Re: [patch V6 05/14] MDS basics 5

On Thu, 7 Mar 2019, speck for Andi Kleen wrote:
> On Fri, Mar 01, 2019 at 10:47:43PM +0100, speck for Thomas Gleixner wrote:
> > From: Andi Kleen <[email protected]>
> > Subject: [patch V6 05/14] x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests
> > 
> > X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode
> > provides the mechanism to invoke a flush of various exploitable CPU buffers
> > by invoking the VERW instruction.
> > 
> > Hand it through to guests so they can adjust their mitigations.
> > 
> > This also requires corresponding qemu changes, which are available
> > separately.
> 
> This patch is not complete. You also need some variant of 
> 
> x86/speculation/mds: Handle VMENTRY clear for CPUs without l1tf

650b68a0622f ("x86/kvm/vmx: Add MDS protection when L1D Flush is not active")

Thanks,

	tglx