Re: [PATCH v6 06/11] x86/traps: Add #VE support for TDX guest
From: Joerg Roedel
Date: Tue Sep 28 2021 - 11:23:15 EST
On Tue, Sep 28, 2021 at 07:05:40AM -0700, Dave Hansen wrote:
> "Shared" pages can cause #VE's. The guest must be careful not to touch
> them in the syscall entry path, for example. But, shared pages are
> untrusted so they're not use for stacks.
> "Private" pages can cause #VE's. But, only *some* of them. Before a
> page is accepted, it is in the SEPT_PENDING and a reference would cause
> a #VE. But, after acceptance, page references either succeed or a TD
> Exit and the hypervisor gets to handle the situation.
Okay, and there is no way for the VMM to replace an already accepted
page with a page in SEPT_PENDING state?