[PATCH v5 1/6] KVM: arm64: Use a variable for the canonical IPA in kvm_s2_fault_map()

[Wei-Lin Chang]

Create a variable to store the canonical IPA, instead of calculating it
when needed. This will be useful when we need to use the canonical IPA
for guest stage-2 tracking later.

Signed-off-by: Wei-Lin Chang <weilin.chang at arm.com>
---
 arch/arm64/kvm/mmu.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 6c941aaa10c6..336dd8f7e8ab 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -2021,6 +2021,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
 	bool writable = prot & KVM_PGTABLE_PROT_W;
 	struct kvm *kvm = s2fd->vcpu->kvm;
+	phys_addr_t canonical_ipa;
 	struct kvm_pgtable *pgt;
 	long perm_fault_granule;
 	long mapping_size;
@@ -2039,6 +2040,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 	mapping_size = s2vi->vma_pagesize;
 	pfn = s2vi->pfn;
 	gfn = s2vi->gfn;
+	canonical_ipa = gfn_to_gpa(get_canonical_gfn(s2fd, s2vi));
 
 	/*
 	 * If we are not forced to use page mapping, check if we are
@@ -2057,6 +2059,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 				goto out_unlock;
 			}
 		}
+		canonical_ipa = ALIGN_DOWN(canonical_ipa, mapping_size);
 	}
 
 	if (!perm_fault_granule && !s2vi->map_non_cacheable && kvm_has_mte(kvm))
@@ -2090,11 +2093,9 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 	 * making sure we adjust the canonical IPA if the mapping size has
 	 * been updated (via a THP upgrade, for example).
 	 */
-	if (writable && !ret) {
-		phys_addr_t ipa = gfn_to_gpa(get_canonical_gfn(s2fd, s2vi));
-		ipa &= ~(mapping_size - 1);
-		mark_page_dirty_in_slot(kvm, s2fd->memslot, gpa_to_gfn(ipa));
-	}
+	if (writable && !ret)
+		mark_page_dirty_in_slot(kvm, s2fd->memslot,
+					gpa_to_gfn(canonical_ipa));
 
 	if (ret != -EAGAIN)
 		return ret;
-- 
2.43.0