Jean,
Page 122 of VT-d spec indicates you can invalidate multiple pages by setting
the Address Mask (AM) field. Will this achieve what you wanted to do?
http://download.intel.com/technology/computing/vptech/Intel(r)_VT_for_Direct_IO.pdf
Allen
-----Original Message-----
From: Jean Guyader [mailto:jean.guyader@xxxxxxxxxxxxx]
Sent: Monday, November 07, 2011 11:42 PM
To: Kay, Allen M
Cc: Jean Guyader; xen-devel@xxxxxxxxxxxxxxxxxxx; Tim (Xen.org)
Subject: Re: [PATCH 1/6] vtd: Refactor iotlb flush code
Allen,
You are probably talking about __intel_iommu_iotlb_flush.
This function takes a range of address to flush. I haven't found a function in
the vtd code to invalidate a range on address without doing a loop of
flush_iotlb_psi, so I thought that the most efficient and quick way to flush a
range would be to use a domain selective invalidation.
Jean
On 08/11 03:10, Kay, Allen M wrote:
> Jean,
>
> The original code does not call iommu_flush_iotlb_dsi(). What is the reason
> the refractored code need to use domain selective invalidation?
>
> Allen
> -----
>
> + if ( page_count > 1 || gfn == -1 )
> + {
> + if ( iommu_flush_iotlb_dsi(iommu, iommu_domid,
> + 0, flush_dev_iotlb) )
> + iommu_flush_write_buffer(iommu);
> + }
> + else
> + {
> + if ( iommu_flush_iotlb_psi(iommu, iommu_domid,
> + (paddr_t)gfn << PAGE_SHIFT_4K, 0,
> + !dma_old_pte_present, flush_dev_iotlb) )
> + iommu_flush_write_buffer(iommu);
>
> -----Original Message-----
> From: Jean Guyader [mailto:jean.guyader@xxxxxxxxxxxxx]
> Sent: Monday, November 07, 2011 10:25 AM
> To: xen-devel@xxxxxxxxxxxxxxxxxxx
> Cc: tim@xxxxxxx; Kay, Allen M; Jean Guyader
> Subject: [PATCH 1/6] vtd: Refactor iotlb flush code
>
>
> Factorize the iotlb flush code from map_page and unmap_page into it's own
> function.
>
> Signed-off-by: Jean Guyader <jean.guyader@xxxxxxxxxxxxx>
> ---
> xen/drivers/passthrough/vtd/iommu.c | 86 +++++++++++++++++-----------------
> 1 files changed, 43 insertions(+), 43 deletions(-)
>
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