Re: [PATCH] x86/cpu: Add a VMX flag to enumerate 5-level EPT support to userspace

Sean Christopherson
2024-01-10T13:59:25Z

On Wed, Jan 10, 2024, Tao Su wrote:
> On Tue, Jan 09, 2024 at 04:23:40PM -0800, Sean Christopherson wrote:
> > Add a VMX flag in /proc/cpuinfo, ept_5level, so that userspace can query
> > whether or not the CPU supports 5-level EPT paging. EPT capabilities are
> > enumerated via MSR, i.e. aren't accessible to userspace without help from
> > the kernel, and knowing whether or not 5-level EPT is supported is sadly
> > necessary for userspace to correctly configure KVM VMs.
> >
> > When EPT is enabled, bits 51:49 of guest physical addresses are consumed
>
> nit: s/49/48

Argh, you even pointed that out before too. Thanks!