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Date:   Thu, 4 Jun 2020 07:59:33 -0700
From:   Sean Christopherson <sean.j.christopherson@intel.com>
To:     Joerg Roedel <joro@8bytes.org>
Cc:     x86@kernel.org, hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Hellstrom <thellstrom@vmware.com>,
        Jiri Slaby <jslaby@suse.cz>,
        Dan Williams <dan.j.williams@intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Juergen Gross <jgross@suse.com>,
        Kees Cook <keescook@chromium.org>,
        David Rientjes <rientjes@google.com>,
        Cfir Cohen <cfir@google.com>,
        Erdem Aktas <erdemaktas@google.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Mike Stunes <mstunes@vmware.com>,
        Joerg Roedel <jroedel@suse.de>, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v3 25/75] x86/sev-es: Add support for handling IOIO
 exceptions
Message-ID: <20200604145932.GB30223@linux.intel.com>
References: <20200428151725.31091-1-joro@8bytes.org>
 <20200428151725.31091-26-joro@8bytes.org>
 <20200520062055.GA17090@linux.intel.com>
 <20200603142325.GB23071@8bytes.org>
 <20200603230716.GD25606@linux.intel.com>
 <20200604101502.GA20739@8bytes.org>
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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?