KVM: MMU: abstract some functions to handle fault pfn

Introduce handle_abnormal_pfn to handle fault pfn on page fault path,
introduce mmu_invalid_pfn to handle fault pfn on prefetch path

It is the preparing work for mmio page fault support

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 35 insertions, 12 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 96a7ed4e6837..1d4a2d9cc718 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2221,18 +2221,15 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *
 	send_sig_info(SIGBUS, &info, tsk);
 }
 
-static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gva_t gva,
-			       unsigned access, gfn_t gfn, pfn_t pfn)
+static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, pfn_t pfn)
 {
 	kvm_release_pfn_clean(pfn);
 	if (is_hwpoison_pfn(pfn)) {
 		kvm_send_hwpoison_signal(gfn_to_hva(vcpu->kvm, gfn), current);
 		return 0;
-	} else if (is_fault_pfn(pfn))
-		return -EFAULT;
+	}
 
-	vcpu_cache_mmio_info(vcpu, gva, gfn, access);
-	return 1;
+	return -EFAULT;
 }
 
 static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
@@ -2277,6 +2274,33 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
 	}
 }
 
+static bool mmu_invalid_pfn(pfn_t pfn)
+{
+	return unlikely(is_invalid_pfn(pfn) || is_noslot_pfn(pfn));
+}
+
+static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
+				pfn_t pfn, unsigned access, int *ret_val)
+{
+	bool ret = true;
+
+	/* The pfn is invalid, report the error! */
+	if (unlikely(is_invalid_pfn(pfn))) {
+		*ret_val = kvm_handle_bad_page(vcpu, gfn, pfn);
+		goto exit;
+	}
+
+	if (unlikely(is_noslot_pfn(pfn))) {
+		vcpu_cache_mmio_info(vcpu, gva, gfn, access);
+		*ret_val = 1;
+		goto exit;
+	}
+
+	ret = false;
+exit:
+	return ret;
+}
+
 static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 			 gva_t gva, pfn_t *pfn, bool write, bool *writable);
 
@@ -2311,9 +2335,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn,
 	if (try_async_pf(vcpu, prefault, gfn, v, &pfn, write, &map_writable))
 		return 0;
 
-	/* mmio */
-	if (is_error_pfn(pfn))
-		return kvm_handle_bad_page(vcpu, v, ACC_ALL, gfn, pfn);
+	if (handle_abnormal_pfn(vcpu, v, gfn, pfn, ACC_ALL, &r))
+		return r;
 
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (mmu_notifier_retry(vcpu, mmu_seq))
@@ -2685,9 +2708,9 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
 	if (try_async_pf(vcpu, prefault, gfn, gpa, &pfn, write, &map_writable))
 		return 0;
 
-	/* mmio */
-	if (is_error_pfn(pfn))
-		return kvm_handle_bad_page(vcpu, 0, 0, gfn, pfn);
+	if (handle_abnormal_pfn(vcpu, 0, gfn, pfn, ACC_ALL, &r))
+		return r;
+
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (mmu_notifier_retry(vcpu, mmu_seq))
 		goto out_unlock;