[v12,40/84] KVM: x86/mmu: Add helper to "finish" handling a guest page fault

Commit Message

Sean Christopherson July 26, 2024, 11:51 p.m. UTC

Add a helper to finish/complete the handling of a guest page, e.g. to
mark the pages accessed and put any held references.  In the near
future, this will allow improving the logic without having to copy+paste
changes into all page fault paths.  And in the less near future, will
allow sharing the "finish" API across all architectures.

No functional change intended.

Signed-off-by: Sean Christopherson <[e-mail]>
---
 arch/x86/kvm/mmu/mmu.c         | 12 +++++++++---
 arch/x86/kvm/mmu/paging_tmpl.h |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e76f64f55c4a..1cdd67707461 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4311,6 +4311,12 @@  static u8 kvm_max_private_mapping_level(struct kvm *kvm, kvm_pfn_t pfn,
 	return req_max_level;
 }
 
+static void kvm_mmu_finish_page_fault(struct kvm_vcpu *vcpu,
+				      struct kvm_page_fault *fault, int r)
+{
+	kvm_release_pfn_clean(fault->pfn);
+}
+
 static int kvm_mmu_faultin_pfn_private(struct kvm_vcpu *vcpu,
 				       struct kvm_page_fault *fault)
 {
@@ -4476,7 +4482,7 @@  static int kvm_mmu_faultin_pfn(struct kvm_vcpu *vcpu,
 	 * mmu_lock is acquired.
 	 */
 	if (mmu_invalidate_retry_gfn_unsafe(vcpu->kvm, fault->mmu_seq, fault->gfn)) {
-		kvm_release_pfn_clean(fault->pfn);
+		kvm_mmu_finish_page_fault(vcpu, fault, RET_PF_RETRY);
 		return RET_PF_RETRY;
 	}
 
@@ -4552,8 +4558,8 @@  static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	r = direct_map(vcpu, fault);
 
 out_unlock:
+	kvm_mmu_finish_page_fault(vcpu, fault, r);
 	write_unlock(&vcpu->kvm->mmu_lock);
-	kvm_release_pfn_clean(fault->pfn);
 	return r;
 }
 
@@ -4641,8 +4647,8 @@  static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu,
 	r = kvm_tdp_mmu_map(vcpu, fault);
 
 out_unlock:
+	kvm_mmu_finish_page_fault(vcpu, fault, r);
 	read_unlock(&vcpu->kvm->mmu_lock);
-	kvm_release_pfn_clean(fault->pfn);
 	return r;
 }
 #endif
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index e1c2f098d9d5..b6897916c76b 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -835,8 +835,8 @@  static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	r = FNAME(fetch)(vcpu, fault, &walker);
 
 out_unlock:
+	kvm_mmu_finish_page_fault(vcpu, fault, r);
 	write_unlock(&vcpu->kvm->mmu_lock);
-	kvm_release_pfn_clean(fault->pfn);
 	return r;
 }