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


Groups > linux.kernel > #1723338

Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry

From Joerg Roedel <joro@8bytes.org>
Newsgroups linux.kernel
Subject Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry
Date 2017-08-30 15:40 +0200
Message-ID <ukbnP-rR-3@gated-at.bofh.it> (permalink)
References <ujt3s-6CP-9@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Hi Filippo,

please change the subject to:

	iommu/vt-d: Don't be too aggressive when clearing one context entry

to follow the convention used in the iommu-tree. Another comment below.

On Mon, Aug 28, 2017 at 04:16:29PM +0200, Filippo Sironi wrote:
>  static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn)
>  {
> +	unsigned long flags;
> +	struct context_entry *context;
> +	u16 did_old;
> +
>  	if (!iommu)
>  		return;
>  
> +	spin_lock_irqsave(&iommu->lock, flags);
> +	context = iommu_context_addr(iommu, bus, devfn, 0);
> +	if (!context) {
> +		spin_unlock_irqrestore(&iommu->lock, flags);
> +		return;
> +	}
> +	did_old = context_domain_id(context);
> +	spin_unlock_irqrestore(&iommu->lock, flags);
>  	clear_context_table(iommu, bus, devfn);

This function is the only caller of clear_context_table(), which does
similar things (like fetching the context-entry) as you are adding
above.

So you can either make clear_context_table() return the old domain-id
so that you don't need to do it here, or you get rid of the function
entirely and add the context_clear_entry() and __iommu_flush_cache()
calls into this code-path.

Regards,

	Joerg

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


Thread

[PATCH] intel-iommu: Don't be too aggressive when clearing one context entry Filippo Sironi <sironi@amazon.de> - 2017-08-28 16:20 +0200
  Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one  context entry Joerg Roedel <joro@8bytes.org> - 2017-08-30 15:40 +0200
    Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one  context entry "Sironi, Filippo" <sironi@amazon.de> - 2017-08-31 10:50 +0200
  Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one  context entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2017-08-30 17:50 +0200
    Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one  context entry "Sironi, Filippo" <sironi@amazon.de> - 2017-08-31 10:50 +0200
  [PATCH v2] iommu/vt-d: Don't be too aggressive when clearing one context entry Filippo Sironi <sironi@amazon.de> - 2017-08-31 11:10 +0200
    Re: [PATCH v2] iommu/vt-d: Don't be too aggressive when clearing one  context entry Joerg Roedel <joro@8bytes.org> - 2017-09-01 11:40 +0200

csiph-web