2023-09-22 16:38:16

by Hector Martin

[permalink] [raw]
Subject: [PATCH REGRESSION v2] iommu/apple-dart: Handle DMA_FQ domains in attach_dev()

Commit a4fdd9762272 ("iommu: Use flush queue capability") hid the
IOMMU_DOMAIN_DMA_FQ domain type from domain allocation. A check was
introduced in iommu_dma_init_domain() to fall back if not supported, but
this check runs too late: by that point, devices have been attached to
the IOMMU, and apple-dart's attach_dev() callback does not expect
IOMMU_DOMAIN_DMA_FQ domains.

Change the logic so the IOMMU_DOMAIN_DMA codepath is the default,
instead of explicitly enumerating all types.

Fixes an apple-dart regression in v6.5.

Cc: [email protected]
Cc: [email protected]
Suggested-by: Robin Murphy <[email protected]>
Fixes: a4fdd9762272 ("iommu: Use flush queue capability")
Signed-off-by: Hector Martin <[email protected]>
---
Changes in v2:
- Fixed the issue in apple-dart instead of the iommu core, per Robin's
suggestion.
- Link to v1: https://lore.kernel.org/r/[email protected]
---
drivers/iommu/apple-dart.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 2082081402d3..0b8927508427 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -671,8 +671,7 @@ static int apple_dart_attach_dev(struct iommu_domain *domain,
return ret;

switch (domain->type) {
- case IOMMU_DOMAIN_DMA:
- case IOMMU_DOMAIN_UNMANAGED:
+ default:
ret = apple_dart_domain_add_streams(dart_domain, cfg);
if (ret)
return ret;

---
base-commit: ce9ecca0238b140b88f43859b211c9fdfd8e5b70
change-id: 20230922-iommu-type-regression-25b4f43df770

Best regards,
--
Hector Martin <[email protected]>


2023-09-22 16:45:26

by Neal Gompa

[permalink] [raw]
Subject: Re: [PATCH REGRESSION v2] iommu/apple-dart: Handle DMA_FQ domains in attach_dev()

On Fri, Sep 22, 2023 at 10:55 AM Hector Martin <[email protected]> wrote:
>
> Commit a4fdd9762272 ("iommu: Use flush queue capability") hid the
> IOMMU_DOMAIN_DMA_FQ domain type from domain allocation. A check was
> introduced in iommu_dma_init_domain() to fall back if not supported, but
> this check runs too late: by that point, devices have been attached to
> the IOMMU, and apple-dart's attach_dev() callback does not expect
> IOMMU_DOMAIN_DMA_FQ domains.
>
> Change the logic so the IOMMU_DOMAIN_DMA codepath is the default,
> instead of explicitly enumerating all types.
>
> Fixes an apple-dart regression in v6.5.
>
> Cc: [email protected]
> Cc: [email protected]
> Suggested-by: Robin Murphy <[email protected]>
> Fixes: a4fdd9762272 ("iommu: Use flush queue capability")
> Signed-off-by: Hector Martin <[email protected]>
> ---
> Changes in v2:
> - Fixed the issue in apple-dart instead of the iommu core, per Robin's
> suggestion.
> - Link to v1: https://lore.kernel.org/r/[email protected]
> ---
> drivers/iommu/apple-dart.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
> index 2082081402d3..0b8927508427 100644
> --- a/drivers/iommu/apple-dart.c
> +++ b/drivers/iommu/apple-dart.c
> @@ -671,8 +671,7 @@ static int apple_dart_attach_dev(struct iommu_domain *domain,
> return ret;
>
> switch (domain->type) {
> - case IOMMU_DOMAIN_DMA:
> - case IOMMU_DOMAIN_UNMANAGED:
> + default:
> ret = apple_dart_domain_add_streams(dart_domain, cfg);
> if (ret)
> return ret;
>
> ---
> base-commit: ce9ecca0238b140b88f43859b211c9fdfd8e5b70
> change-id: 20230922-iommu-type-regression-25b4f43df770
>
> Best regards,
> --
> Hector Martin <[email protected]>
>

Looks good to me.

Reviewed-by: Neal Gompa <[email protected]>


--
真実はいつも一つ!/ Always, there's only one truth!

2023-09-22 23:57:28

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH REGRESSION v2] iommu/apple-dart: Handle DMA_FQ domains in attach_dev()

On Fri, Sep 22, 2023 at 11:55:23PM +0900, Hector Martin wrote:
> Commit a4fdd9762272 ("iommu: Use flush queue capability") hid the
> IOMMU_DOMAIN_DMA_FQ domain type from domain allocation. A check was
> introduced in iommu_dma_init_domain() to fall back if not supported, but
> this check runs too late: by that point, devices have been attached to
> the IOMMU, and apple-dart's attach_dev() callback does not expect
> IOMMU_DOMAIN_DMA_FQ domains.
>
> Change the logic so the IOMMU_DOMAIN_DMA codepath is the default,
> instead of explicitly enumerating all types.
>
> Fixes an apple-dart regression in v6.5.
>
> Cc: [email protected]
> Cc: [email protected]
> Suggested-by: Robin Murphy <[email protected]>
> Fixes: a4fdd9762272 ("iommu: Use flush queue capability")
> Signed-off-by: Hector Martin <[email protected]>
> ---
> Changes in v2:
> - Fixed the issue in apple-dart instead of the iommu core, per Robin's
> suggestion.
> - Link to v1: https://lore.kernel.org/r/[email protected]
> ---
> drivers/iommu/apple-dart.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)

Reviewed-by: Jason Gunthorpe <[email protected]>

It is weird looking, but I have a followup series that will clean it -
this should go to -rc

Thanks,
Jason

2023-09-26 23:25:15

by Joerg Roedel

[permalink] [raw]
Subject: Re: [PATCH REGRESSION v2] iommu/apple-dart: Handle DMA_FQ domains in attach_dev()

On Fri, Sep 22, 2023 at 11:55:23PM +0900, Hector Martin wrote:
> ---
> Changes in v2:
> - Fixed the issue in apple-dart instead of the iommu core, per Robin's
> suggestion.
> - Link to v1: https://lore.kernel.org/r/[email protected]
> ---
> drivers/iommu/apple-dart.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)

Applied for v6.6, thanks.