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KVM: x86: Fix warning due to implicit truncation on 32-bit KVM

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Explicitly cast the integer literal to an unsigned long when stuffing a
non-canonical value into the host virtual address during private memslot
deletion.  The explicit cast fixes a warning that gets promoted to an
error when running with KVM's newfangled -Werror setting.

  arch/x86/kvm/x86.c:9739:9: error: large integer implicitly truncated
  to unsigned type [-Werror=overflow]

Fixes: a3e967c0b87d3 ("KVM: Terminate memslot walks via used_slots"
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2020-03-04 16:24:22 -08:00 committed by Paolo Bonzini
parent 96d4701049
commit abbed4fa94
1 changed files with 6 additions and 2 deletions
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8
arch/x86/kvm/x86.c
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@ -9735,8 +9735,12 @@ int __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
if (!slot || !slot->npages)
return 0;
/* Stuff a non-canonical value to catch use-after-delete. */
hva = 0xdeadull << 48;
/*
* Stuff a non-canonical value to catch use-after-delete. This
* ends up being 0 on 32-bit KVM, but there's no better
* alternative.
*/
hva = (unsigned long)(0xdeadull << 48);
old_npages = slot->npages;
}