Re: [PATCH v9 09/17] x86/split_lock: Handle #AC exception for split lock

Paolo Bonzini
2019-10-21T13:03:17Z

On 16/10/19 19:42, Sean Christopherson wrote:
> KVM uses a locked cmpxchg in emulator_cmpxchg_emulated() and the address
> is guest controlled, e.g. a guest could coerce the host into disabling
> split-lock detection via the host's #AC handler by triggering emulation
> and inducing an #AC in the emulator.

Yes, that's a possible issue.

Paolo