RE: [External] Re: [PATCH] Revert "iommu/amd: Treat per-device exclusion ranges as r/w unity-mapped regions"

[Adrian Huang12]

Hi Baoquan,

> -----Original Message-----
> From: Baoquan He <bhe@xxxxxxxxxx>
> Sent: Wednesday, September 23, 2020 10:33 AM
> To: joro@xxxxxxxxxx; Adrian Huang12 <ahuang12@xxxxxxxxxx>
> Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> jsnitsel@xxxxxxxxxx
> Subject: [External] Re: [PATCH] Revert "iommu/amd: Treat per-device exclusion
> ranges as r/w unity-mapped regions"
> 
> Forgot CC-ing Jerry, add him.
> 
> On 09/23/20 at 10:26am, Baoquan He wrote:
> > A regression failure of kdump kernel boot was reported on a HPE system.
> > Bisect points at commit 387caf0b759ac43 ("iommu/amd: Treat per-device
> > exclusion ranges as r/w unity-mapped regions") as criminal. Reverting
> > it fix the failure.
> >
> > With the commit, kdump kernel will always print below error message,
> > then naturally AMD iommu can't function normally during kdump kernel
> bootup.
> >
> >   ~~~~~~~~~
> >   AMD-Vi: [Firmware Bug]: IVRS invalid checksum
> >
> > Why commit 387caf0b759ac43 causing it haven't been made clear.
> 
> Hi Joerg, Adrian
> 
> We only have one machine which can reproduce the issue, it's a gen10-01 of
> HPE. If any log or info are needed, please let me know, I can attach here.

Could you please provide the following info?
1. The booting log for both system kernel and kdump kernel by appending the kernel parameter 'amd_iommu_dump'
2. ACPI table (# acpidump > acpi-table) -> Send out the file 'acpi-table'. 

-- Adrian