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References: <20230329163107.GA3061927@bhelgaas> <0603c75d-82d3-01d5-ffe7-b648c1f02f0e@linux.intel.com>
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From:   Xinghui Li <korantwork@gmail.com>
Date:   Sun, 2 Apr 2023 22:34:00 +0800
Message-ID: <CAEm4hYXwGuuZiKb9psXPyau+zKq-w=VboJEuYbS0FbY-iT-EmA@mail.gmail.com>
Subject: Re: [PATCH v4] PCI: vmd: Add the module param to adjust MSI mode
To:     "Patel, Nirmal" <nirmal.patel@linux.intel.com>
Cc:     Bjorn Helgaas <helgaas@kernel.org>, kbusch@kernel.org,
        jonathan.derrick@linux.dev, lpieralisi@kernel.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        Xinghui Li <korantli@tencent.com>
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On Thu, Mar 30, 2023 at 2:49=E2=80=AFPM Patel, Nirmal
<nirmal.patel@linux.intel.com> wrote:
>
> How about adding a boolean flag by comparing user input for module
> parameter msi_remap? and add the flag at
>
>     - if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) || msi_flag
>         || offset[0] || offset[1])
>
> Correct if I am wrong, but in this way we can cover all the cases.
> If user adds msi_remap=3Don, msi_flag=3Dtrue and enables remapping.
> If user adds msi_remap=3Doff, msi_flag=3Dfalse and disables remapping.
> If user doesn't add anything, msi_flag=3Dfalse and decision will be
> made same as current implementation. This will cover guest OS case
> as well.
>
Sorry, I don't quite get your point. How is msi_flag assigned?
Do you mean when msi_remap=3Dno, the msi_flag is assigned as true?
And msi_remap=3Doff, the msi_flag is assigned as false?

Thanks~