Re: [PATCH] KVM: X86: Fix the decoding of segment overrides in 64bit mode

From: Wanpeng Li
Date: Thu Mar 22 2018 - 09:39:57 EST


2018-03-22 20:38 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
> On 22/03/2018 12:04, Andrew Cooper wrote:
>> We've got a Force Emulation Prefix (ud2a; .ascii "xen") for doing
>> magic. Originally, this was used for PV guests to explicitly request an
>> emulated CPUID, but I extended it to HVM guests for "emulate the next
>> instruction", after we had some guest user => guest kernel privilege
>> escalations because of incorrect emulation.
>
> Wanpeng, why don't you add it behind a new kvm module parameter? :)

Great point! I will have a try. Thanks Paolo and Andrew. :)

Regards,
Wanpeng Li