KVM: switch to get_user_pages_fast

[firefly-linux-kernel-4.4.55.git] / arch / x86 / kvm / paging_tmpl.h

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index b671f61be41e61a9aa277a549907874cb5b235a5..6dd08e096e2492cb420e7f50afc7b11deb1db4d3 100644 (file)
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -102,14 +102,10 @@ static bool FNAME(cmpxchg_gpte)(struct kvm *kvm,
        pt_element_t *table;
        struct page *page;
 
-       down_read(&current->mm->mmap_sem);
        page = gfn_to_page(kvm, table_gfn);
-       up_read(&current->mm->mmap_sem);
 
        table = kmap_atomic(page, KM_USER0);
-
        ret = CMPXCHG(&table[index], orig_pte, new_pte);
-
        kunmap_atomic(table, KM_USER0);
 
        kvm_release_page_dirty(page);
@@ -418,7 +414,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                return 0;
        }
 
-       down_read(&current->mm->mmap_sem);
        if (walker.level == PT_DIRECTORY_LEVEL) {
                gfn_t large_gfn;
                large_gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE-1);
@@ -428,9 +423,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                }
        }
        mmu_seq = vcpu->kvm->mmu_notifier_seq;
-       /* implicit mb(), we'll read before PT lock is unlocked */
+       smp_rmb();
        pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
-       up_read(&current->mm->mmap_sem);
 
        /* mmio */
        if (is_error_pfn(pfn)) {