Hi Wolfgang,
On 5/15/21 9:28 PM, Wolfgang Müller wrote:
Hi!
First of all, apologies if this is the wrong place to post a problem report. I figured since I was going to reference a particular commit anyway I might as well reply to the patch series that (seemed to have) introduced the problem.
From: Lu Baolu baolu.lu@linux.intel.com
[ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]
The Access/Dirty bits in the first level page table entry will be set whenever a page table entry was used for address translation or write permission was successfully translated. This is always true when using the first-level page table for kernel IOVA. Instead of wasting hardware cycles to update the certain bits, it's better to set them up at the beginning.
This commit seems to trigger a kernel panic very early in boot for me in 5.10.37 (36 is fine):
It seems due to the back-ported patch:
- if (!sg) { - sg_res = nr_pages; - pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr; + if (domain->domain.type == IOMMU_DOMAIN_DMA) { + attr |= DMA_FL_PTE_ACCESS; + if (prot & DMA_PTE_WRITE) + attr |= DMA_FL_PTE_DIRTY; + } }
+ pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr;
Greg, do you want me to rework this patch, or submit an incremental fix?
Best regards, baolu