From: "Min Xu" <min.m.xu@intel.com>
To: "devel@edk2.groups.io" <devel@edk2.groups.io>,
"lersek@redhat.com" <lersek@redhat.com>,
"Yao, Jiewen" <jiewen.yao@intel.com>,
"rfc@edk2.groups.io" <rfc@edk2.groups.io>
Cc: "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
"erdemaktas@google.com" <erdemaktas@google.com>,
"cho@microsoft.com" <cho@microsoft.com>,
"bret.barkelew@microsoft.com" <bret.barkelew@microsoft.com>,
Jon Lange <jlange@microsoft.com>, Karen Noel <knoel@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Nathaniel McCallum <npmccallum@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Ademar de Souza Reis Jr. <areis@redhat.com>
Subject: Re: [edk2-rfc] [edk2-devel] RFC: design review for TDVF in OVMF
Date: Wed, 23 Jun 2021 11:56:09 +0000 [thread overview]
Message-ID: <PH0PR11MB50647245A457486875900FEEC5089@PH0PR11MB5064.namprd11.prod.outlook.com> (raw)
In-Reply-To: <4d0fc023-6520-43f6-0b0e-9db7bf15a85c@redhat.com>
On 06/22/2021 9:35 PM, Laszlo wrote:
> Hi,
>
> On 06/11/21 08:37, Xu, Min M wrote:
> > In today's TianoCore Design Meeting we reviewed the Overview Section
> (from slide 1 to 20). Thanks much for the valuable feedbacks and comments.
> The meeting minutes will be sent out soon.
> >
> > To address the concerns of the *one binary* solution in previous
> > discussion, we propose 2 Configurations for TDVF to upstream. (slide 6
> > - 8)
> >
> >
> >
> > Config-A:
> >
> > * Merge the *basic* TDVF feature to existing OvmfX64Pkg.dsc. (Align
> with existing SEV)
> > * Threat model: VMM is NOT out of TCB. (We don't make things worse.)
> > * The OvmfX64Pkg.dsc includes SEV/TDX/normal OVMF basic boot
> capability. The final binary can run on SEV/TDX/normal OVMF
> > * No changes to existing OvmfPkgX64 image layout.
> > * No need to add additional security features if they do not exist today
> > * No need to remove features if they exist today.
> > * RTMR is not supported
> > * PEI phase is NOT skipped in either Td or Non-Td
>
> (so this is "Config-A / Option B", per slide 9 in the v0.9 slide deck)
>
Yes, in Config-A we chose to follow the standard EDK2 flow (SEC -> PEI -> DXE -> BDS)
So that the changes in Config-A is not too intrusive.
>
>
> >
> >
> >
> > Config-B:
> >
> > * Add a standalone IntelTdx.dsc to a TDX specific directory for a *full*
> feature TDVF. (Align with existing SEV)
> > * Threat model: VMM is out of TCB. (We need necessary change to
> prevent attack from VMM)
> > * IntelTdx.dsc includes TDX/normal OVMF basic boot capability. The final
> binary can run on TDX/normal OVMF
> > * It might eventually merge with AmdSev.dsc, but NOT at this point of
> time. And we don't know when it will happen. We need sync with AMD in
> the community, after both of us think the solutions are mature to merge.
> > * Need to add necessary security feature as mandatory requirement,
> such as RTMR based Trusted Boot support
> > * Need to remove unnecessary attack surfaces, such as network stack.
>
> After reading the above, and checking slides 6 through 10 of the v0.9 slide
> deck:
>
> - I prefer Config-B (IntelTdx.dsc).
>
> This is in accordance with what I wrote earlier about "OvmfPkgX64.dsc"
> maintainability and regressions.
>
> Additionally (given that a full-featured TDVF is the ultimate goal), I see the
> advance from "Config-A / option B" to "Config-B" a lot less
> *incremental* than the step from "OvmfPkgX64.dsc" to "AmdSev.dsc" was.
