Commit 9be4591b authored by Sean Christopherson's avatar Sean Christopherson Committed by Yu Zhang
Browse files

KVM: x86/mmu: Store the address space ID in the TDP iterator 

mainline inclusion
from mainline-v5.12-rc4
commit 08889894
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I7S3VQ
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=08889894cc82bc3b213bdb192f274358e5a6b78d



----------------------------------------------------------------------

Store the address space ID in the TDP iterator so that it can be
retrieved without having to bounce through the root shadow page.  This
streamlines the code and fixes a Sparse warning about not properly using
rcu_dereference() when grabbing the ID from the root on the fly.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20210315233803.2706477-5-bgardon@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarYu Zhang <yu.c.zhang@linux.intel.com>
parent 3205877a

arch/x86/kvm/mmu/mmu_internal.h

+5 −0
Original line number Diff line number Diff line
@@ -78,6 +78,11 @@ static inline struct kvm_mmu_page *sptep_to_sp(u64 *sptep) 
	return to_shadow_page(__pa(sptep));

}



static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)

{

	return sp->role.smm ? 1 : 0;

}



static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu)

{

	/*

arch/x86/kvm/mmu/tdp_iter.c

+1 −5
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level, 
	iter->root_level = root_level;

	iter->min_level = min_level;

	iter->pt_path[iter->root_level - 1] = (tdp_ptep_t)root_pt;

	iter->as_id = kvm_mmu_page_as_id(sptep_to_sp(root_pt));



	tdp_iter_restart(iter);

}
@@ -169,8 +170,3 @@ void tdp_iter_next(struct tdp_iter *iter) 
	iter->valid = false;

}

tdp_ptep_t tdp_iter_root_pt(struct tdp_iter *iter)

{

	return iter->pt_path[iter->root_level - 1];

}

arch/x86/kvm/mmu/tdp_iter.h

+2 −1
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ struct tdp_iter { 
	int min_level;

	/* The iterator's current level within the paging structure */

	int level;

	/* The address space ID, i.e. SMM vs. regular. */

	int as_id;

	/* A snapshot of the value at sptep */

	u64 old_spte;

	/*
@@ -62,7 +64,6 @@ tdp_ptep_t spte_to_child_pt(u64 pte, int level); 
void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,

		    int min_level, gfn_t next_last_level_gfn);

void tdp_iter_next(struct tdp_iter *iter);

tdp_ptep_t tdp_iter_root_pt(struct tdp_iter *iter);

void tdp_iter_restart(struct tdp_iter *iter);



#endif /* __KVM_X86_MMU_TDP_ITER_H */

arch/x86/kvm/mmu/tdp_mmu.c

+5 −18
Original line number Diff line number Diff line
@@ -203,11 +203,6 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 
				u64 old_spte, u64 new_spte, int level,

				bool shared);



static int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)

{

	return sp->role.smm ? 1 : 0;

}



static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)

{

	bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
@@ -497,10 +492,6 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm, 
					   struct tdp_iter *iter,

					   u64 new_spte)

{

	u64 *root_pt = tdp_iter_root_pt(iter);

	struct kvm_mmu_page *root = sptep_to_sp(root_pt);

	int as_id = kvm_mmu_page_as_id(root);



	lockdep_assert_held_read(&kvm->mmu_lock);



	/*
@@ -514,8 +505,8 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm, 
		      new_spte) != iter->old_spte)

		return false;



	handle_changed_spte(kvm, as_id, iter->gfn, iter->old_spte, new_spte,

			    iter->level, true);

	handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,

			    new_spte, iter->level, true);



	return true;

}
@@ -569,10 +560,6 @@ 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)

{

	tdp_ptep_t root_pt = tdp_iter_root_pt(iter);

	struct kvm_mmu_page *root = sptep_to_sp(root_pt);

	int as_id = kvm_mmu_page_as_id(root);



	lockdep_assert_held_write(&kvm->mmu_lock);



	/*
@@ -586,13 +573,13 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, 


	WRITE_ONCE(*rcu_dereference(iter->sptep), new_spte);



	__handle_changed_spte(kvm, as_id, iter->gfn, iter->old_spte, new_spte,

			      iter->level, false);

	__handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,

			      new_spte, iter->level, false);

	if (record_acc_track)

		handle_changed_spte_acc_track(iter->old_spte, new_spte,

					      iter->level);

	if (record_dirty_log)

		handle_changed_spte_dirty_log(kvm, as_id, iter->gfn,

		handle_changed_spte_dirty_log(kvm, iter->as_id, iter->gfn,

					      iter->old_spte, new_spte,

					      iter->level);

}