Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1642787 > unrolled thread
| Started by | Auger Eric <eric.auger@redhat.com> |
|---|---|
| First post | 2017-05-16 22:00 +0200 |
| Last post | 2017-05-16 22:30 +0200 |
| Articles | 3 — 2 participants |
Back to article view | Back to linux.kernel
This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by
below is the oldest one visible, not the original post.
Re: [PATCH] iommu/dma: Setup iova_domain granule for IOMMU_DMA_MSI cookies Auger Eric <eric.auger@redhat.com> - 2017-05-16 22:00 +0200
Re: [PATCH] iommu/dma: Setup iova_domain granule for IOMMU_DMA_MSI cookies Nate Watterson <nwatters@codeaurora.org> - 2017-05-16 22:10 +0200
Re: [PATCH] iommu/dma: Setup iova_domain granule for IOMMU_DMA_MSI cookies Auger Eric <eric.auger@redhat.com> - 2017-05-16 22:30 +0200
| From | Auger Eric <eric.auger@redhat.com> |
|---|---|
| Date | 2017-05-16 22:00 +0200 |
| Subject | Re: [PATCH] iommu/dma: Setup iova_domain granule for IOMMU_DMA_MSI cookies |
| Message-ID | <tHQNr-1oA-11@gated-at.bofh.it> |
Hi,
On 13/04/2017 21:38, Nate Watterson wrote:
> Hi Robin,
>
> On 4/13/2017 7:21 AM, Robin Murphy wrote:
>> Hi Nate,
>>
>> On 13/04/17 09:55, Nate Watterson wrote:
>>> Currently, the __iommu_dma_{map/free} functions call iova_{offset/align}
>>> making them unsuitable for use with iommu_domains having an
>>> IOMMU_DMA_MSI
>>> cookie since the cookie's iova_domain member, iovad, is uninitialized.
>>>
>>> Now that iommu_dma_get_msi_page() calls __iommu_dma_map() regardless
>>> of cookie type, failures are being seen when mapping MSI target
>>> addresses for devices attached to UNMANAGED domains. To work around
>>> this issue, the iova_domain granule for IOMMU_DMA_MSI cookies is
>>> initialized to the value returned by cookie_msi_granule().
>>
>> Oh bum. Thanks for the report.
>>
>> However, I really don't like bodging around it with deliberate undefined
>> behaviour. Fixing things properly doesn't seem too hard:
>
> I was not especially please with my solution, but I wanted to avoid
> potentially missing any other spots in the code where granule was
> used uninitialized. The compile time check made me feel a little
> less dirty about innappropriately using the iova_domain with MSI
> cookies.
>
>>
>> ----->8-----
>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>> index 8348f366ddd1..62618e77bedc 100644
>> --- a/drivers/iommu/dma-iommu.c
>> +++ b/drivers/iommu/dma-iommu.c
>> @@ -396,13 +396,13 @@ static void iommu_dma_free_iova(struct
>> iommu_dma_cookie *cookie,
>> dma_addr_t iova, size_t size)
>> {
>> struct iova_domain *iovad = &cookie->iovad;
>> - unsigned long shift = iova_shift(iovad);
>>
>> /* The MSI case is only ever cleaning up its most recent
>> allocation */
>> if (cookie->type == IOMMU_DMA_MSI_COOKIE)
>> cookie->msi_iova -= size;
>> else
>> - free_iova_fast(iovad, iova >> shift, size >> shift);
>> + free_iova_fast(iovad, iova_pfn(iovad, iova),
>> + size >> iova_shift(iovad));
>> }
>>
>> static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t
>> dma_addr,
>> @@ -617,11 +617,14 @@ static dma_addr_t __iommu_dma_map(struct device
>> *dev, phys_addr_t phys,
>> {
>> struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
>> struct iommu_dma_cookie *cookie = domain->iova_cookie;
>> - struct iova_domain *iovad = &cookie->iovad;
>> - size_t iova_off = iova_offset(iovad, phys);
>> + size_t iova_off = 0;
>> dma_addr_t iova;
>>
>> - size = iova_align(iovad, size + iova_off);
>> + if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
>> + iova_off = iova_offset(&cookie->iovad, phys);
>> + size = iova_align(&cookie->iovad, size + iova_off);
>> + }
>> +
>> iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev),
>> dev);
>> if (!iova)
>> return DMA_ERROR_CODE;
>> -----8<-----
>>
>> Untested, and you'll probably want to double-check it anyway given that
>> the original oversight was mine in the first place ;)
>
> This looks good to me. As Shanker has already mentioned, it does fix the
> faults we were previously seeing with direct device assignment. I also
> verified that there aren't any other obvious cases of a granule == 0
> being used in the dma_iommu code by adding BUG_ON(!iovad->granule) to
> iova_{mask/align/offset/...} and running a variety of tests without
> issue.
