KVM: Synchronize guest physical memory map to host virtual memory map

[linux-2.6] / arch / x86 / kvm / paging_tmpl.h

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 4d918220baebf128f3db1d825f2b23895f53c933..f72ac1fa35f0bfe07b74b43f2275c28402518c9e 100644 (file)
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -263,6 +263,8 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
        pfn = vcpu->arch.update_pte.pfn;
        if (is_error_pfn(pfn))
                return;
+       if (mmu_notifier_retry(vcpu, vcpu->arch.update_pte.mmu_seq))
+               return;
        kvm_get_pfn(pfn);
        mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
                     gpte & PT_DIRTY_MASK, NULL, largepage, gpte_to_gfn(gpte),
@@ -380,6 +382,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        int r;
        pfn_t pfn;
        int largepage = 0;
+       unsigned long mmu_seq;
 
        pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
        kvm_mmu_audit(vcpu, "pre page fault");
@@ -413,6 +416,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                        largepage = 1;
                }
        }
+       mmu_seq = vcpu->kvm->mmu_notifier_seq;
+       /* implicit mb(), we'll read before PT lock is unlocked */
        pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
        up_read(&current->mm->mmap_sem);
 
@@ -424,6 +429,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        }
 
        spin_lock(&vcpu->kvm->mmu_lock);
+       if (mmu_notifier_retry(vcpu, mmu_seq))
+               goto out_unlock;
        kvm_mmu_free_some_pages(vcpu);
        shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
                                  largepage, &write_pt, pfn);
@@ -439,6 +446,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        spin_unlock(&vcpu->kvm->mmu_lock);
 
        return write_pt;
+
+out_unlock:
+       spin_unlock(&vcpu->kvm->mmu_lock);
+       kvm_release_pfn_clean(pfn);
+       return 0;
 }
 
 static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)