linux-kernel - Re: [PATCH] KVM: VMX: Inject #UD if guest tries to execute SEAMCALL or TDCALL

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <68efc26c792a3_19928100a8@dwillia2-mobl4.notmuch>
Date: Wed, 15 Oct 2025 08:49:00 -0700
From: <dan.j.williams@...el.com>
To: Sean Christopherson <seanjc@...gle.com>, <dan.j.williams@...el.com>
CC: Paolo Bonzini <pbonzini@...hat.com>, <kvm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, Kai Huang <kai.huang@...el.com>, Xiaoyao Li
	<xiaoyao.li@...el.com>, Rick Edgecombe <rick.p.edgecombe@...el.com>
Subject: Re: [PATCH] KVM: VMX: Inject #UD if guest tries to execute SEAMCALL
 or TDCALL

Sean Christopherson wrote:
[..]
> IMO, any reasonable reading of "inSEAM" is that it is talking about #1, in which
> case the pseudocode effectively says that SEAMCALL should #UD if executed in
> "SEAM VMX non-root operation", but that's obviously not the case based on the
> statement below as well as the TDX-Module code.
> 
> Furthermore, the only transitions for"inSEAM" are that it's set to '1' by SEAMCALL,
> and cleared to '0' by SEAMRET.  That implies that it's _not_ cleared by VM-Enter
> from SEAM VMX root operation to SEAM VMX non-root operation, which reinforces my
> reading of "inSEAM == SEAM operation".

Ah, got it, I see it now. Added this need for clarification to the
errata ticket, and already got an ack on your Note2.