Debug Exception Delivery in Secure Nested Paging

Bulletin ID:    AMD-SB-3006
Potential Impact: Suppression of guest debug exceptions
Severity: Low

Summary

A researcher has reported that a host can potentially suppress delivery of debug exceptions to SEV-SNP guests that have the restricted injection feature enabled. For example, a software-based debugger generating hardware-based exceptions for the purpose of debugging may not see the exceptions delivered to the VM guest. In particular, hardware debug traps such as single-stepping and data breakpoints may not be observed in the guest.

CVE Details

Refer to Glossary for explanation of terms

Affected Products

3rd Gen AMD EPYC™ processors

4th Gen AMD EPYC™ processors

Mitigation

No mitigation is planned for this issue. SEV-SNP guest that have the alternate injection feature enabled are not affected.

Acknowledgement

AMD thanks Tom Dohrmann for reporting this issue and engaging in coordinated vulnerability disclosure.

Revisions 

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