On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> AMD iommu creates protection domain and assign each device to it during
> iommu driver initialization stage. This happened just after system pci
> bus scanning stage, and much earlier than device driver init stage. So
> at this time if in kdump kernel the domain info, especially pte_root,
> can't be updated to dte entry. We should wait until device driver init
> stage.
>
> Signed-off-by: Baoquan He <b...@redhat.com>
> ---
> drivers/iommu/amd_iommu.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index fcb69ff..6c37300 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -137,6 +137,7 @@ struct iommu_dev_data {
> bool pri_tlp; /* PASID TLB required for
> PPR completions */
> u32 errata; /* Bitmap for errata to apply */
> + bool domain_updated;
> };
>
> /*
> @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct
> protection_domain *domain, bool ats)
> {
> u64 pte_root = 0;
> u64 flags = 0;
> + struct iommu_dev_data *dev_data;
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> + dev_data = find_dev_data(devid);
> + if (!dev_data)
> + return;
> +
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> + return;
>
> if (domain->mode != PAGE_MODE_NONE)
> pte_root = virt_to_phys(domain->pt_root);
> @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct
> protection_domain *domain, bool ats)
>
> static void clear_dte_entry(u16 devid)
> {
> + struct iommu_dev_data *dev_data;
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> + dev_data = find_dev_data(devid);
> + if (!dev_data)
> + return;
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> + return;
This should be moved to do_attach/do_detach. There you also already have
the dev_data you need here.
> /* remove entry from the device table seen by the hardware */
> amd_iommu_dev_table[devid].data[0] = DTE_FLAG_V | DTE_FLAG_TV;
> amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> --
> 2.5.5
>
