Re: [PATCH v12 00/10] Introduce support for guest CET feature

From: Yang Weijiang
Date: Wed Jun 24 2020 - 01:56:11 EST


On Tue, Jun 23, 2020 at 11:39:19AM -0700, Sean Christopherson wrote:
> On Thu, Jun 11, 2020 at 09:29:13AM +0800, Yang Weijiang wrote:
> > On Wed, Jun 10, 2020 at 09:56:36AM -0700, Sean Christopherson wrote:
> > > On Wed, May 06, 2020 at 04:20:59PM +0800, Yang Weijiang wrote:
> > > > Several parts in KVM have been updated to provide VM CET support, including:
> > > > CPUID/XSAVES config, MSR pass-through, user space MSR access interface,
> > > > vmentry/vmexit config, nested VM etc. These patches have dependency on CET
> > > > kernel patches for xsaves support and CET definitions, e.g., MSR and related
> > > > feature flags.
> > >
> > > Other than the MSR and cpufeatures flags definitions, is there any direct
> > > dependency on kernel CET support? I.e. if/when XSAVES support is merged,
> > > is there anything beyond the architectural definitions that are required to
> > > merge KVM CET virtualization?
> > No, KVM CET patches only depend on kernel CET related definitions and XSAVES
> > support now.
>
> Neato.
>
> > But to make guest CET work, we need CET patches for QEMU.
>
> Ya, but we don't need to wait for host kernel support, which was the crux of
> my question.
>
>
> Can you please respin this series with the CET definition patches included?
> The XSAVES support has been queued to tip/x86/fpu. Assuming that lands in
> kernel 5.9, I _think_ KVM support for CET can land in 5.10.

Sure. Besides this change and the unrestricted guest case change, any
other changes I should do to v12 patch?

Thanks for review!
>
> Base your series on kvm/queue, i.e. don't worry about the XSAVES patches,
> I'll merge them in from tip/x86/fpu for testing.
>
> Thanks!