>
> Put differently, I think that any TDX work targeted at "OvmfPkgX64.dsc"
> is going to prove less useful for the final "IntelTdx.dsc" than how reusable
> SEV work from "OvmfPkgX64.dsc" did for "AmdSev.dsc".
>
> Put yet differently, I'm concerned that a part of the TDX work for
> "OvmfPkgX64.dsc" might be a waste, with an eye towards the ultimate TDVF
> feature set ("IntelTdx.dsc").
>
Actually Config-A and Config-B share some common (or basic) TDX features,
for example, the ResetVector, Memory Accept in SEC phase, IoMMU/DMA in
DXE phase, and the base IoLib, etc.
Config-A supports the basic Tdx features (except the security features).
Config-B supports the full set of Tdx features.
>
>
> - I could (very cautiously) live with "Config-A / option B" as the initial
> approach. However, we'de have to be ready to make the full split (the
> switch-over to "IntelTdx.dsc") at *any point* during development, in case
> something turns out to be too intrusive. (And yes, "too intrusive" is
> subjective.)
>
Yes, we will always keep in mind the maintainability and regressions about
"OvmfPkgX64.dsc". So as the initial approach, only the basic Tdx features will
be included in Config-A.
>
> By this I mean that any particular patch towards "Config-A / option B"
> could cause me to ask, "please create IntelTdx.dsc now". Note that the later
> we make the switch the more painful it could be (= the more invested in
> "OvmfPkgX64.dsc" we could be, at that point).
>
Yes we will submit the patch for Config-B when any particular patch towards
"Config-A", so that we will not have a big surprise in the future.
>
Thanks!
Min
prev parent reply other threads:[~2021-06-23 11:56 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 13:51 [edk2-rfc] [edk2-devel] RFC: design review for TDVF in OVMF Yao, Jiewen
2021-06-03 16:11 ` Laszlo Ersek
2021-06-03 23:19 ` Yao, Jiewen
2021-06-04 10:11 ` Laszlo Ersek
2021-06-04 10:24 ` Yao, Jiewen
2021-06-04 10:43 ` Michael Brown
2021-06-04 14:52 ` Michael Brown
2021-06-04 15:04 ` James Bottomley
2021-06-04 7:33 ` Min Xu
2021-06-06 2:03 ` Min Xu
2021-06-06 11:29 ` Michael Brown
2021-06-06 12:49 ` Min Xu
2021-06-07 13:52 ` Laszlo Ersek
2021-06-06 8:52 ` Min Xu
2021-06-06 11:39 ` Michael Brown
2021-06-08 12:27 ` Min Xu
2021-06-08 15:36 ` Laszlo Ersek
2021-06-08 16:01 ` James Bottomley
2021-06-08 19:33 ` Laszlo Ersek
2021-06-09 0:58 ` Min Xu
2021-06-09 11:00 ` Laszlo Ersek
2021-06-09 14:36 ` James Bottomley
2021-06-09 2:01 ` Min Xu
2021-06-09 14:28 ` James Bottomley
2021-06-09 15:47 ` Paolo Bonzini
2021-06-09 15:59 ` James Bottomley
2021-06-10 21:01 ` Erdem Aktas
2021-06-10 22:30 ` Min Xu
2021-06-11 1:33 ` James Bottomley
2021-06-11 1:36 ` Yao, Jiewen
2021-06-11 1:38 ` James Bottomley
2021-06-11 1:55 ` James Bottomley
[not found] ` <168759329436FBCF.5845@groups.io>
2021-06-11 6:37 ` Min Xu
2021-06-22 13:34 ` Laszlo Ersek
2021-06-22 13:38 ` Laszlo Ersek
2021-06-24 0:24 ` Min Xu
2021-06-24 0:35 ` James Bottomley
2021-06-24 0:55 ` Min Xu
[not found] ` <168B5EA81BA66FAC.7570@groups.io>
2021-07-01 5:00 ` Min Xu
2021-06-23 2:44 ` Min Xu
2021-06-23 17:47 ` Laszlo Ersek
2021-06-23 11:56 ` Min Xu [this message]
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