From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sean Christopherson <sean.j.christopherson@intel.com>
Subject: Re: [PATCH v3 25/75] x86/sev-es: Add support for handling IOIO
 exceptions
Date: Thu, 4 Jun 2020 07:59:33 -0700
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To: Joerg Roedel <joro@8bytes.org>
Cc: Juergen Gross <jgross@suse.com>, Tom Lendacky <thomas.lendacky@amd.com>, Thomas Hellstrom <thellstrom@vmware.com>, Dave Hansen <dave.hansen@linux.intel.com>, Mike Stunes <mstunes@vmware.com>, Kees Cook <keescook@chromium.org>, kvm@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>, Cfir Cohen <cfir@google.com>, x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Joerg Roedel <jroedel@suse.de>, Masami Hiramatsu <mhiramat@kernel.org>, Andy Lutomirski <luto@kernel.org>, hpa@zytor.com, Erdem Aktas <erdemaktas@google.com>, David Rientjes <rientjes@google.com>, Dan Williams <dan.j.williams@intel.com>, Jiri Slaby <jslaby@suse.cz>
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On Thu, Jun 04, 2020 at 12:15:02PM +0200, Joerg Roedel wrote:
> On Wed, Jun 03, 2020 at 04:07:16PM -0700, Sean Christopherson wrote:
> > On Wed, Jun 03, 2020 at 04:23:25PM +0200, Joerg Roedel wrote:
> > > User-space can also cause IOIO #VC exceptions, and user-space can be
> > > 32-bit legacy code with segments, so es_base has to be taken into
> > > account.
> > 
> > Is there actually a use case for this?  Exposing port IO to userspace
> > doesn't exactly improve security.
> 
> Might be true, but Linux supports it and this patch-set is not the place
> to challenge this feature.

But SEV already broke it, no?