>
> Are you going to post the patch?
I also noticed PCIe passthrough/ARM is broken for me with 4.12-r1. I
tested Robin's patch as well, on Cavium ThunderX, and this fixes the
faults I have seen.
Has anyone sent a formal patch?
Thanks
Eric
>
>>
>> Robin.
>>
>>> Fixes: a44e6657585b ("iommu/dma: Clean up MSI IOVA allocation")
>>> Signed-off-by: Nate Watterson <nwatters@codeaurora.org>
>>> ---
>>> drivers/iommu/dma-iommu.c | 10 ++++++++++
>>> 1 file changed, 10 insertions(+)
>>>
>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>> index 8348f366..d7b0816 100644
>>> --- a/drivers/iommu/dma-iommu.c
>>> +++ b/drivers/iommu/dma-iommu.c
>>> @@ -127,6 +127,16 @@ int iommu_get_msi_cookie(struct iommu_domain
>>> *domain, dma_addr_t base)
>>> cookie->msi_iova = base;
>>> domain->iova_cookie = cookie;
>>> +
>>> + /*
>>> + * Setup granule for compatibility with __iommu_dma_{alloc/free}
>>> and
>>> + * add a compile time check to ensure that writing granule won't
>>> + * clobber msi_iova.
>>> + */
>>> + cookie->iovad.granule = cookie_msi_granule(cookie);
>>> + BUILD_BUG_ON(offsetof(struct iova_domain, granule) <
>>> + sizeof(cookie->msi_iova));
>>> +
>>> return 0;
>>> }
>>> EXPORT_SYMBOL(iommu_get_msi_cookie);
>>>
>>
[toc] | [next] | [standalone]
| From | Nate Watterson <nwatters@codeaurora.org> |
|---|---|
| Date | 2017-05-16 22:10 +0200 |
| Message-ID | <tHQX8-1J7-5@gated-at.bofh.it> |
| In reply to | #1642787 |
On 5/16/2017 3:55 PM, Auger Eric wrote:
> Hi,
>
> On 13/04/2017 21:38, Nate Watterson wrote:
>> Hi Robin,
>>
>> On 4/13/2017 7:21 AM, Robin Murphy wrote:
>>> Hi Nate,
>>>
>>> On 13/04/17 09:55, Nate Watterson wrote:
>>>> Currently, the __iommu_dma_{map/free} functions call iova_{offset/align}
>>>> making them unsuitable for use with iommu_domains having an
>>>> IOMMU_DMA_MSI
>>>> cookie since the cookie's iova_domain member, iovad, is uninitialized.
>>>>
>>>> Now that iommu_dma_get_msi_page() calls __iommu_dma_map() regardless
>>>> of cookie type, failures are being seen when mapping MSI target
>>>> addresses for devices attached to UNMANAGED domains. To work around
>>>> this issue, the iova_domain granule for IOMMU_DMA_MSI cookies is
>>>> initialized to the value returned by cookie_msi_granule().
>>>
>>> Oh bum. Thanks for the report.
>>>
>>> However, I really don't like bodging around it with deliberate undefined
>>> behaviour. Fixing things properly doesn't seem too hard:
>>
>> I was not especially please with my solution, but I wanted to avoid
>> potentially missing any other spots in the code where granule was
>> used uninitialized. The compile time check made me feel a little
>> less dirty about innappropriately using the iova_domain with MSI
>> cookies.
>>
>>>
>>> ----->8-----
>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>> index 8348f366ddd1..62618e77bedc 100644
>>> --- a/drivers/iommu/dma-iommu.c
>>> +++ b/drivers/iommu/dma-iommu.c
>>> @@ -396,13 +396,13 @@ static void iommu_dma_free_iova(struct
>>> iommu_dma_cookie *cookie,
>>> dma_addr_t iova, size_t size)
>>> {
>>> struct iova_domain *iovad = &cookie->iovad;
>>> - unsigned long shift = iova_shift(iovad);
>>>
>>> /* The MSI case is only ever cleaning up its most recent
>>> allocation */
>>> if (cookie->type == IOMMU_DMA_MSI_COOKIE)
>>> cookie->msi_iova -= size;
>>> else
>>> - free_iova_fast(iovad, iova >> shift, size >> shift);
>>> + free_iova_fast(iovad, iova_pfn(iovad, iova),
>>> + size >> iova_shift(iovad));
>>> }
>>>
>>> static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t
>>> dma_addr,
>>> @@ -617,11 +617,14 @@ static dma_addr_t __iommu_dma_map(struct device
>>> *dev, phys_addr_t phys,
>>> {
>>> struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
>>> struct iommu_dma_cookie *cookie = domain->iova_cookie;
>>> - struct iova_domain *iovad = &cookie->iovad;
>>> - size_t iova_off = iova_offset(iovad, phys);
>>> + size_t iova_off = 0;
>>> dma_addr_t iova;
>>>
>>> - size = iova_align(iovad, size + iova_off);
>>> + if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
>>> + iova_off = iova_offset(&cookie->iovad, phys);
>>> + size = iova_align(&cookie->iovad, size + iova_off);
>>> + }
>>> +
>>> iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev),
>>> dev);
>>> if (!iova)
>>> return DMA_ERROR_CODE;
>>> -----8<-----
>>>
>>> Untested, and you'll probably want to double-check it anyway given that
>>> the original oversight was mine in the first place ;)
>>
>> This looks good to me. As Shanker has already mentioned, it does fix the
>> faults we were previously seeing with direct device assignment. I also
>> verified that there aren't any other obvious cases of a granule == 0
>> being used in the dma_iommu code by adding BUG_ON(!iovad->granule) to
>> iova_{mask/align/offset/...} and running a variety of tests without
>> issue.
