There is no /dev/sev file

[dddjjjiie]

When sev is enabled in BIOS, there is no /dev/sev file. Can I solve this problem by installing a new kernel according to the documentation?
The specific configuration is as follows: amd epyc 9575F, ubuntu22, Linux ubuntu 5.15.0-136-generic

[aik]

Please attach the lscpu output. /dev/sev is created by the ccp module (not kvm_amd) and should be present since ccp is loaded.

[dddjjjiie]

Please attach the lscpu output. /dev/sev is created by the ccp module (not kvm_amd) and should be present since ccp is loaded.

[Vap0RSh4wN]

[tlendacky]

Please supply the output of: dmesg | grep -E "ccp|SEV"

[dddjjjiie]

Please supply the output of: dmesg | grep -E "ccp|SEV"

No output

[tlendacky]

Looks like the stock kernel doesn't recognize the ASP device ID. A 9575F is Zen 5 processor. The device ID for that was added in v6.5 of the Linux kernel. You'll need to move up at least that level. Depending on the level of Ubuntu you're running, it may have an hwe kernel that gets you there.

[dddjjjiie]

Looks like the stock kernel doesn't recognize the ASP device ID. A 9575F is Zen 5 processor. The device ID for that was added in v6.5 of the Linux kernel. You'll need to move up at least that level. Depending on the level of Ubuntu you're running, it may have an hwe kernel that gets you there.

Thank you for the detailed explanation — it's very helpful! I understand now that the issue is due to the current kernel not fully supporting the EPYC 9575F CPU, and that upgrading to at least Linux 6.5 should resolve the missing /dev/sev problem. I’ll proceed to upgrade the kernel and see if that fixes it. I’ll reach out again if I run into any issues. Thanks again!