Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1691470

Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS

From Robin Murphy <robin.murphy@arm.com>
Newsgroups linux.kernel
Subject Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS
Date 2017-07-19 13:00 +0200
Message-ID <u4URX-7qy-7@gated-at.bofh.it> (permalink)
References <u4TCy-6D1-9@gated-at.bofh.it> <u4TCz-6D1-39@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On 19/07/17 10:33, Anup Patel wrote:
> Some of the IOMMUs (such as ARM SMMU) are capable of bypassing
> transactions for which no IOMMU domain is configured.
> 
> This patch adds IOMMU_CAP_BYPASS which can be used by IOMMU
> drivers to advertise transation bypass capability of an IOMMU.

Whatever the intended semantics of this are, I can't help thinking it
would be better served by allowing callers to explicitly allocate their
own IOMMU_DOMAIN_IDENTITY domains. That would also be useful for the
problem we have with legacy virtio devices behind real IOMMUs.

Robin.

> Signed-off-by: Anup Patel <anup.patel@broadcom.com>
> ---
>  include/linux/iommu.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 2cb54ad..6bbb4cc 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -101,6 +101,10 @@ enum iommu_cap {
>  					   transactions */
>  	IOMMU_CAP_INTR_REMAP,		/* IOMMU supports interrupt isolation */
>  	IOMMU_CAP_NOEXEC,		/* IOMMU_NOEXEC flag */
> +	IOMMU_CAP_BYPASS,		/*
> +					 * IOMMU can bypass transactions for
> +					 * which domain is not configured
> +					 */
>  };
>  
>  /*
> 

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 0/5] FlexRM support in VFIO platform Anup Patel <anup.patel@broadcom.com> - 2017-07-19 11:40 +0200
  [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 11:40 +0200
    Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:00 +0200
      Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:20 +0200
        Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:30 +0200
        Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Will Deacon <will.deacon@arm.com> - 2017-07-19 13:30 +0200
          Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:30 +0200
            Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:40 +0200
            Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Will Deacon <will.deacon@arm.com> - 2017-07-19 13:40 +0200
  [PATCH 2/5] iommu/arm-smmu: add IOMMU_CAP_BYPASS to the ARM SMMU driver Anup Patel <anup.patel@broadcom.com> - 2017-07-19 11:40 +0200
    Re: [PATCH 2/5] iommu/arm-smmu: add IOMMU_CAP_BYPASS to the ARM SMMU  driver Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:00 +0200
  Re: [PATCH 0/5] FlexRM support in VFIO platform Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:00 +0200
    Re: [PATCH 0/5] FlexRM support in VFIO platform Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:20 +0200
      Re: [PATCH 0/5] FlexRM support in VFIO platform Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:30 +0200
        Re: [PATCH 0/5] FlexRM support in VFIO platform Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:30 +0200

csiph-web