Commit abbed4fa authored Mar 04, 2020 by Sean Christopherson Committed by Paolo Bonzini Mar 16, 2020

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

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>

parent 96d47010

arch/x86/kvm/x86.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

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