[v1,0/3] TDX Guest Quote generation support

Message

Kuppuswamy Sathyanarayanan March 26, 2023, 6:20 a.m. UTC

Hi All,

In TDX guest, the attestation process is used to verify the TDX guest
trustworthiness to other entities before provisioning secrets to the
guest.

The TDX guest attestation process consists of two steps:

1. TDREPORT generation
2. Quote generation.

The First step (TDREPORT generation) involves getting the TDX guest
measurement data in the format of TDREPORT which is further used to
validate the authenticity of the TDX guest. The second step involves
sending the TDREPORT to a Quoting Enclave (QE) server to generate a
remotely verifiable Quote. TDREPORT by design can only be verified on
the local platform. To support remote verification of the TDREPORT,
TDX leverages Intel SGX Quoting Enclave to verify the TDREPORT
locally and convert it to a remotely verifiable Quote. Although
attestation software can use communication methods like TCP/IP or
vsock to send the TDREPORT to QE, not all platforms support these
communication models. So TDX GHCI specification [1] defines a method
for Quote generation via hypercalls. Please check the discussion from
Google [2] and Alibaba [3] which clarifies the need for hypercall based
Quote generation support. This patch set adds this support.

Support for TDREPORT generation already exists in the TDX guest driver. 
This patchset extends the same driver to add the Quote generation
support.

Following are the details of the patch set:

Patch 1/3 -> Adds event notification IRQ support.
Patch 2/3 -> Adds Quote generation support.
Patch 3/3 -> Adds selftest support for Quote generation feature.

[1] https://cdrdv2.intel.com/v1/dl/getContent/726790, section titled "TDG.VP.VMCALL<GetQuote>".
[2] https://lore.kernel.org/lkml/CAAYXXYxxs2zy_978GJDwKfX5Hud503gPc8=[e-mail]/
[3] https://lore.kernel.org/lkml/[e-mail]/

Kuppuswamy Sathyanarayanan (3):
  x86/tdx: Add TDX Guest event notify interrupt support
  virt: tdx-guest: Add Quote generation support
  selftests/tdx: Test GetQuote TDX attestation feature

 Documentation/virt/coco/tdx-guest.rst        |  11 +
 arch/x86/coco/tdx/tdx.c                      | 203 +++++++++++++++
 arch/x86/include/asm/tdx.h                   |   8 +
 drivers/virt/coco/tdx-guest/tdx-guest.c      | 249 ++++++++++++++++++-
 include/uapi/linux/tdx-guest.h               |  44 ++++
 tools/testing/selftests/tdx/tdx_guest_test.c |  68 ++++-
 6 files changed, 575 insertions(+), 8 deletions(-)

Comments

Erdem Aktas March 27, 2023, 5:36 p.m. UTC | #1

On Sat, Mar 25, 2023 at 11:20 PM Kuppuswamy Sathyanarayanan
<[e-mail]> wrote:
>
> Hi All,
>
> In TDX guest, the attestation process is used to verify the TDX guest
> trustworthiness to other entities before provisioning secrets to the
> guest.
>
> The TDX guest attestation process consists of two steps:
>
> 1. TDREPORT generation
> 2. Quote generation.
>
> The First step (TDREPORT generation) involves getting the TDX guest
> measurement data in the format of TDREPORT which is further used to
> validate the authenticity of the TDX guest. The second step involves
> sending the TDREPORT to a Quoting Enclave (QE) server to generate a
> remotely verifiable Quote. TDREPORT by design can only be verified on
> the local platform. To support remote verification of the TDREPORT,
> TDX leverages Intel SGX Quoting Enclave to verify the TDREPORT
> locally and convert it to a remotely verifiable Quote. Although
> attestation software can use communication methods like TCP/IP or
> vsock to send the TDREPORT to QE, not all platforms support these
> communication models. So TDX GHCI specification [1] defines a method
> for Quote generation via hypercalls. Please check the discussion from
> Google [2] and Alibaba [3] which clarifies the need for hypercall based
Thanks Sathyanarayanan for submitting patches again.

I just wanted to reiterate what I said before that having a clean
TDVMCALL based interface to get TDX Quote without any virtio/vsock
dependency  is critical for us to support many use cases.

