4 ms·

Triple fault? It seems that double fault exception (abort) should be triggered first.

• userbinator 11y ago
  I believe the phrase "it is architecturally specified that these would be delivered sequentially" means that #DF doesn't always occur, depending on what the two exception types were; this goes back to the 80386: http://intel80386.com/386htm/s09_08.htm http://intel80386.com/386htm/s09_08.htm That has always been there, but I guess the wording is a bit unclear/the edge case where a "benign exception" occurs while handling another one was never really considered. If I had time I'd try these scenarios on real hardware to see if double or triple-fault happens, or if the CPU does get stuck in a loop. The real problem might not be this edge-case itself, if real hardware can also get into an infinite loop (after all, some process running in a VM can easily execute one of those); it's the fact that the host loses control of the virtualised CPU.
  • yuhong 11y ago
    Yep, I think they said the problem is the CPU hanging in a infinite loop in microcode with not even SMIs being delivered.