[16/29] KVM: MMU: Introduce kvm_read_nested_guest_page()

Commit Message

Joerg Roedel Sept. 10, 2010, 3:30 p.m. UTC

None

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 34bc840..540255d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -392,6 +392,13 @@  int kvm_read_guest_page_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 }
 EXPORT_SYMBOL_GPL(kvm_read_guest_page_mmu);
 
+int kvm_read_nested_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
+			       void *data, int offset, int len, u32 access)
+{
+	return kvm_read_guest_page_mmu(vcpu, vcpu->arch.walk_mmu, gfn,
+				       data, offset, len, access);
+}
+
 /*
  * Load the pae pdptrs.  Return true is they are all valid.
  */
@@ -403,8 +410,9 @@  int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
 	int ret;
 	u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
 
-	ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte,
-				  offset * sizeof(u64), sizeof(pdpte));
+	ret = kvm_read_nested_guest_page(vcpu, pdpt_gfn, pdpte,
+					 offset * sizeof(u64), sizeof(pdpte),
+					 PFERR_USER_MASK|PFERR_WRITE_MASK);
 	if (ret < 0) {
 		ret = 0;
 		goto out;
@@ -433,6 +441,8 @@  static bool pdptrs_changed(struct kvm_vcpu *vcpu)
 {
 	u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
 	bool changed = true;
+	int offset;
+	gfn_t gfn;
 	int r;
 
 	if (is_long_mode(vcpu) || !is_pae(vcpu))
@@ -442,7 +452,10 @@  static bool pdptrs_changed(struct kvm_vcpu *vcpu)
 		      (unsigned long *)&vcpu->arch.regs_avail))
 		return true;
 
-	r = kvm_read_guest(vcpu->kvm, vcpu->arch.cr3 & ~31u, pdpte, sizeof(pdpte));
+	gfn = (vcpu->arch.cr3 & ~31u) >> PAGE_SHIFT;
+	offset = (vcpu->arch.cr3 & ~31u) & (PAGE_SIZE - 1);
+	r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
+				       PFERR_USER_MASK | PFERR_WRITE_MASK);
 	if (r < 0)
 		goto out;
 	changed = memcmp(pdpte, vcpu->arch.pdptrs, sizeof(pdpte)) != 0;