Re: [PATCH 1/2] iommu/vt-d: Fix checks in dmar_fault_dump_ptes()

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2024/10/23 13:09, Duan, Zhenzhong wrote:
>>> ---
>>>    drivers/iommu/intel/iommu.c | 31 ++++++++++++++++++++-----------
>>>    1 file changed, 20 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>>> index a564eeaf2375..8288b0ee7a61 100644
>>> --- a/drivers/iommu/intel/iommu.c
>>> +++ b/drivers/iommu/intel/iommu.c
>>> @@ -733,12 +733,17 @@ void dmar_fault_dump_ptes(struct intel_iommu
>> *iommu, u16 source_id,
>>>    	u8 devfn = source_id & 0xff;
>>>    	u8 bus = source_id >> 8;
>>>    	struct dma_pte *pgtable;
>>> +	u64 entry;
>>>
>>>    	pr_info("Dump %s table entries for IOVA 0x%llx\n", iommu->name, addr);
>>>
>>>    	/* root entry dump */
>>>    	rt_entry = &iommu->root_entry[bus];
>>> -	if (!rt_entry) {
>>> +	entry = rt_entry->lo;
>>> +	if (sm_supported(iommu) && devfn >= 0x80)
>>> +		entry = rt_entry->hi;
>>> +
>>> +	if (!(entry & 1)) {
>>>    		pr_info("root table entry is not present\n");
>>>    		return;
>>>    	}
>>> @@ -766,28 +771,32 @@ void dmar_fault_dump_ptes(struct intel_iommu
>> *iommu, u16 source_id,
>>>    		goto pgtable_walk;
>>>    	}
>>>
>>> +	/* For request-without-pasid, get the pasid from context entry */
>>> +	if (pasid == IOMMU_PASID_INVALID)
>>> +		pasid = IOMMU_NO_PASID;
>>> +
>>>    	/* get the pointer to pasid directory entry */
>>>    	dir = phys_to_virt(ctx_entry->lo & VTD_PAGE_MASK);
>> Is above code correct in the scalable mode?
> I didn't find issue, could you show some light?

It's fine. I just mixed it with the root entry.

Thanks,
baolu