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Date: Tue, 7 Jan 2020 16:18:59 -0800 From: Sean Christopherson <sean.j.christopherson@...el.com> To: Paolo Bonzini <pbonzini@...hat.com> Cc: Sean Christopherson <sean.j.christopherson@...el.com>, Vitaly Kuznetsov <vkuznets@...hat.com>, Wanpeng Li <wanpengli@...cent.com>, Jim Mattson <jmattson@...gle.com>, Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org, linux-kernel@...r.kernel.org Subject: [PATCH] KVM: x86/mmu: Fix a benign Bitwise vs. Logical OR mixup Use a Logical OR in __is_rsvd_bits_set() to combine the two reserved bit checks, which are obviously intended to be logical statements. Switching to a Logical OR is functionally a nop, but allows the compiler to better optimize the checks. Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com> --- arch/x86/kvm/mmu/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 7269130ea5e2..72e845709027 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3970,7 +3970,7 @@ __is_rsvd_bits_set(struct rsvd_bits_validate *rsvd_check, u64 pte, int level) { int bit7 = (pte >> 7) & 1, low6 = pte & 0x3f; - return (pte & rsvd_check->rsvd_bits_mask[bit7][level-1]) | + return (pte & rsvd_check->rsvd_bits_mask[bit7][level-1]) || ((rsvd_check->bad_mt_xwr & (1ull << low6)) != 0); } -- 2.24.1
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