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Subject: Re: [PATCH v2 2/3] KVM: VMX: Replace MSR_IA32_RTIT_OUTPUT_BASE_MASK
 with helper function
To:     Sean Christopherson <sean.j.christopherson@intel.com>
Cc:     Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20200923163629.20168-1-sean.j.christopherson@intel.com>
 <20200923163629.20168-3-sean.j.christopherson@intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <0a215e25-798d-3f17-0fcb-885806f2351b@redhat.com>
Date:   Wed, 23 Sep 2020 19:07:22 +0200
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On 23/09/20 18:36, Sean Christopherson wrote:
> +static inline bool pt_output_base_valid(struct kvm_vcpu *vcpu, u64 base)
> +{
> +	/* The base must be 128-byte aligned and a legal physical address. */
> +	return !(base & (~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f));
> +}

The fact that you deemed a comment necessary says something already. :)
What about:

        return !kvm_mmu_is_illegal_gpa(vcpu, base) && !(base & 0x7f);

(where this new usage makes it obvious that mmu should have been vcpu).

Paolo