>>
>> Are you going to post the patch?
>
> I also noticed PCIe passthrough/ARM is broken for me with 4.12-r1. I
> tested Robin's patch as well, on Cavium ThunderX, and this fixes the
> faults I have seen.
>
> Has anyone sent a formal patch?
iommu/dma: Don't touch invalid iova_domain members
>
> Thanks
>
> Eric
>
>>
>>>
>>> Robin.
>>>
>>>> Fixes: a44e6657585b ("iommu/dma: Clean up MSI IOVA allocation")
>>>> Signed-off-by: Nate Watterson <nwatters@codeaurora.org>
>>>> ---
>>>> drivers/iommu/dma-iommu.c | 10 ++++++++++
>>>> 1 file changed, 10 insertions(+)
>>>>
>>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>>> index 8348f366..d7b0816 100644
>>>> --- a/drivers/iommu/dma-iommu.c
>>>> +++ b/drivers/iommu/dma-iommu.c
>>>> @@ -127,6 +127,16 @@ int iommu_get_msi_cookie(struct iommu_domain
>>>> *domain, dma_addr_t base)
>>>> cookie->msi_iova = base;
>>>> domain->iova_cookie = cookie;
>>>> +
>>>> + /*
>>>> + * Setup granule for compatibility with __iommu_dma_{alloc/free}
>>>> and
>>>> + * add a compile time check to ensure that writing granule won't
>>>> + * clobber msi_iova.
>>>> + */
>>>> + cookie->iovad.granule = cookie_msi_granule(cookie);
>>>> + BUILD_BUG_ON(offsetof(struct iova_domain, granule) <
>>>> + sizeof(cookie->msi_iova));
>>>> +
>>>> return 0;
>>>> }
>>>> EXPORT_SYMBOL(iommu_get_msi_cookie);
>>>>
>>>
--
Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
[toc] | [prev] | [next] | [standalone]
| From | Auger Eric <eric.auger@redhat.com> |
|---|---|
| Date | 2017-05-16 22:30 +0200 |
| Message-ID | <tHRgu-1Pj-21@gated-at.bofh.it> |
| In reply to | #1642791 |
Hi Nate,
On 16/05/2017 22:07, Nate Watterson wrote:
>
>
> On 5/16/2017 3:55 PM, Auger Eric wrote:
>> Hi,
>>
>> On 13/04/2017 21:38, Nate Watterson wrote:
>>> Hi Robin,
>>>
>>> On 4/13/2017 7:21 AM, Robin Murphy wrote:
>>>> Hi Nate,
>>>>
>>>> On 13/04/17 09:55, Nate Watterson wrote:
>>>>> Currently, the __iommu_dma_{map/free} functions call
>>>>> iova_{offset/align}
>>>>> making them unsuitable for use with iommu_domains having an
>>>>> IOMMU_DMA_MSI
>>>>> cookie since the cookie's iova_domain member, iovad, is uninitialized.
>>>>>
>>>>> Now that iommu_dma_get_msi_page() calls __iommu_dma_map() regardless
>>>>> of cookie type, failures are being seen when mapping MSI target
>>>>> addresses for devices attached to UNMANAGED domains. To work around
>>>>> this issue, the iova_domain granule for IOMMU_DMA_MSI cookies is
>>>>> initialized to the value returned by cookie_msi_granule().
>>>>
>>>> Oh bum. Thanks for the report.
>>>>
>>>> However, I really don't like bodging around it with deliberate
>>>> undefined
>>>> behaviour. Fixing things properly doesn't seem too hard:
>>>
>>> I was not especially please with my solution, but I wanted to avoid
>>> potentially missing any other spots in the code where granule was
>>> used uninitialized. The compile time check made me feel a little
>>> less dirty about innappropriately using the iova_domain with MSI
>>> cookies.
