ACK: [PATCH][Trusty][SRU] iommu/vt-d: Fix missing IOTLB flush in intel_iommu_unmap()

[Colin Ian King]

On 09/06/17 20:27, Jay Vosburgh wrote:
> From: David Woodhouse <dwmw2 at infradead.org>
> 
> BugLink:  https://bugs.launchpad.net/bugs/1697053
> 
> Based on commit ea8ea460c9ace60bbb5ac6e5521d637d5c15293d upstream
> 
> This missing IOTLB flush was added as a minor, inconsequential bug-fix
> in commit ea8ea460c ("iommu/vt-d: Clean up and fix page table clear/free
> behaviour") in 3.15. It wasn't originally intended for -stable but a
> couple of users have reported issues which turn out to be fixed by
> adding the missing flush.
> 
> Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
> (cherry picked from 51d20e1096a711f8cfa9d98a3ac2dd2c7c0fc20c 3.14.y)
> Signed-off-by: Jay Vosburgh <jay.vosburgh at canonical.com>
> 
> ---
>  drivers/iommu/intel-iommu.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 18b3f7cb6ee3..76edfb2b03c8 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -4113,7 +4113,7 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
>  			     unsigned long iova, size_t size)
>  {
>  	struct dmar_domain *dmar_domain = domain->priv;
> -	int order;
> +	int order, iommu_id;
>  
>  	order = dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
>  			    (iova + size - 1) >> VTD_PAGE_SHIFT);
> @@ -4121,6 +4121,22 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
>  	if (dmar_domain->max_addr == iova + size)
>  		dmar_domain->max_addr = iova;
>  
> +	for_each_set_bit(iommu_id, dmar_domain->iommu_bmp, g_num_of_iommus) {
> +		struct intel_iommu *iommu = g_iommus[iommu_id];
> +		int num, ndomains;
> +
> +		/*
> +		 * find bit position of dmar_domain
> +		 */
> +		ndomains = cap_ndoms(iommu->cap);
> +		for_each_set_bit(num, iommu->domain_ids, ndomains) {
> +			if (iommu->domains[num] == dmar_domain)
> +				iommu_flush_iotlb_psi(iommu, num,
> +						      iova >> VTD_PAGE_SHIFT,
> +						      1 << order, 0);
> +		}
> +	}
> +
>  	return PAGE_SIZE << order;
>  }
>  
> 
Thanks Jay,

Acked-by: Colin Ian King <colin.king at canonical.com>