KVM: Add kvm_read_guest_atomic()

[deliverable/linux.git] / arch / x86 / kvm / paging_tmpl.h

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 7f83f5557d5ee08118e51f3d43d9bc2116d141ce..136a65d72b0afd18c406129fbe692d0e9c1cfb3a 100644 (file)
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -316,10 +316,12 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                                               metaphysical, access,
                                               shadow_ent, &new_page);
                if (new_page && !metaphysical) {
+                       int r;
                        pt_element_t curr_pte;
-                       kvm_read_guest(vcpu->kvm, walker->pte_gpa[level - 2],
-                                      &curr_pte, sizeof(curr_pte));
-                       if (curr_pte != walker->ptes[level - 2])
+                       r = kvm_read_guest_atomic(vcpu->kvm,
+                                                 walker->pte_gpa[level - 2],
+                                                 &curr_pte, sizeof(curr_pte));
+                       if (r || curr_pte != walker->ptes[level - 2])
                                return NULL;
                }
                shadow_addr = __pa(shadow_page->spt);
@@ -429,9 +431,8 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
 static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
                                 struct kvm_mmu_page *sp)
 {
-       int i, offset = 0;
-       pt_element_t *gpt;
-       struct page *page;
+       int i, offset = 0, r = 0;
+       pt_element_t pt;
 
        if (sp->role.metaphysical
            || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) {
@@ -441,15 +442,18 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
 
        if (PTTYPE == 32)
                offset = sp->role.quadrant << PT64_LEVEL_BITS;
-       page = gfn_to_page(vcpu->kvm, sp->gfn);
-       gpt = kmap_atomic(page, KM_USER0);
-       for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
-               if (is_present_pte(gpt[offset + i]))
+
+       for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
+               gpa_t pte_gpa = gfn_to_gpa(sp->gfn);
+               pte_gpa += (i+offset) * sizeof(pt_element_t);
+
+               r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &pt,
+                                         sizeof(pt_element_t));
+               if (r || is_present_pte(pt))
                        sp->spt[i] = shadow_trap_nonpresent_pte;
                else
                        sp->spt[i] = shadow_notrap_nonpresent_pte;
-       kunmap_atomic(gpt, KM_USER0);
-       kvm_release_page_clean(page);
+       }
 }
 
 #undef pt_element_t