On Thu, Sep 15, 2016 at 11:03:26PM +0800, Baoquan He wrote:
> All devices are supposed to reset themselves at device driver initialization
> stage. At this time if in kdump kernel those on-flight DMA will be stopped
> because of device reset. It's best time to update the protection domain info,
> especially pte_root, to dte entry which the device relates to.
>
> Signed-off-by: Baoquan He <b...@redhat.com>
> ---
> drivers/iommu/amd_iommu.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index 6c37300..00b64ee 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -2310,6 +2310,10 @@ static dma_addr_t __map_single(struct device *dev,
> unsigned int pages;
> int prot = 0;
> int i;
> + struct iommu_dev_data *dev_data = get_dev_data(dev);
> + struct protection_domain *domain = get_domain(dev);
> + u16 alias = amd_iommu_alias_table[dev_data->devid];
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[dev_data->devid];
>
> pages = iommu_num_pages(paddr, size, PAGE_SIZE);
> paddr &= PAGE_MASK;
> @@ -2319,6 +2323,13 @@ static dma_addr_t __map_single(struct device *dev,
> goto out;
>
> prot = dir2prot(direction);
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated) {
> + dev_data->domain_updated = true;
> + set_dte_entry(dev_data->devid, domain, dev_data->ats.enabled);
> + if (alias != dev_data->devid)
> + set_dte_entry(alias, domain, dev_data->ats.enabled);
> + device_flush_dte(dev_data);
> + }
Hmm, have you tried hooking this into the set_dma_mask call-back? Every
driver should call it for its device, so that should be a better
indicator to now map a new domain.
Joerg
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