From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Jean-Philippe Brucker <jean-philippe@linaro.com>,
Christoph Hellwig <hch@infradead.org>,
Yi Liu <yi.l.liu@intel.com>, Raj Ashok <ashok.raj@intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Dave Jiang <dave.jiang@intel.com>,
wangzhou1@hisilicon.com, zhangfei.gao@linaro.org,
vkoul@kernel.org
Subject: Re: [PATCH v4 1/2] iommu/sva: Tighten SVA bind API with explicit flags
Date: Wed, 12 May 2021 12:18:08 +0200 [thread overview]
Message-ID: <YJurYOz264HKm4Bz@myrica> (raw)
In-Reply-To: <1620653108-44901-2-git-send-email-jacob.jun.pan@linux.intel.com>
On Mon, May 10, 2021 at 06:25:07AM -0700, Jacob Pan wrote:
> The void* drvdata parameter isn't really used in iommu_sva_bind_device()
> API, the current IDXD code "borrows" the drvdata for a VT-d private flag
> for supervisor SVA usage.
>
> Supervisor/Privileged mode request is a generic feature. It should be
> promoted from the VT-d vendor driver to the generic code.
>
> This patch replaces void* drvdata with a unsigned int flags parameter
> and adjusts callers accordingly.
>
> Link: https://lore.kernel.org/linux-iommu/YFhiMLR35WWMW%2FHu@myrica/
> Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Thanks for cleaning this up. Whether Vt-d's supervisor mode will need
rework or not, this is still good to have. One nit below if you resend
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
[...]
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 32d448050bf7..fcc9d36b4b01 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -152,6 +152,19 @@ enum iommu_dev_features {
>
> #define IOMMU_PASID_INVALID (-1U)
>
> +/*
> + * The IOMMU_SVA_BIND_SUPERVISOR flag requests a PASID which can be used only
> + * for access to kernel addresses. No IOTLB flushes are automatically done
> + * for kernel mappings; it is valid only for access to the kernel's static
> + * 1:1 mapping of physical memory — not to vmalloc or even module mappings.
> + * A future API addition may permit the use of such ranges, by means of an
> + * explicit IOTLB flush call (akin to the DMA API's unmap method).
> + *
> + * It is unlikely that we will ever hook into flush_tlb_kernel_range() to
> + * do such IOTLB flushes automatically.
I would add that this is platform specific and not all IOMMU drivers
support the feature.
Thanks,
Jean
> + */
> +#define IOMMU_SVA_BIND_SUPERVISOR BIT(0)
> +
> #ifdef CONFIG_IOMMU_API
next prev parent reply other threads:[~2021-05-12 10:18 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 13:25 [PATCH v4 0/2] Simplify and restrict IOMMU SVA APIs Jacob Pan
2021-05-10 13:25 ` [PATCH v4 1/2] iommu/sva: Tighten SVA bind API with explicit flags Jacob Pan
2021-05-10 23:37 ` Jason Gunthorpe
2021-05-11 3:31 ` Jacob Pan
2021-05-11 11:48 ` Jason Gunthorpe
2021-05-11 16:14 ` Jacob Pan
2021-05-11 16:35 ` Jason Gunthorpe
2021-05-11 18:05 ` Jacob Pan
2021-05-11 19:47 ` Jason Gunthorpe
2021-05-12 6:37 ` Christoph Hellwig
2021-05-13 13:00 ` Jacob Pan
2021-05-13 13:38 ` Jason Gunthorpe
2021-05-13 15:10 ` Jacob Pan
2021-05-13 16:44 ` Luck, Tony
2021-05-13 17:33 ` Jason Gunthorpe
2021-05-13 18:53 ` Luck, Tony
2021-05-13 19:00 ` Jason Gunthorpe
2021-05-13 19:14 ` Luck, Tony
2021-05-13 19:20 ` Jason Gunthorpe
2021-05-13 19:46 ` Jacob Pan
2021-05-13 19:57 ` Luck, Tony
2021-05-13 20:22 ` Jacob Pan
2021-05-13 22:31 ` Jason Gunthorpe
2021-05-13 23:40 ` Jacob Pan
2021-05-17 14:37 ` Jason Gunthorpe
2021-05-19 15:46 ` Jacob Pan
2021-05-12 10:18 ` Jean-Philippe Brucker [this message]
2021-05-10 13:25 ` [PATCH v4 2/2] iommu/sva: Remove mm parameter from SVA bind API Jacob Pan
2021-05-12 10:24 ` Jean-Philippe Brucker
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