Dionna Amalie Glaze March 28, 2023, 7:59 p.m. UTC | #2

+Chong Cai

Adding a colleague per his request since he's not subscribed to the list yet.

On Mon, Mar 27, 2023 at 10:36 AM Erdem Aktas <[e-mail]> wrote:
>
> On Sat, Mar 25, 2023 at 11:20 PM Kuppuswamy Sathyanarayanan
> <[e-mail]> wrote:
> >
> > Hi All,
> >
> > In TDX guest, the attestation process is used to verify the TDX guest
> > trustworthiness to other entities before provisioning secrets to the
> > guest.
> >
> > The TDX guest attestation process consists of two steps:
> >
> > 1. TDREPORT generation
> > 2. Quote generation.
> >
> > The First step (TDREPORT generation) involves getting the TDX guest
> > measurement data in the format of TDREPORT which is further used to
> > validate the authenticity of the TDX guest. The second step involves
> > sending the TDREPORT to a Quoting Enclave (QE) server to generate a
> > remotely verifiable Quote. TDREPORT by design can only be verified on
> > the local platform. To support remote verification of the TDREPORT,
> > TDX leverages Intel SGX Quoting Enclave to verify the TDREPORT
> > locally and convert it to a remotely verifiable Quote. Although
> > attestation software can use communication methods like TCP/IP or
> > vsock to send the TDREPORT to QE, not all platforms support these
> > communication models. So TDX GHCI specification [1] defines a method
> > for Quote generation via hypercalls. Please check the discussion from
> > Google [2] and Alibaba [3] which clarifies the need for hypercall based
> Thanks Sathyanarayanan for submitting patches again.
>
> I just wanted to reiterate what I said before that having a clean
> TDVMCALL based interface to get TDX Quote without any virtio/vsock
> dependency  is critical for us to support many use cases.

Chong Cai March 28, 2023, 8:43 p.m. UTC | #3

On Tue, Mar 28, 2023 at 12:59 PM Dionna Amalie Glaze
<[e-mail]> wrote:
>
> +Chong Cai
>
> Adding a colleague per his request since he's not subscribed to the list yet.
>
> On Mon, Mar 27, 2023 at 10:36 AM Erdem Aktas <[e-mail]> wrote:
> >
> > On Sat, Mar 25, 2023 at 11:20 PM Kuppuswamy Sathyanarayanan
> > <[e-mail]> wrote:
> > >
> > > Hi All,
> > >
> > > In TDX guest, the attestation process is used to verify the TDX guest
> > > trustworthiness to other entities before provisioning secrets to the
> > > guest.
> > >
> > > The TDX guest attestation process consists of two steps:
> > >
> > > 1. TDREPORT generation
> > > 2. Quote generation.
> > >
> > > The First step (TDREPORT generation) involves getting the TDX guest
> > > measurement data in the format of TDREPORT which is further used to
> > > validate the authenticity of the TDX guest. The second step involves
> > > sending the TDREPORT to a Quoting Enclave (QE) server to generate a
> > > remotely verifiable Quote. TDREPORT by design can only be verified on
> > > the local platform. To support remote verification of the TDREPORT,
> > > TDX leverages Intel SGX Quoting Enclave to verify the TDREPORT
> > > locally and convert it to a remotely verifiable Quote. Although
> > > attestation software can use communication methods like TCP/IP or
> > > vsock to send the TDREPORT to QE, not all platforms support these
> > > communication models. So TDX GHCI specification [1] defines a method
> > > for Quote generation via hypercalls. Please check the discussion from
> > > Google [2] and Alibaba [3] which clarifies the need for hypercall based
> > Thanks Sathyanarayanan for submitting patches again.
> >
> > I just wanted to reiterate what I said before that having a clean
> > TDVMCALL based interface to get TDX Quote without any virtio/vsock
> > dependency  is critical for us to support many use cases.
>
> +1 to Erdem's point. A simple TDVMCALL interface could make it much
> easier for user cases that can not depend on virtio and vsock.
> Without the TDVMCALL, it will largely limit those user cases to adopt TDX.
> Thanks Sathyanarayanan for submitting this patch.
> --
> -Dionna Glaze, PhD (she/her)