[REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[Lu Baolu]

[ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]

The Access/Dirty bits in the first level page table entry will be set
whenever a page table entry was used for address translation or write
permission was successfully translated. This is always true when using
the first-level page table for kernel IOVA. Instead of wasting hardware
cycles to update the certain bits, it's better to set them up at the
beginning.

Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/intel/iommu.c | 14 ++++++++++++--
 include/linux/intel-iommu.h |  2 ++
 2 files changed, 14 insertions(+), 2 deletions(-)

[Note:
- This is a reworked patch of
  https://lore.kernel.org/stable/20210512144819.664462530@linuxfoundation.org/T/#m65267f0a0091c2fcbde097cea91089775908faad.
- It aims to fix a reported issue of
  https://bugzilla.kernel.org/show_bug.cgi?id=213077.
- Please help to review and test.]

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 3295e5e162a4..33ffbcb53dec 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1028,8 +1028,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 
 			domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
 			pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
-			if (domain_use_first_level(domain))
+			if (domain_use_first_level(domain)) {
 				pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US;
+				if (domain->domain.type == IOMMU_DOMAIN_DMA)
+					pteval |= DMA_FL_PTE_ACCESS;
+			}
 			if (cmpxchg64(&pte->val, 0ULL, pteval))
 				/* Someone else set it while we were thinking; use theirs. */
 				free_pgtable_page(tmp_page);
@@ -2354,9 +2357,16 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 		return -EINVAL;
 
 	attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP);
-	if (domain_use_first_level(domain))
+	if (domain_use_first_level(domain)) {
 		attr |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD | DMA_FL_PTE_US;
 
+		if (domain->domain.type == IOMMU_DOMAIN_DMA) {
+			attr |= DMA_FL_PTE_ACCESS;
+			if (prot & DMA_PTE_WRITE)
+				attr |= DMA_FL_PTE_DIRTY;
+		}
+	}
+
 	if (!sg) {
 		sg_res = nr_pages;
 		pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 94522685a0d9..ccaa057faf8c 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -42,6 +42,8 @@
 
 #define DMA_FL_PTE_PRESENT	BIT_ULL(0)
 #define DMA_FL_PTE_US		BIT_ULL(2)
+#define DMA_FL_PTE_ACCESS	BIT_ULL(5)
+#define DMA_FL_PTE_DIRTY	BIT_ULL(6)
 #define DMA_FL_PTE_XD		BIT_ULL(63)
 
 #define ADDR_WIDTH_5LEVEL	(57)
-- 
2.25.1

Re: [REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[Greg KH]

On Mon, May 17, 2021 at 11:49:13AM +0800, Lu Baolu wrote:
> [ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]
> 
> The Access/Dirty bits in the first level page table entry will be set
> whenever a page table entry was used for address translation or write
> permission was successfully translated. This is always true when using
> the first-level page table for kernel IOVA. Instead of wasting hardware
> cycles to update the certain bits, it's better to set them up at the
> beginning.
> 
> Suggested-by: Ashok Raj <ashok.raj@intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/iommu/intel/iommu.c | 14 ++++++++++++--
>  include/linux/intel-iommu.h |  2 ++
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> [Note:
> - This is a reworked patch of
>   https://lore.kernel.org/stable/20210512144819.664462530@linuxfoundation.org/T/#m65267f0a0091c2fcbde097cea91089775908faad.
> - It aims to fix a reported issue of
>   https://bugzilla.kernel.org/show_bug.cgi?id=213077.
> - Please help to review and test.]

What stable tree(s) is this supposed to be for?

thanks,

greg k-h

Re: [REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[Lu Baolu]

Hi Greg,

On 5/17/21 3:07 PM, Greg KH wrote:
> On Mon, May 17, 2021 at 11:49:13AM +0800, Lu Baolu wrote:
>> [ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]
>>
>> The Access/Dirty bits in the first level page table entry will be set
>> whenever a page table entry was used for address translation or write
>> permission was successfully translated. This is always true when using
>> the first-level page table for kernel IOVA. Instead of wasting hardware
>> cycles to update the certain bits, it's better to set them up at the
>> beginning.
>>
>> Suggested-by: Ashok Raj <ashok.raj@intel.com>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
>> Signed-off-by: Joerg Roedel <jroedel@suse.de>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>>   drivers/iommu/intel/iommu.c | 14 ++++++++++++--
>>   include/linux/intel-iommu.h |  2 ++
>>   2 files changed, 14 insertions(+), 2 deletions(-)
>>
>> [Note:
>> - This is a reworked patch of
>>    https://lore.kernel.org/stable/20210512144819.664462530@linuxfoundation.org/T/#m65267f0a0091c2fcbde097cea91089775908faad.
>> - It aims to fix a reported issue of
>>    https://bugzilla.kernel.org/show_bug.cgi?id=213077.
>> - Please help to review and test.]
> 
> What stable tree(s) is this supposed to be for?

It's for 5.10.37.

