last_level_gfn);



		tdp_iter_restart(iter);



		return true;

		iter->yielded = true;

	}



	return false;

	return iter->yielded;

}



/*