Re: [PATCH v10 10/16] KVM: x86: Introduce KVM_GET_SHARED_PAGES_LIST ioctl

[Sean Christopherson]

On Thu, Feb 04, 2021, Ashish Kalra wrote:
> From: Brijesh Singh <brijesh.singh@xxxxxxx>
> 
> The ioctl is used to retrieve a guest's shared pages list.

What's the performance hit to boot time if KVM_HC_PAGE_ENC_STATUS is passed
through to userspace?  That way, userspace could manage the set of pages in
whatever data structure they want, and these get/set ioctls go away.

Also, aren't there plans for an in-guest migration helper?  If so, do we have
any idea what that interface will look like?  E.g. if we're going to end up with
a full fledged driver in the guest, why not bite the bullet now and bypass KVM
entirely?