> 
> thanks,
> 
> greg k-h
> 

Best regards,
baolu

Re: [REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[Greg KH]

On Mon, May 17, 2021 at 03:17:53PM +0800, Lu Baolu wrote:
> Hi Greg,
> 
> On 5/17/21 3:07 PM, Greg KH wrote:
> > On Mon, May 17, 2021 at 11:49:13AM +0800, Lu Baolu wrote:
> > > [ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]
> > > 
> > > The Access/Dirty bits in the first level page table entry will be set
> > > whenever a page table entry was used for address translation or write
> > > permission was successfully translated. This is always true when using
> > > the first-level page table for kernel IOVA. Instead of wasting hardware
> > > cycles to update the certain bits, it's better to set them up at the
> > > beginning.
> > > 
> > > Suggested-by: Ashok Raj <ashok.raj@intel.com>
> > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> > > Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
> > > Signed-off-by: Joerg Roedel <jroedel@suse.de>
> > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > ---
> > >   drivers/iommu/intel/iommu.c | 14 ++++++++++++--
> > >   include/linux/intel-iommu.h |  2 ++
> > >   2 files changed, 14 insertions(+), 2 deletions(-)
> > > 
> > > [Note:
> > > - This is a reworked patch of
> > >    https://lore.kernel.org/stable/20210512144819.664462530@linuxfoundation.org/T/#m65267f0a0091c2fcbde097cea91089775908faad.
> > > - It aims to fix a reported issue of
> > >    https://bugzilla.kernel.org/show_bug.cgi?id=213077.
> > > - Please help to review and test.]
> > 
> > What stable tree(s) is this supposed to be for?
> 
> It's for 5.10.37.

But the above commit is already in 5.10.y.  And what about 5.11 and
5.12, were those backports incorrect?

confused,

greg k-h

Re: [REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[Lu Baolu]

Hi Greg,

On 5/17/21 3:27 PM, Greg KH wrote:
> On Mon, May 17, 2021 at 03:17:53PM +0800, Lu Baolu wrote:
>> Hi Greg,
>>
>> On 5/17/21 3:07 PM, Greg KH wrote:
>>> On Mon, May 17, 2021 at 11:49:13AM +0800, Lu Baolu wrote:
>>>> [ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]
>>>>
>>>> The Access/Dirty bits in the first level page table entry will be set
>>>> whenever a page table entry was used for address translation or write
>>>> permission was successfully translated. This is always true when using
>>>> the first-level page table for kernel IOVA. Instead of wasting hardware
>>>> cycles to update the certain bits, it's better to set them up at the
>>>> beginning.
>>>>
>>>> Suggested-by: Ashok Raj <ashok.raj@intel.com>
>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>> Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
>>>> Signed-off-by: Joerg Roedel <jroedel@suse.de>
>>>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>>>> ---
>>>>    drivers/iommu/intel/iommu.c | 14 ++++++++++++--
>>>>    include/linux/intel-iommu.h |  2 ++
>>>>    2 files changed, 14 insertions(+), 2 deletions(-)
>>>>
>>>> [Note:
>>>> - This is a reworked patch of
>>>>     https://lore.kernel.org/stable/20210512144819.664462530@linuxfoundation.org/T/#m65267f0a0091c2fcbde097cea91089775908faad.
>>>> - It aims to fix a reported issue of
>>>>     https://bugzilla.kernel.org/show_bug.cgi?id=213077.
>>>> - Please help to review and test.]
>>>
>>> What stable tree(s) is this supposed to be for?
>>
>> It's for 5.10.37.
> 
> But the above commit is already in 5.10.y.  And what about 5.11 and
> 5.12, were those backports incorrect?

Above commit is now only in v5.10.37. Other 5.10.y are not impacted.

5.11 and 5.12 both have correct backports.

> 
> confused,
> 
> greg k-h
> 

Best regards,
baolu

Re: [REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

[Greg KH]

On Mon, May 17, 2021 at 03:51:13PM +0800, Lu Baolu wrote:
> Hi Greg,
> 
> On 5/17/21 3:27 PM, Greg KH wrote:
> > On Mon, May 17, 2021 at 03:17:53PM +0800, Lu Baolu wrote:
> > > Hi Greg,
> > > 
> > > On 5/17/21 3:07 PM, Greg KH wrote:
> > > > On Mon, May 17, 2021 at 11:49:13AM +0800, Lu Baolu wrote:
> > > > > [ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]
> > > > > 
> > > > > The Access/Dirty bits in the first level page table entry will be set
> > > > > whenever a page table entry was used for address translation or write
> > > > > permission was successfully translated. This is always true when using
> > > > > the first-level page table for kernel IOVA. Instead of wasting hardware
> > > > > cycles to update the certain bits, it's better to set them up at the
> > > > > beginning.
> > > > > 
> > > > > Suggested-by: Ashok Raj <ashok.raj@intel.com>
> > > > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> > > > > Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
> > > > > Signed-off-by: Joerg Roedel <jroedel@suse.de>
> > > > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > > > ---
> > > > >    drivers/iommu/intel/iommu.c | 14 ++++++++++++--
> > > > >    include/linux/intel-iommu.h |  2 ++
> > > > >    2 files changed, 14 insertions(+), 2 deletions(-)
> > > > > 
> > > > > [Note:
> > > > > - This is a reworked patch of
> > > > >     https://lore.kernel.org/stable/20210512144819.664462530@linuxfoundation.org/T/#m65267f0a0091c2fcbde097cea91089775908faad.
> > > > > - It aims to fix a reported issue of
> > > > >     https://bugzilla.kernel.org/show_bug.cgi?id=213077.
> > > > > - Please help to review and test.]
> > > > 
> > > > What stable tree(s) is this supposed to be for?
> > > 
> > > It's for 5.10.37.
> > 
> > But the above commit is already in 5.10.y.  And what about 5.11 and
> > 5.12, were those backports incorrect?
> 
> Above commit is now only in v5.10.37. Other 5.10.y are not impacted.
> 
> 5.11 and 5.12 both have correct backports.

Thanks for this, I've reverted the offending commit and added this one
in it's place.

greg k-h