[PATCH v2 13/30] KVM: arm64: Clean up control flow in kvm_s2_fault_map()

[Marc Zyngier]

From: Fuad Tabba <tabba at google.com>

Clean up the KVM MMU lock retry loop by pre-assigning the error code.
Add clear braces to the THP adjustment integration for readability, and
safely unnest the transparent hugepage logic branches.

Signed-off-by: Fuad Tabba <tabba at google.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/mmu.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index ee2a548999b1b..c6cd6ce5254be 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1897,10 +1897,9 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache)
 
 	kvm_fault_lock(kvm);
 	pgt = fault->vcpu->arch.hw_mmu->pgt;
-	if (mmu_invalidate_retry(kvm, fault->mmu_seq)) {
-		ret = -EAGAIN;
+	ret = -EAGAIN;
+	if (mmu_invalidate_retry(kvm, fault->mmu_seq))
 		goto out_unlock;
-	}
 
 	/*
 	 * If we are not forced to use page mapping, check if we are
@@ -1908,16 +1907,17 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache)
 	 */
 	if (fault->vma_pagesize == PAGE_SIZE &&
 	    !(fault->force_pte || fault->s2_force_noncacheable)) {
-		if (fault->fault_is_perm && fault->fault_granule > PAGE_SIZE)
+		if (fault->fault_is_perm && fault->fault_granule > PAGE_SIZE) {
 			fault->vma_pagesize = fault->fault_granule;
-		else
+		} else {
 			fault->vma_pagesize = transparent_hugepage_adjust(kvm, fault->memslot,
 									  fault->hva, &fault->pfn,
 									  &fault->fault_ipa);
 
-		if (fault->vma_pagesize < 0) {
-			ret = fault->vma_pagesize;
-			goto out_unlock;
+			if (fault->vma_pagesize < 0) {
+				ret = fault->vma_pagesize;
+				goto out_unlock;
+			}
 		}
 	}
 
@@ -1951,7 +1951,9 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache)
 	if (fault->writable && !ret)
 		mark_page_dirty_in_slot(kvm, fault->memslot, fault->gfn);
 
-	return ret != -EAGAIN ? ret : 0;
+	if (ret != -EAGAIN)
+		return ret;
+	return 0;
 }
 
 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
-- 
2.47.3