kvm: fix previous commit for 32-bit builds

commit 4422829e8053068e0225e4d0ef42dc41ea7c9ef5 upstream.

array_index_nospec does not work for uint64_t on 32-bit builds.
However, the size of a memory slot must be less than 20 bits wide
on those system, since the memory slot must fit in the user
address space.  So just store it in an unsigned long.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index eb758bbdb4f6562b9506e4023bf4bddf73cc84ff..8dd4ebb58e9733bdbd6f3af8e8986b70f8ee06c2 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1023,8 +1023,8 @@ __gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
         * table walks, do not let the processor speculate loads outside
         * the guest's registered memslots.
         */
-       unsigned long offset = array_index_nospec(gfn - slot->base_gfn,
-                                                 slot->npages);
+       unsigned long offset = gfn - slot->base_gfn;
+       offset = array_index_nospec(offset, slot->npages);
        return slot->userspace_addr + offset * PAGE_SIZE;
 }