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

[Vasant Hegde <vasant.hegde@amd.com>]

Usama,


On 8/17/2026 9:36 PM, Usama Arif wrote:
> On Thu, 13 Aug 2026 19:28:55 +0530 Vasant Hegde <vasant.hegde@amd.com> wrote:
> 
>> Usama,
>>
>> On 8/13/2026 6:48 PM, Usama Arif wrote:
>>> [You don't often get email from usama.arif@linux.dev. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>>>
>>> On Mon, 20 Apr 2026 08:42:02 +0000 Vasant Hegde <vasant.hegde@amd.com> 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?

We downgrade the firmware version to match the version you reported and able to
reproduce this issue.  But this is the CVE fix and I'd recommend you to upgrade
the FW. With latest FW we don't see any issues.


-Vasant