Re: [PATCH v5 13/15] iommu/amd: Use the generic iommu page table

Jason Gunthorpe
2025-09-25T12:32:33Z

On Thu, Sep 25, 2025 at 12:07:04PM +0000, Ankit Soni wrote:
> > +
> > + cfg.common.hw_max_vasz_lg2 =
> > + max(64, (amd_iommu_hpt_level - 1) * 9 + 21);

> s/max/min
> with 6 level page table max will be 66 and i am seeing boot failure with
> this. Please refer below fail log.

Oops, I added this when rebasing, thanks. Just to be clear the max/min
fixes the oops?

> [ 5.458439] BUG: kernel NULL pointer dereference, address: 0000000000000030
> [ 5.459338] #PF: supervisor read access in kernel mode
> [ 5.459338] #PF: error_code(0x0000) - not-present page
> [ 5.459338] PGD 0
> [ 5.459338] Oops: Oops: 0000 [#1] SMP NOPTI
> [ 5.459338] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-rc3+ #83 PREEMPT(voluntary)
> [ 5.459338] Hardware name: AMD Corporation RUBY/RUBY, BIOS RRR100DB 08/09/2024
> [ 5.459338] RIP: 0010:sysfs_add_link_to_group+0x16/0x60

Really weird the above triggers oops here???

I updated the github

Thanks!
Jason