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Message-ID: <3551d65c-2295-b6cd-b5b1-9264026cff61@intel.com>
Date:   Tue, 1 Aug 2023 14:12:35 +0300
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Subject: Re: [PATCH] scsi: ufs: ufs-pci: Add support for QEMU
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To:     jeuk20.kim@samsung.com
Cc:     "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        "avri.altman@wdc.com" <avri.altman@wdc.com>,
        "dlunev@chromium.org" <dlunev@chromium.org>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <48f05875-5255-70d2-0737-36fa95470037@intel.com>
 <20230801073750epcms2p121c08e452aaafdda301c5562f4ccff5b@epcms2p1>
 <CGME20230801073750epcms2p121c08e452aaafdda301c5562f4ccff5b@epcms2p4>
 <20230801092000epcms2p44c99d2c15bc6169e38693cb64cf946db@epcms2p4>
From:   Adrian Hunter <adrian.hunter@intel.com>
Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki,
 Business Identity Code: 0357606 - 4, Domiciled in Helsinki
In-Reply-To: <20230801092000epcms2p44c99d2c15bc6169e38693cb64cf946db@epcms2p4>
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On 1/08/23 12:20, Jeuk Kim wrote:
> On 1/08/23, Adrian Hunter wrote:
>> On 1/08/23 10:37, Jeuk Kim wrote:
>>> Add PCI ID to support QEMU ufs.
>>>
>>> The new qemu ufs device can be found at
>>> https://lore.kernel.org/qemu-devel/20230727155239.GA979354@fedora
>>
>> Please say something about why a UFS device is being virtualized
>> and what features it is expected to support.
> 
> Hi Adrian!
> 
> UFS device emulation feature has been newly added to QEMU recently.
> Currently, QEMU UFS supports basic io and query request features,
> and plans to add more features in the future.
> 
> With the addition of the QEMU ufs device emulation feature, 
> QEMU UFS decided to use the pci device id of 0x0013 in the REDHAT vendor id (0x1b36).
> 
> However, this information is not registered in the linux ufs driver, 
> so the current linux kernel does not recognize the QEMU UFS device. 
> Therefore, I want to register the QEMU ufs pci id through this patch.
> 
> Do I need to add the above content to the commit message?

I was really hoping for an explanation of "Why?" i.e.
why does anyone want a virtual UFS device?  Why not use
any existing virtual block device?

And yes, please add to the commit message

> 
> Thanks,
> Jeuk
> 
>>>
>>> Signed-off-by: Jeuk Kim <jeuk20.kim@samsung.com>
>>> ---
>>>   drivers/ufs/host/ufshcd-pci.c | 1 +
>>>   1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/ufs/host/ufshcd-pci.c b/drivers/ufs/host/ufshcd-pci.c
>>> index cf3987773051..29d322931427 100644
>>> --- a/drivers/ufs/host/ufshcd-pci.c
>>> +++ b/drivers/ufs/host/ufshcd-pci.c
>>> @@ -590,6 +590,7 @@ static const struct dev_pm_ops ufshcd_pci_pm_ops = {
>>>   };
>>>   
>>>   static const struct pci_device_id ufshcd_pci_tbl[] = {
>>> +        { PCI_VENDOR_ID_REDHAT, 0x0013, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
>>>           { PCI_VENDOR_ID_SAMSUNG, 0xC00C, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
>>>           { PCI_VDEVICE(INTEL, 0x9DFA), (kernel_ulong_t)&ufs_intel_cnl_hba_vops },
>>>           { PCI_VDEVICE(INTEL, 0x4B41), (kernel_ulong_t)&ufs_intel_ehl_hba_vops },