Re: [PATCH 0/2] iommu/amd: Use MAX buffer size when SNP is enabled on Family 0x19
Usama Arif <[email protected]>
| Newsgroups | dev.linux.lists.iommu |
|---|---|
| Message-ID | <[email protected]> |
On 13/08/2026 14:58, Vasant Hegde wrote: > Usama, > > On 8/13/2026 6:48 PM, Usama Arif wrote: >> [You don't often get email from [email protected]. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] >> >> 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? > We don't get any logs after kexec. So the last logs are: [ OK ] Reached target shutdown.target - System Shutdown. [ OK ] Reached target final.target - Late Shutdown Services. [ OK ] Finished systemd-kexec.service - Reboot via kexec. [ OK ] Reached target kexec.target - Reboot via kexec. And then nothing after. >> >> 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. > Thanks! > -Vasant >