[PATCH v2 10/19] KVM: Use follow_pfnmap API

[Peter Xu <peterx@redhat.com>]

Use the new pfnmap API to allow huge MMIO mappings for VMs.  The rest work
is done perfectly on the other side (host_pfn_mapping_level()).

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 virt/kvm/kvm_main.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cb2b78e92910..f416d5e3f9c0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2860,13 +2860,11 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
 			       unsigned long addr, bool write_fault,
 			       bool *writable, kvm_pfn_t *p_pfn)
 {
+	struct follow_pfnmap_args args = { .vma = vma, .address = addr };
 	kvm_pfn_t pfn;
-	pte_t *ptep;
-	pte_t pte;
-	spinlock_t *ptl;
 	int r;
 
-	r = follow_pte(vma, addr, &ptep, &ptl);
+	r = follow_pfnmap_start(&args);
 	if (r) {
 		/*
 		 * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
@@ -2881,21 +2879,19 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
 		if (r)
 			return r;
 
-		r = follow_pte(vma, addr, &ptep, &ptl);
+		r = follow_pfnmap_start(&args);
 		if (r)
 			return r;
 	}
 
-	pte = ptep_get(ptep);
-
-	if (write_fault && !pte_write(pte)) {
+	if (write_fault && !args.writable) {
 		pfn = KVM_PFN_ERR_RO_FAULT;
 		goto out;
 	}
 
 	if (writable)
-		*writable = pte_write(pte);
-	pfn = pte_pfn(pte);
+		*writable = args.writable;
+	pfn = args.pfn;
 
 	/*
 	 * Get a reference here because callers of *hva_to_pfn* and
@@ -2916,9 +2912,8 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
 	 */
 	if (!kvm_try_get_pfn(pfn))
 		r = -EFAULT;
-
 out:
-	pte_unmap_unlock(ptep, ptl);
+	follow_pfnmap_end(&args);
 	*p_pfn = pfn;
 
 	return r;
-- 
2.45.0