Messages in this thread | | | From | Andy Lutomirski <> | Date | Tue, 25 Aug 2020 10:41:46 -0700 | Subject | Re: TDX #VE in SYSCALL gap (was: [RFD] x86: Curing the exception and syscall trainwreck in hardware) |
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On Tue, Aug 25, 2020 at 10:36 AM Luck, Tony <tony.luck@intel.com> 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.
Crashing the system is one thing. Corrupting the system in a way that could allow code execution is another thing entirely. And the whole point of TDX is to defend the guest against the hypervisor.
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