Hi Sai,

On 7/22/19 1:21 PM, Prakhya, Sai Praneeth wrote:
Hi Allen,

diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-
iommu-debugfs.c
index 73a552914455..e31c3b416351 100644
--- a/drivers/iommu/intel-iommu-debugfs.c
+++ b/drivers/iommu/intel-iommu-debugfs.c
@@ -235,7 +235,7 @@ static void ctx_tbl_walk(struct seq_file *m, struct
intel_iommu *iommu, u16 bus)
                tbl_wlk.ctx_entry = context;
                m->private = &tbl_wlk;

-               if (pasid_supported(iommu) && is_pasid_enabled(context)) {
+               if (dmar_readq(iommu->reg + DMAR_RTADDR_REG) &
DMA_RTADDR_SMT) {

Thanks for adding this, I do believe this is a good addition but I also think 
that we might
need "is_pasid_enabled()" as well. It checks if PASIDE bit in context entry is 
enabled or not.

I am thinking that even though DMAR might be using scalable root and context 
table, the entry
itself should have PASIDE bit set. Did I miss something here?

No matter the PASIDE bit set or not, IOMMU always uses the scalable mode
page table if scalable mode is enabled. If PASIDE is set, requests with
PASID will be handled. Otherwise, requests with PASID will be blocked
(but request without PASID will always be handled).

We are dumpling the page table of the IOMMU, so we only care about what
page table format it is using. Do I understand it right>

Best regards,
Baolu


And I also think a macro would be better so that it could reused elsewhere (if 
need be).

Regards,
Sai

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