Re: [PATCH 0/2] iommu/amd: Use MAX buffer size when SNP is enabled on Family 0x19

Usama,

On 8/13/2026 6:48 PM, Usama Arif wrote:
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> 
> On Mon, 20 Apr 2026 08:42:02 +0000 Vasant Hegde <[email protected]> wrote:
> 
>> This series addresses CVE-2023-20585 [1] by increasing the AMD IOMMU
>> Event log and PPR log buffer sizes to the maximum supported value (512K)
>> on affected CPU families when SNP is enabled.
>>
>> Use MAX buffer size when SNP is enabled on Milan/Genoa. Impacted buffers:
>>   - Milan : Event log (PPR/GALog is not supported when SNP is enabled)
>>   - Genoa : Event and PPR log (GALog is not supported when SNP is enabled)
>>
> 
> Hi,
> 
> This series seems to break kexec in our production on Milan hosts with SEV enabled.
> This is on the 6.18.43 stable kernel backport.

Do you have dmesg?

> 
> If on top of 6.18.43 release, we revert the 2 commits, i.e.
> Revert "iommu/amd: Use maximum PPR log buffer size when SNP is enabled on Family 0x19"
> Revert "iommu/amd: Use maximum Event log buffer size when SNP is enabled on Family 0x19"
> 
> kexec starts working again.
> > Could you help in fixing this issue?

Sure. We will try to reproduce it internally and get back to you.

-Vasant