[Part2,v5,29/45] KVM: x86/mmu: Move 'pfn' variable to caller of direct_page_fault()

Commit Message

Brijesh Singh Aug. 20, 2021, 3:59 p.m. UTC

From: Sean Christopherson <[e-mail]>

When adding pages prior to boot, TDX will need the resulting host pfn so
that it can be passed to TDADDPAGE (TDX-SEAM always works with physical
addresses as it has its own page tables).  Start plumbing pfn back up
the page fault stack.

Signed-off-by: Sean Christopherson <[e-mail]>
Signed-off-by: Isaku Yamahata <[e-mail]>
Signed-off-by: Brijesh Singh <[e-mail]>
---
 arch/x86/kvm/mmu/mmu.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index f9aaf6e1e51e..5cbcbedcaaa6 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3818,7 +3818,8 @@  static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 }
 
 static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
-			     bool prefault, int max_level, bool is_tdp)
+			     bool prefault, int max_level, bool is_tdp,
+			     kvm_pfn_t *pfn)
 {
 	bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
 	bool write = error_code & PFERR_WRITE_MASK;
@@ -3826,7 +3827,6 @@  static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 
 	gfn_t gfn = gpa >> PAGE_SHIFT;
 	unsigned long mmu_seq;
-	kvm_pfn_t pfn;
 	hva_t hva;
 	int r;
 
@@ -3846,11 +3846,11 @@  static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
 	smp_rmb();
 
-	if (try_async_pf(vcpu, prefault, gfn, gpa, &pfn, &hva,
+	if (try_async_pf(vcpu, prefault, gfn, gpa, pfn, &hva,
 			 write, &map_writable))
 		return RET_PF_RETRY;
 
-	if (handle_abnormal_pfn(vcpu, is_tdp ? 0 : gpa, gfn, pfn, ACC_ALL, &r))
+	if (handle_abnormal_pfn(vcpu, is_tdp ? 0 : gpa, gfn, *pfn, ACC_ALL, &r))
 		return r;
 
 	r = RET_PF_RETRY;
@@ -3860,7 +3860,8 @@  static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 	else
 		write_lock(&vcpu->kvm->mmu_lock);
 
-	if (!is_noslot_pfn(pfn) && mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, hva))
+	if (!is_noslot_pfn(*pfn) &&
+	    mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, hva))
 		goto out_unlock;
 	r = make_mmu_pages_available(vcpu);
 	if (r)
@@ -3868,9 +3869,9 @@  static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 
 	if (is_tdp_mmu_fault)
 		r = kvm_tdp_mmu_map(vcpu, gpa, error_code, map_writable, max_level,
-				    pfn, prefault);
+				    *pfn, prefault);
 	else
-		r = __direct_map(vcpu, gpa, error_code, map_writable, max_level, pfn,
+		r = __direct_map(vcpu, gpa, error_code, map_writable, max_level, *pfn,
 				 prefault, is_tdp);
 
 out_unlock:
@@ -3878,18 +3879,20 @@  static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 		read_unlock(&vcpu->kvm->mmu_lock);
 	else
 		write_unlock(&vcpu->kvm->mmu_lock);
-	kvm_release_pfn_clean(pfn);
+	kvm_release_pfn_clean(*pfn);
 	return r;
 }
 
 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa,
 				u32 error_code, bool prefault)
 {
+	kvm_pfn_t pfn;
+
 	pgprintk("%s: gva %lx error %x\n", __func__, gpa, error_code);
 
 	/* This path builds a PAE pagetable, we can map 2mb pages at maximum. */
 	return direct_page_fault(vcpu, gpa & PAGE_MASK, error_code, prefault,
-				 PG_LEVEL_2M, false);
+				 PG_LEVEL_2M, false, &pfn);
 }
 
 int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
@@ -3928,6 +3931,7 @@  EXPORT_SYMBOL_GPL(kvm_handle_page_fault);
 int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 		       bool prefault)
 {
+	kvm_pfn_t pfn;
 	int max_level;
 
 	for (max_level = KVM_MAX_HUGEPAGE_LEVEL;
@@ -3941,7 +3945,7 @@  int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 	}
 
 	return direct_page_fault(vcpu, gpa, error_code, prefault,
-				 max_level, true);
+				 max_level, true, &pfn);
 }
 
 static void nonpaging_init_context(struct kvm_mmu *context)