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To:     Chenyi Qiang <chenyi.qiang@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        Xiaoyao Li <xiaoyao.li@intel.com>
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210202090433.13441-1-chenyi.qiang@intel.com>
 <20210202090433.13441-2-chenyi.qiang@intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v2 1/3] KVM: X86: Rename DR6_INIT to DR6_ACTIVE_LOW
Message-ID: <3db069ba-b4e0-1288-ec79-66ac44938682@redhat.com>
Date:   Tue, 2 Feb 2021 15:49:56 +0100
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On 02/02/21 10:04, Chenyi Qiang wrote:
> 
>  #define DR6_FIXED_1	0xfffe0ff0
> -#define DR6_INIT	0xffff0ff0
> +/*
> + * DR6_ACTIVE_LOW is actual the result of DR6_FIXED_1 | ACTIVE_LOW_BITS.
> + * We can regard all the current FIXED_1 bits as active_low bits even
> + * though in no case they will be turned into 0. But if they are defined
> + * in the future, it will require no code change.
> + * At the same time, it can be served as the init/reset value for DR6.
> + */
> +#define DR6_ACTIVE_LOW	0xffff0ff0
>  #define DR6_VOLATILE	0x0001e00f
>  

Committed with some changes in the wording of the comment.

Also, DR6_FIXED_1 is (DR6_ACTIVE_LOW & ~DR6_VOLATILE).

Paolo