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From:   Jim Mattson <jmattson@google.com>
Date:   Tue, 15 May 2018 14:55:17 -0700
Message-ID: <CALMp9eRLZO4Ou3W=1hJ93OyBp+-ykP4nefOSXeyZn-XePFBg+A@mail.gmail.com>
Subject: Re: [PATCH 1/3] KVM: VMX: Introduce per-VM I/O permission bitmaps
To:     Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc:     Wanpeng Li <kernellwp@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        kvm list <kvm@vger.kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Tim Shearer <tshearer@advaoptical.com>,
        Liran Alon <liran.alon@oracle.com>
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Since these pages are typically not used, can we allocate them conditionally?

On Fri, May 11, 2018 at 8:39 AM, Konrad Rzeszutek Wilk
<konrad.wilk@oracle.com> wrote:
>>       /*
>> -      * A vmexit (to either L1 hypervisor or L0 userspace) is always needed
>> -      * for I/O port accesses.
>> +      * Merging of IO bitmap not currently supported.
>
> s/not/is not/
>
> And with that
>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>
> Thank you!
>> +      * Rather, exit every time.
>>        */
>>       exec_control &= ~CPU_BASED_USE_IO_BITMAPS;
>>       exec_control |= CPU_BASED_UNCOND_IO_EXITING;
>> --
>> 2.7.4
>>