Re: [PATCH v7 4/7] KVM: VMX: Load Guest CET via VMCS when CET is enabled in Guest

From: Jim Mattson
Date: Wed Oct 09 2019 - 19:09:06 EST


On Tue, Oct 8, 2019 at 11:41 PM Yang Weijiang <weijiang.yang@xxxxxxxxx> wrote:
>
> On Wed, Oct 02, 2019 at 11:54:26AM -0700, Jim Mattson wrote:
> > On Thu, Sep 26, 2019 at 7:17 PM Yang Weijiang <weijiang.yang@xxxxxxxxx> wrote:
> > > + if (cet_on)
> > > + vmcs_set_bits(VM_ENTRY_CONTROLS,
> > > + VM_ENTRY_LOAD_GUEST_CET_STATE);
> >
> > Have we ensured that this VM-entry control is supported on the platform?
> >
> If all the checks pass, is it enought to ensure the control bit supported?

I don't think so. The only way to check to see if a VM-entry control
is supported is to check the relevant VMX capability MSR.

BTW, what about the corresponding VM-exit control?