在 2018/1/19 15:57, Christian Borntraeger 写道:
On 01/19/2018 07:29 AM, QingFeng Hao wrote:
在 2018/1/17 17:48, Martin Schwidefsky 写道:
Clear all user space registers on entry to the kernel and all KVM guest
registers on KVM guest exit if the register does not contain either a
parameter or a result value.
I am not sure if I understand this but it will be safer?
It ist similar to commit 0cb5b30698fd ("kvm: vmx: Scrub hardware GPRs at VM-exit").
The idea is to minimize potential payload channels.
Got it! thanks for your explanation!
And can we abstract the operations to be a macro like CLEAR_REG_7?
No, please.
xgr %r7,%r7
is absolutely clear what it does, a MACRO often is not.
nod, this makes sense!
--
Regards
QingFeng Hao