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

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

in my patch kit.

-Andi