Re: [REGRESSION] [6.12.y] crypto: ccp - Move SEV/SNP Platform initialization to KVM breaks SEV-ES VM launch

[Sean Christopherson <seanjc@google.com>]

On Wed, Sep 02, 2026, Andrew Wilson wrote:
> #regzbot introduced: 3f8f0133a5fc9b32d0c308530320c3f2430ba5ab
> 
> Hi all,
> 
> I am writing to report a regression affecting AMD SEV-ES VM launches
> on the 6.12 stable branch (first noticed in 6.12.97+ / 6.12.101).
> 
> I completed a git bisect between working and failing kernels, which pointed to:
> 
> Commit: bb1c84647025 ("crypto: ccp - Move SEV/SNP Platform
> initialization to KVM")
> Upstream commit: 3f8f0133a5fc9b32d0c308530320c3f2430ba5ab
> 
> ### Bisect & Verification Details:
> * Last Known Working: 8a599f4f74d4
> * First Broken Commit: bb1c84647025
> * Tested on 6.12.101: Cleanly reverting bb1c84647025 immediately
> resolves the issue and allows SEV-ES guests to boot normally.

Can you try v6.12.104 or later?  I'm pretty sure this is fixed by commit
6b748c39d18e ("KVM: SVM: Add support to initialize SEV/SNP functionality in KVM"),
i.e. is the same thing as:
https://lore.kernel.org/all/20260814100652.225499-1-jinpu.wang@ionos.com

Note, SNP is still buggered on 6.12.y if CONFIG_KVM_AMD=y, I'll try and send a
backport for that soonish.
https://lore.kernel.org/all/521b22fa-ef09-4449-909f-0120edfc4b24@oracle.com

> ### Failure Description:
> With commit bb1c84647025 applied, `sev_platform_init(&args)` is
> removed from `sev_pci_init()`, assuming KVM handles on-demand
> initialization.
> 
> On bare metal, the PSP firmware appears to remain uninitialized (does
> not reach SEV_STATE_INIT at probe time). When QEMU initializes KVM and
> queries host SEV-ES capabilities, the ioctl fails with -EPERM:
> 
>   qemu-system-x86_64: -accel kvm: sev_common_kvm_init: guest policy
> requires SEV-ES, but host SEV-ES support unavailable
>   qemu-system-x86_64: -accel kvm: failed to initialize kvm: Operation
> not permitted
> 
> ### Hardware & Environment:
> * Tested on: AMD EPYC (Rome / Milan) Supermicro platforms
> * Kernel: Linux 6.12.101
> * Hypervisor: QEMU / KVM
> 
> I have access to Naples, Rome, and Milan test hardware and am happy to
> test any patches, provide dmesg traces, or assist with debugging.  I
> am not a tech-expert of any kind, but I have time to do some testing
> if it helps.  THANK YOU for the great work.
> 
> Original Debian bug reference:
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1145026