Messages in this thread | | | From | Thomas Gleixner <> | Subject | RE: TDX #VE in SYSCALL gap (was: [RFD] x86: Curing the exception and syscall trainwreck in hardware) | Date | Tue, 25 Aug 2020 21:49:07 +0200 |
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On Tue, Aug 25 2020 at 17:35, Tony Luck wrote: >> > Or malicious hypervisor action, and that's a problem. >> > >> > Suppose the hypervisor remaps a GPA used in the SYSCALL gap (e.g. the >> > actual SYSCALL text or the first memory it accesses -- I don't have a >> > TDX spec so I don't know the details). > > Is it feasible to defend against a malicious (or buggy) hypervisor? > > Obviously, we can't leave holes that guests can exploit. But the hypervisor > can crash the system no matter how clever TDX is.
If it crashes and burns reliably then fine, but is that guaranteed?
I have serious doubts about that given the history and fragility of all of this and I really have zero interest in dealing with the fallout a year from now.
Thanks,
tglx
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