On 5/12/20 11:39 AM, Jim Mattson wrote:
> On Mon, May 11, 2020 at 4:33 PM Babu Moger <[email protected]> wrote:
>>
>> MPK feature is supported by both VMX and SVM. So we can
>> safely move pkru state save/restore to common code. Also
>> move all the pkru data structure to kvm_vcpu_arch.
>>
>> Also fixes the problem Jim Mattson pointed and suggested below.
>>
>> "Though rdpkru and wrpkru are contingent upon CR4.PKE, the PKRU
>> resource isn't. It can be read with XSAVE and written with XRSTOR.
>> So, if we don't set the guest PKRU value here(kvm_load_guest_xsave_state),
>> the guest can read the host value.
>>
>> In case of kvm_load_host_xsave_state, guest with CR4.PKE clear could
>> potentially use XRSTOR to change the host PKRU value"
>>
>> Signed-off-by: Babu Moger <[email protected]>
>
> I would do the bugfix as a separate commit, to ease backporting it to
> the stable branches.
Ok. Sure.
