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Subject: Re: [PATCH] iommu/vt-d: Fix PASID cache flush
To:     Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc:     iommu@lists.linux-foundation.org,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Raj Ashok <ashok.raj@intel.com>
References: <1585610725-78316-1-git-send-email-jacob.jun.pan@linux.intel.com>
 <53be1d27-6348-56db-7eac-6734f92f123d@redhat.com>
 <20200331090843.59961e03@jacob-builder>
From:   Auger Eric <eric.auger@redhat.com>
Message-ID: <2e9fc0f5-6181-0a10-db59-67e0ffca14cd@redhat.com>
Date:   Tue, 31 Mar 2020 18:19:25 +0200
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Hi Jacob,

On 3/31/20 6:08 PM, Jacob Pan wrote:
> Actually, this is not a bug. The current code has:
> #define QI_PC_PASID_SEL             (QI_PC_TYPE | QI_PC_GRAN(1))
> 
> Which already has the type and shift.
> 
> In my vSVA series, I redefined granu such that I can use them in the 2D
> table lookup.
> 
> -#define QI_PC_ALL_PASIDS       (QI_PC_TYPE | QI_PC_GRAN(0))        
> -#define QI_PC_PASID_SEL                (QI_PC_TYPE | QI_PC_GRAN(1))
> +/* PASID cache invalidation granu */                               
> +#define QI_PC_ALL_PASIDS       0                                   
> +#define QI_PC_PASID_SEL                1                           
> 
> Please ignore this, sorry about the confusion.
OK I missed that as well, sorry. So that's not a fix but the code will
become more readable/consistent in your vSVA series.

Thanks

Eric
> 
> On Tue, 31 Mar 2020 11:28:17 +0200
> Auger Eric <eric.auger@redhat.com> wrote:
> 
>> Hi Jacob,
>>
>> On 3/31/20 1:25 AM, Jacob Pan wrote:
>>> PASID cache type and shift of granularity bits are missing in
>>> the current code.
>>>
>>> Fixes: 6f7db75e1c46 ("iommu/vt-d: Add second level page table
>>> interface")
>>>
>>> Cc: Eric Auger <eric.auger@redhat.com>
>>> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>  
>> Reviewed-by: Eric Auger <eric.auger@redhat.com>
>>
>> Thanks
>>
>> Eric
>>
>>> ---
>>>  drivers/iommu/intel-pasid.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/iommu/intel-pasid.c
>>> b/drivers/iommu/intel-pasid.c index 22b30f10b396..57d05b0fbafc
>>> 100644 --- a/drivers/iommu/intel-pasid.c
>>> +++ b/drivers/iommu/intel-pasid.c
>>> @@ -365,7 +365,8 @@ pasid_cache_invalidation_with_pasid(struct
>>> intel_iommu *iommu, {
>>>  	struct qi_desc desc;
>>>  
>>> -	desc.qw0 = QI_PC_DID(did) | QI_PC_PASID_SEL |
>>> QI_PC_PASID(pasid);
>>> +	desc.qw0 = QI_PC_DID(did) | QI_PC_GRAN(QI_PC_PASID_SEL) |
>>> +		   QI_PC_PASID(pasid) | QI_PC_TYPE;
>>>  	desc.qw1 = 0;
>>>  	desc.qw2 = 0;
>>>  	desc.qw3 = 0;
>>>   
>>
> 
> [Jacob Pan]
>