Commit 3d4a5a45 authored by David Matlack's avatar David Matlack Committed by Sean Christopherson
Browse files

KVM: x86/mmu: Unnest TDP MMU helpers that allocate SPs for eager splitting 



Move the implementation of tdp_mmu_alloc_sp_for_split() to its one and
only caller to reduce unnecessary nesting and make it more clear why the
eager split loop continues after allocating a new SP.

Opportunistically drop the double-underscores from
__tdp_mmu_alloc_sp_for_split() now that its parent is gone.

No functional change intended.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20240611220512.2426439-4-dmatlack@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent e1c04f7a

arch/x86/kvm/mmu/tdp_mmu.c

+18 −30
Original line number Diff line number Diff line
@@ -1339,7 +1339,7 @@ bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, 
	return spte_set;

}



static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(void)

static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(void)

{

	struct kvm_mmu_page *sp;
@@ -1356,34 +1356,6 @@ static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(void) 
	return sp;

}



static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,

						       struct tdp_iter *iter,

						       bool shared)

{

	struct kvm_mmu_page *sp;



	kvm_lockdep_assert_mmu_lock_held(kvm, shared);



	rcu_read_unlock();



	if (shared)

		read_unlock(&kvm->mmu_lock);

	else

		write_unlock(&kvm->mmu_lock);



	iter->yielded = true;

	sp = __tdp_mmu_alloc_sp_for_split();



	if (shared)

		read_lock(&kvm->mmu_lock);

	else

		write_lock(&kvm->mmu_lock);



	rcu_read_lock();



	return sp;

}



/* Note, the caller is responsible for initializing @sp. */

static int tdp_mmu_split_huge_page(struct kvm *kvm, struct tdp_iter *iter,

				   struct kvm_mmu_page *sp, bool shared)
@@ -1454,7 +1426,22 @@ static int tdp_mmu_split_huge_pages_root(struct kvm *kvm, 
			continue;



		if (!sp) {

			sp = tdp_mmu_alloc_sp_for_split(kvm, &iter, shared);

			rcu_read_unlock();



			if (shared)

				read_unlock(&kvm->mmu_lock);

			else

				write_unlock(&kvm->mmu_lock);



			sp = tdp_mmu_alloc_sp_for_split();



			if (shared)

				read_lock(&kvm->mmu_lock);

			else

				write_lock(&kvm->mmu_lock);



			rcu_read_lock();



			if (!sp) {

				ret = -ENOMEM;

				trace_kvm_mmu_split_huge_page(iter.gfn,
@@ -1463,6 +1450,7 @@ static int tdp_mmu_split_huge_pages_root(struct kvm *kvm, 
				break;

			}



			iter.yielded = true;

			continue;

		}