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;
MIME-Version: 1.0
References: <20211005234459.430873-1-michael.roth@amd.com> <20211006203710.13326-1-michael.roth@amd.com>
 <CAA03e5EmnbpKOwfNJUV7fog-7UpJJNpu7mQYmCODpk=tYfXxig@mail.gmail.com> <20211012011537.q7dwebcistxddyyj@amd.com>
In-Reply-To: <20211012011537.q7dwebcistxddyyj@amd.com>
From:   Mingwei Zhang <mizhang@google.com>
Date:   Wed, 3 Nov 2021 22:25:02 -0700
Message-ID: <CAL715WKBBXNpJFK-3254ox_GU=v04RdYC=uXu4S5kbf=1R9aYA@mail.gmail.com>
Subject: Re: [RFC 06/16] KVM: selftests: add library for creating/interacting
 with SEV guests
To:     Michael Roth <Michael.Roth@amd.com>
Cc:     Marc Orr <marcorr@google.com>, linux-kselftest@vger.kernel.org,
        kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>,
        Nathan Tempelman <natet@google.com>,
        Steve Rutherford <srutherford@google.com>,
        Sean Christopherson <seanjc@google.com>,
        Brijesh Singh <brijesh.singh@amd.com>,
        Tom Lendacky <Thomas.Lendacky@amd.com>,
        Varad Gautam <varad.gautam@suse.com>,
        Shuah Khan <shuah@kernel.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Ricardo Koller <ricarkol@google.com>,
        Jim Mattson <jmattson@google.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Joerg Roedel <joro@8bytes.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

>
> >
> > > +#define SEV_FW_REQ_VER_MAJOR   1
> > > +#define SEV_FW_REQ_VER_MINOR   30
> >
> > Where does the requirement for this minimum version come from? Maybe
> > add a comment?
> >
> > Edit: Is this for patches later on in the series that exercise SNP? If
> > so, I think it would be better to add a check like this in the test
> > itself, rather than globally. I happened to test this on a machine
> > with a very old PSP FW, 0.22, and the SEV test added in patch #7 seems
> > to work fine with this ancient PSP FW.
>
> Ah, yes, this was mostly for SNP support. I'll implement a separate minimum
> version for SEV/SEV-ES.
>

I want to ask the same thing, I tried to run the sev selftest today
and I was blocked by this minimum version number... BTW: I suspect if
I want to update the SEV firmware I have to update the BIOS myself?
So, it would be good to know what is the actual minimum for SEV.

In addition, maybe that's side effect, I see a warning when building the kernel:

"module ccp.ko requires firmware amd/amd_sev_fam19h_model0xh.sbin"

Maybe I need some hints from you? Or maybe it is just harmless. I did
double checked and it looks like I was using either
amd_sev_fam17h_model3xh.sbin or amd_sev_fam17h_model0xh.sbin

Thanks.
-Mingwei