>>>
>>>>
>>>> ----->8-----
>>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>>> index 8348f366ddd1..62618e77bedc 100644
>>>> --- a/drivers/iommu/dma-iommu.c
>>>> +++ b/drivers/iommu/dma-iommu.c
>>>> @@ -396,13 +396,13 @@ static void iommu_dma_free_iova(struct
>>>> iommu_dma_cookie *cookie,
>>>> dma_addr_t iova, size_t size)
>>>> {
>>>> struct iova_domain *iovad = &cookie->iovad;
>>>> - unsigned long shift = iova_shift(iovad);
>>>>
>>>> /* The MSI case is only ever cleaning up its most recent
>>>> allocation */
>>>> if (cookie->type == IOMMU_DMA_MSI_COOKIE)
>>>> cookie->msi_iova -= size;
>>>> else
>>>> - free_iova_fast(iovad, iova >> shift, size >> shift);
>>>> + free_iova_fast(iovad, iova_pfn(iovad, iova),
>>>> + size >> iova_shift(iovad));
>>>> }
>>>>
>>>> static void __iommu_dma_unmap(struct iommu_domain *domain,
>>>> dma_addr_t
>>>> dma_addr,
>>>> @@ -617,11 +617,14 @@ static dma_addr_t __iommu_dma_map(struct device
>>>> *dev, phys_addr_t phys,
>>>> {
>>>> struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
>>>> struct iommu_dma_cookie *cookie = domain->iova_cookie;
>>>> - struct iova_domain *iovad = &cookie->iovad;
>>>> - size_t iova_off = iova_offset(iovad, phys);
>>>> + size_t iova_off = 0;
>>>> dma_addr_t iova;
>>>>
>>>> - size = iova_align(iovad, size + iova_off);
>>>> + if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
>>>> + iova_off = iova_offset(&cookie->iovad, phys);
>>>> + size = iova_align(&cookie->iovad, size + iova_off);
>>>> + }
>>>> +
>>>> iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev),
>>>> dev);
>>>> if (!iova)
>>>> return DMA_ERROR_CODE;
>>>> -----8<-----
>>>>
>>>> Untested, and you'll probably want to double-check it anyway given that
>>>> the original oversight was mine in the first place ;)
>>>
>>> This looks good to me. As Shanker has already mentioned, it does fix the
>>> faults we were previously seeing with direct device assignment. I also
>>> verified that there aren't any other obvious cases of a granule == 0
>>> being used in the dma_iommu code by adding BUG_ON(!iovad->granule) to
>>> iova_{mask/align/offset/...} and running a variety of tests without
>>> issue.
>>>
>>> Are you going to post the patch?
>>
>> I also noticed PCIe passthrough/ARM is broken for me with 4.12-r1. I
>> tested Robin's patch as well, on Cavium ThunderX, and this fixes the
>> faults I have seen.
>>
>> Has anyone sent a formal patch?
>
> iommu/dma: Don't touch invalid iova_domain members
thanks!
Best Regards
Eric
>
>>
>> Thanks
>>
>> Eric
>>
>>>
>>>>
>>>> Robin.
>>>>
>>>>> Fixes: a44e6657585b ("iommu/dma: Clean up MSI IOVA allocation")
>>>>> Signed-off-by: Nate Watterson <nwatters@codeaurora.org>
>>>>> ---
>>>>> drivers/iommu/dma-iommu.c | 10 ++++++++++
>>>>> 1 file changed, 10 insertions(+)
>>>>>
>>>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>>>> index 8348f366..d7b0816 100644
>>>>> --- a/drivers/iommu/dma-iommu.c
>>>>> +++ b/drivers/iommu/dma-iommu.c
>>>>> @@ -127,6 +127,16 @@ int iommu_get_msi_cookie(struct iommu_domain
>>>>> *domain, dma_addr_t base)
>>>>> cookie->msi_iova = base;
>>>>> domain->iova_cookie = cookie;
>>>>> +
>>>>> + /*
>>>>> + * Setup granule for compatibility with __iommu_dma_{alloc/free}
>>>>> and
>>>>> + * add a compile time check to ensure that writing granule won't
>>>>> + * clobber msi_iova.
>>>>> + */
>>>>> + cookie->iovad.granule = cookie_msi_granule(cookie);
>>>>> + BUILD_BUG_ON(offsetof(struct iova_domain, granule) <
>>>>> + sizeof(cookie->msi_iova));
>>>>> +
>>>>> return 0;
>>>>> }
>>>>> EXPORT_SYMBOL(iommu_get_msi_cookie);
>>>>>
>>>>
>
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web