Commit 2a8c0ebd authored by Like Xu's avatar Like Xu Committed by Yu Zhang
Browse files

KVM: x86/mmu: Move the lockdep_assert of mmu_lock to inside clear_dirty_pt_masked() 

mainline inclusion
from mainline-v6.5-rc1
commit 91303f80
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I9HH9U
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=91303f800e76517d1e96d47dec290c5d5dbf1230



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

Move the lockdep_assert_held_write(&kvm->mmu_lock) from the only one caller
kvm_tdp_mmu_clear_dirty_pt_masked() to inside clear_dirty_pt_masked().

This change makes it more obvious why it's safe for clear_dirty_pt_masked()
to use the non-atomic (for non-volatile SPTEs) tdp_mmu_clear_spte_bits()
helper. for_each_tdp_mmu_root() does its own lockdep, so the only "loss"
in lockdep coverage is if the list is completely empty.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarLike Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230627042639.12636-1-likexu@tencent.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarYu Zhang <yu.c.zhang@linux.intel.com>
parent 4b575e0d

arch/x86/kvm/mmu/tdp_mmu.c

+2 −1
Original line number Diff line number Diff line
@@ -1612,6 +1612,8 @@ static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root, 
						   shadow_dirty_mask;

	struct tdp_iter iter;



	lockdep_assert_held_write(&kvm->mmu_lock);



	rcu_read_lock();



	tdp_root_for_each_leaf_pte(iter, root, gfn + __ffs(mask),
@@ -1658,7 +1660,6 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm, 
{

	struct kvm_mmu_page *root;



	lockdep_assert_held_write(&kvm->mmu_lock);

	for_each_tdp_mmu_root(kvm, root, slot->as_id)

		clear_dirty_pt_masked(kvm, root, gfn, mask, wrprot);

}