All of lore.kernel.org
 help / color / mirror / Atom feed
From: Lu Baolu <baolu.lu@linux.intel.com>
To: Yonghyun Hwang <yonghyun@google.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>
Cc: baolu.lu@linux.intel.com, 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: Tue, 25 Feb 2020 13:53:07 +0800	[thread overview]
Message-ID: <0f38ea21-2129-22ec-3d35-03723054127e@linux.intel.com> (raw)
In-Reply-To: <20200220194431.169629-1-yonghyun@google.com>

Hi,

On 2020/2/21 3:44, 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>
> ---
> 
> 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)

Need to check whether the pte is present here. Otherwise, the returned
level makes no sense.

Increased change looks like:

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 61c7ef2f33b4..33593fea0250 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5700,7 +5700,7 @@ static phys_addr_t intel_iommu_iova_to_phys(struct 
iommu_domain *domain,
         u64 phys = 0;

         pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
-       if (pte)
+       if (pte && dma_pte_present(pte))
                 phys = dma_pte_addr(pte) +
                         (iova & (BIT_MASK(level_to_offset_bits(level) +
                                                 VTD_PAGE_SHIFT) - 1));

> -		phys = dma_pte_addr(pte);
> +		phys = dma_pte_addr(pte) +
> +			(iova & (BIT_MASK(level_to_offset_bits(level) +
> +						VTD_PAGE_SHIFT) - 1));
>   
>   	return phys;
>   }
> 

Best regards,
baolu

WARNING: multiple messages have this Message-ID (diff)
From: Lu Baolu <baolu.lu@linux.intel.com>
To: Yonghyun Hwang <yonghyun@google.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>
Cc: Havard Skinnemoen <hskinnemoen@google.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	Moritz Fischer <mdf@kernel.org>,
	Deepa Dinamani <deepadinamani@google.com>
Subject: Re: [PATCH v2] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page
Date: Tue, 25 Feb 2020 13:53:07 +0800	[thread overview]
Message-ID: <0f38ea21-2129-22ec-3d35-03723054127e@linux.intel.com> (raw)
In-Reply-To: <20200220194431.169629-1-yonghyun@google.com>

Hi,

On 2020/2/21 3:44, 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>
> ---
> 
> 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)

Need to check whether the pte is present here. Otherwise, the returned
level makes no sense.

Increased change looks like:

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 61c7ef2f33b4..33593fea0250 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5700,7 +5700,7 @@ static phys_addr_t intel_iommu_iova_to_phys(struct 
iommu_domain *domain,
         u64 phys = 0;

         pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
-       if (pte)
+       if (pte && dma_pte_present(pte))
                 phys = dma_pte_addr(pte) +
                         (iova & (BIT_MASK(level_to_offset_bits(level) +
                                                 VTD_PAGE_SHIFT) - 1));

> -		phys = dma_pte_addr(pte);
> +		phys = dma_pte_addr(pte) +
> +			(iova & (BIT_MASK(level_to_offset_bits(level) +
> +						VTD_PAGE_SHIFT) - 1));
>   
>   	return phys;
>   }
> 

Best regards,
baolu
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  parent reply	other threads:[~2020-02-25  5:53 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
2020-02-20 19:44 ` Yonghyun Hwang via iommu
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
2020-02-22 19:02   ` Moritz Fischer
2020-02-25  5:53 ` Lu Baolu [this message]
2020-02-25  5:53   ` Lu Baolu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=0f38ea21-2129-22ec-3d35-03723054127e@linux.intel.com \
    --to=baolu.lu@linux.intel.com \
    --cc=deepadinamani@google.com \
    --cc=dwmw2@infradead.org \
    --cc=hskinnemoen@google.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mdf@kernel.org \
    --cc=yonghyun@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.