lkml.org 
[lkml]   [2020]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC PATCH 25/35] KVM: x86: Update __get_sregs() / __set_sregs() to support SEV-ES
Date
On 16/09/20 00:44, Sean Christopherson wrote:
>> KVM doesn't have control of them. They are part of the guest's encrypted
>> state and that is what the guest uses. KVM can't alter the value that the
>> guest is using for them once the VMSA is encrypted. However, KVM makes
>> some decisions based on the values it thinks it knows. For example, early
>> on I remember the async PF support failing because the CR0 that KVM
>> thought the guest had didn't have the PE bit set, even though the guest
>> was in protected mode. So KVM didn't include the error code in the
>> exception it injected (is_protmode() was false) and things failed. Without
>> syncing these values after live migration, things also fail (probably for
>> the same reason). So the idea is to just keep KVM apprised of the values
>> that the guest has.
>
> Ah, gotcha. Migrating tracked state through the VMSA would probably be ideal.
> The semantics of __set_sregs() kinda setting state but not reaaaally setting
> state would be weird.

How would that work with TDX?

Paolo

\
 
 \ /
  Last update: 2020-11-30 19:33    [W:0.120 / U:0.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site