On Fri, Jul 16, 2021 at 11:10:28AM +0800, Zhenzhong Duan wrote:
Thanks Peter, Pavel and Daniel's comments on v1 version, now the v2 comes.
* What's TDX? TDX stands for Trust Domain Extensions which isolates VMs from the virtual-machine manager (VMM)/hypervisor and any other software on the platform.
To support TDX, multiple software components, not only KVM but also QEMU, guest Linux and virtual bios, need to be updated. For more details, please check link[1], there are TDX spec links and public repository link at github for each software component.
This patchset is another software component to extend libvirt to support TDX, with which one can start a VM from high level rather than running qemu directly.
* The goal of this RFC patch The purpose of this post is to get feedback early on high level design issue of libvirt enhancement for TDX. Referenced much on AMD SEV and S390 PV implemention at link[2][3]. This 2nd version is rebased on upstream + s390 v4 version as shown in [3] to utilize the common launchsecurity framework code.
* Patch organization - patch 1-3: Support query of TDX capabilities. - patch 4-6: Add TDX type to launchsecurity framework. - patch 7: Add general loader support for TDX. - patch 8: Add firmware descriptor support for TDX.
* Misc Just let you know we have released v2 version of TDX qemu in [1], and the API for libvirt is keeping stable. Using these patches we have succesfully booted and tested a guest both with and without TDX enabled.
Overall looks good. It's missing documentation and the QEMU patches are missing documentation as well. I was looking into Intel specification but I failed to find the necessary info there as well. What are the values `mrconfigid`, `mrowner`, `mrownerconfig` for, what data is supposed to be stored there, what are the limitation and so on. What I could gather these are exposed in the VM and are used for measurement but that's it. Another thing that I've missed in v1, QEMU patches are introducing new `-machine pic=no` option and for TDX PIC has to be disabled. The libvirt patches are putting it on the QEMU command line but it is not reflected in the VM XML, so I would say we need to introduce new hypervisor feature [1]: <features> ... <pic state='on|off'/> ... </features> [1] <https://libvirt.org/formatdomain.html#hypervisor-features>
* Diff to v1: - give up using qmp cmd and check TDX directly on host for TDX capabilities. - use launchsecurity framework to support TDX - use <os>.<loader> for general loader - add auto firmware match feature for TDX
A example TDVF fimware description file 70-edk2-x86_64-tdx.json: { "description": "UEFI firmware for x86_64, supporting Intel TDX", "interface-types": [ "uefi" ], "mapping": { "device": "generic",
I think using 'loader' as that's the actual device in QEMU used with this firmware will be better. The patches posted to QEMU doesn't extend `docs/interop/firmware.json` so this example may change once some specific format is accepted by QEMU community. You will most likely need to add the firmware descriptor to QEMU project as well (`pc-bios/descriptors/70-edk2-x86_64-tdx.json`). NOTE: The name should not use `edk2` if it's not edk2 based firmware. Pavel
"filename": "/usr/share/OVMF/OVMF_CODE-tdx.fd" }, "targets": [ { "architecture": "x86_64", "machines": [ "pc-q35-*" ] } ], "features": [ "intel-tdx", "verbose-dynamic" ], "tags": [
] }
Links: [1] https://lists.nongnu.org/archive/html/qemu-devel/2021-07/msg01682.html [2] https://github.com/codomania/libvirt/commits/v9 [3] https://www.mail-archive.com/libvir-list@redhat.com/msg219144.html
Zhenzhong Duan (8): qemu: Check if INTEL Trust Domain Extention support is enabled qemu: Add TDX capability conf: expose TDX feature in domain capabilities conf: add tdx as launch security type qemu: Add command line and validation for TDX type qemu: force special parameters enabled for TDX guest qemu: Add general loader support qemu: Add firmware descriptor support for TDX
docs/formatdomaincaps.html.in | 17 ++++++ docs/schemas/domaincaps.rng | 9 +++ docs/schemas/domaincommon.rng | 18 ++++++ src/conf/domain_capabilities.c | 1 + src/conf/domain_capabilities.h | 1 + src/conf/domain_conf.c | 49 ++++++++++++++++ src/conf/domain_conf.h | 11 ++++ src/conf/virconftypes.h | 2 + src/qemu/qemu_capabilities.c | 44 ++++++++++++++- src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 38 +++++++++++++ src/qemu/qemu_firmware.c | 100 ++++++++++++++++++++++++++++++++- src/qemu/qemu_namespace.c | 2 + src/qemu/qemu_process.c | 1 + src/qemu/qemu_validate.c | 28 +++++++++ 15 files changed, 319 insertions(+), 3 deletions(-)
-- 2.25.1