Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 11 Jan 2021 10:55:49 -0800 (PST)
From:   David Rientjes <rientjes@google.com>
To:     Tom Lendacky <thomas.lendacky@amd.com>
cc:     "Hyunwook (Wooky) Baek" <baekhw@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Joerg Roedel <jroedel@suse.de>,
        Sean Christopherson <seanjc@google.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH V2] x86/sev-es: Fix SEV-ES #VC handler for string port
 IO
In-Reply-To: <1c7f7df6-11f0-e290-cb26-6d8c01b45e2c@amd.com>
Message-ID: <4f71f9a4-3d78-a876-6fab-25549756fd2e@google.com>
References: <20210110071102.2576186-1-baekhw@google.com> <1c7f7df6-11f0-e290-cb26-6d8c01b45e2c@amd.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Mon, 11 Jan 2021, Tom Lendacky wrote:

> > Don't assume dest/source buffers are userspace addresses when manually
> > copying data for string I/O or MOVS MMIO, as {get,put}_user() will fail
> > if handed a kernel address and ultimately lead to a kernel panic.
> > 
> > Signed-off-by: Hyunwook (Wooky) Baek <baekhw@google.com>
> > Acked-by: David Rientjes <rientjes@google.com>
> > ---
> > 
> > This patch is tested by invoking INSB/OUTSB instructions in kernel space in
> > a
> > SEV-ES-enabled VM. Without the patch, the kernel crashed with the following
> > message:
> >    "SEV-ES: Unsupported exception in #VC instruction emulation - can't
> > continue"
> > With the patch, the instructions successfully read/wrote the string from/to
> > the I/O port.
> 
> Shouldn't this have a Fixes: tag?
> 

Makes sense, I think this should likely be:

Fixes: f980f9c31a92 ("x86/sev-es: Compile early handler code into kernel image")