Interrupt Security for AMD SEV-SNP
summary
AMD SEV‑SNP adds restricted interrupt injection and an alternate injection mode: restricted replaces VM interrupt queuing with a single benign VMCB vector (vector 28) and a shared HP doorbell page (pending-event and EOI bits) that the host sets. Kernel paths that enable interrupts must check the doorbell and atomically consume pending vectors; KVM and OVMF patches implement restricted mode now, nested HP‑stack overflow currently triggers a panic, RFCs are planned.
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chapters (11)
- 0:00Introduction to interrupt security
- 1:05Why interrupt protection is needed
- 3:31Restricted interrupt injection explained
- 9:46Interrupt injection flow on KVM host
- 15:19Host side interrupt callbacks
- 23:07Guest side interrupt handling
- 26:58Nested HP exception handling
- 30:50Handling halt and interrupts
- 33:00Optimizing system vector handling
- 35:59Alternate interrupt injection mode
- 37:24Q&A and conclusion
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