KVM: MMU: Extend kvm_mmu_page->slot_bitmap size

Otherwise set_bit() for private memory slot(above KVM_MEMORY_SLOTS) would
corrupted memory in 32bit host.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 93040b5..59c3ae1 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -192,9 +192,11 @@ struct kvm_mmu_page {
        u64 *spt;
        /* hold the gfn of each spte inside spt */
        gfn_t *gfns;
-       unsigned long slot_bitmap; /* One bit set per slot which has memory
-                                   * in this shadow page.
-                                   */
+       /*
+        * One bit set per slot which has memory
+        * in this shadow page.
+        */
+       DECLARE_BITMAP(slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
        int multimapped;         /* More than one parent_pte? */
        int root_count;          /* Currently serving as active root */
        bool unsync;

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 09d05f5..8687758 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -789,7 +789,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
        set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
        list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
        ASSERT(is_empty_shadow_page(sp->spt));
-       sp->slot_bitmap = 0;
+       bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
        sp->multimapped = 0;
        sp->parent_pte = parent_pte;
        --vcpu->kvm->arch.n_free_mmu_pages;
@@ -1364,7 +1364,7 @@ static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
        int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
        struct kvm_mmu_page *sp = page_header(__pa(pte));
 
-       __set_bit(slot, &sp->slot_bitmap);
+       __set_bit(slot, sp->slot_bitmap);
 }
 
 static void mmu_convert_notrap(struct kvm_mmu_page *sp)
@@ -2564,7 +2564,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
                int i;
                u64 *pt;
 
-               if (!test_bit(slot, &sp->slot_bitmap))
+               if (!test_bit(slot, sp->slot_bitmap))
                        continue;
 
                pt = sp->spt;