Re: [PATCH 2/5] KVM: nVMX: Verify the VMX controls MSRs with the global capability when setting VMX MSRs

Chenyi Qiang
2020-08-31T03:16:23Z

On 8/29/2020 2:23 AM, Jim Mattson wrote:
> On Fri, Aug 28, 2020 at 1:54 AM Chenyi Qiang <chenyi.qiang@intel.com> wrote:
>>
>> When setting the nested VMX MSRs, verify it with the values in
>> vmcs_config.nested_vmx_msrs, which reflects the global capability of
>> VMX controls MSRs.
>>
>> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
>
> You seem to have entirely missed the point of this code, which is to
> prevent userspace from adding features that have previously been
> removed for this vCPU (e.g as a side-effect of KVM_SET_CPUID).
>

We only have the case that the scope of features set by userspace is
always reduced, right? If so, we don't need the change here.