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From: Moritz Fischer <mdf@kernel.org>
To: Yonghyun Hwang <yonghyun@google.com>
Cc: linux-kernel@vger.kernel.org,
	Havard Skinnemoen <hskinnemoen@google.com>,
	iommu@lists.linux-foundation.org,
	Deepa Dinamani <deepadinamani@google.com>,
	Moritz Fischer <mdf@kernel.org>,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH v2] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page
Date: Sat, 22 Feb 2020 11:02:28 -0800	[thread overview]
Message-ID: <20200222190228.GA7728@epycbox.lan> (raw)
In-Reply-To: <20200220194431.169629-1-yonghyun@google.com>

On Thu, Feb 20, 2020 at 11:44:31AM -0800, Yonghyun Hwang wrote:
> intel_iommu_iova_to_phys() has a bug when it translates an IOVA for a huge
> page onto its corresponding physical address. This commit fixes the bug by
> accomodating the level of page entry for the IOVA and adds IOVA's lower
> address to the physical address.
> 
> Signed-off-by: Yonghyun Hwang <yonghyun@google.com>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
> ---
> 
> Changes from v1:
> - level cannot be 0. So, the condition, "if (level > 1)", is removed, which results in a simple code.
> - a macro, BIT_MASK, is used to have a bit mask
> 
> ---
>  drivers/iommu/intel-iommu.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 932267f49f9a..4fd5c6287b6d 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -5554,7 +5554,9 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
>  
>  	pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
>  	if (pte)
> -		phys = dma_pte_addr(pte);
> +		phys = dma_pte_addr(pte) +
> +			(iova & (BIT_MASK(level_to_offset_bits(level) +
> +						VTD_PAGE_SHIFT) - 1));
>  
>  	return phys;
>  }
> -- 
> 2.25.0.265.gbab2e86ba0-goog
> 
_______________________________________________
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iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Moritz Fischer <mdf@kernel.org>
To: Yonghyun Hwang <yonghyun@google.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
	Lu Baolu <baolu.lu@linux.intel.com>,
	Joerg Roedel <joro@8bytes.org>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Havard Skinnemoen <hskinnemoen@google.com>,
	Deepa Dinamani <deepadinamani@google.com>,
	Moritz Fischer <mdf@kernel.org>
Subject: Re: [PATCH v2] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page
Date: Sat, 22 Feb 2020 11:02:28 -0800	[thread overview]
Message-ID: <20200222190228.GA7728@epycbox.lan> (raw)
In-Reply-To: <20200220194431.169629-1-yonghyun@google.com>

On Thu, Feb 20, 2020 at 11:44:31AM -0800, Yonghyun Hwang wrote:
> intel_iommu_iova_to_phys() has a bug when it translates an IOVA for a huge
> page onto its corresponding physical address. This commit fixes the bug by
> accomodating the level of page entry for the IOVA and adds IOVA's lower
> address to the physical address.
> 
> Signed-off-by: Yonghyun Hwang <yonghyun@google.com>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
> ---
> 
> Changes from v1:
> - level cannot be 0. So, the condition, "if (level > 1)", is removed, which results in a simple code.
> - a macro, BIT_MASK, is used to have a bit mask
> 
> ---
>  drivers/iommu/intel-iommu.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 932267f49f9a..4fd5c6287b6d 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -5554,7 +5554,9 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
>  
>  	pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
>  	if (pte)
> -		phys = dma_pte_addr(pte);
> +		phys = dma_pte_addr(pte) +
> +			(iova & (BIT_MASK(level_to_offset_bits(level) +
> +						VTD_PAGE_SHIFT) - 1));
>  
>  	return phys;
>  }
> -- 
> 2.25.0.265.gbab2e86ba0-goog
> 

  parent reply	other threads:[~2020-02-22 19:02 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-20 19:44 [PATCH v2] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page Yonghyun Hwang via iommu
2020-02-20 19:44 ` Yonghyun Hwang
2020-02-20 19:50 ` Moritz Fischer
2020-02-20 19:50   ` Moritz Fischer
2020-02-22 13:05 ` Lu Baolu
2020-02-22 13:05   ` Lu Baolu
2020-02-22 13:08   ` Lu Baolu
2020-02-22 13:08     ` Lu Baolu
2020-02-24 14:05   ` Lu Baolu
2020-02-24 14:05     ` Lu Baolu
2020-02-22 19:02 ` Moritz Fischer [this message]
2020-02-22 19:02   ` Moritz Fischer
2020-02-25  5:53 ` Lu Baolu
2020-02-25  5:53   ` Lu Baolu

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