On Mon, Jun 30, 2025 at 02:17:18PM +0800, Zhenzhong Duan wrote:
When 'tdx' is used, the VM will be launched with Intel TDX feature enabled. TDX feature supports running encrypted VM (Trust Domain, TD) under the control of KVM. A TD runs in a CPU model which protects the confidentiality of its memory and its CPU state from other software.
There are four optional child elements. Element policy is 64bit hex, bit 0 is set to enable TDX debug, bit 28 is set to enable sept-ve-disable, other bits are reserved currently. When policy isn't specified, QEMU will use its own default value 0x10000000. mrConfigId, mrOwner and mrOwnerConfig are base64 encoded SHA384 digest string.
For example:
<launchSecurity type='tdx'> <policy>0x10000001</policy> <mrConfigId>xxx</mrConfigId> <mrOwner>xxx</mrOwner> <mrOwnerConfig>xxx</mrOwnerConfig> </launchSecurity>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> --- src/conf/domain_conf.c | 49 +++++++++++++++++++++++++++++++ src/conf/domain_conf.h | 11 +++++++ src/conf/domain_validate.c | 1 + src/conf/schemas/domaincommon.rng | 32 ++++++++++++++++++++ src/conf/virconftypes.h | 2 ++ src/qemu/qemu_cgroup.c | 1 + src/qemu/qemu_command.c | 2 ++ src/qemu/qemu_driver.c | 1 + src/qemu/qemu_firmware.c | 1 + src/qemu/qemu_namespace.c | 1 + src/qemu/qemu_process.c | 2 ++ src/qemu/qemu_validate.c | 1 + src/security/security_dac.c | 2 ++ 13 files changed, 106 insertions(+)
diff --git a/src/qemu/qemu_firmware.c b/src/qemu/qemu_firmware.c index 2d0ec0b4fa..6c65a2751b 100644 --- a/src/qemu/qemu_firmware.c +++ b/src/qemu/qemu_firmware.c @@ -1371,6 +1371,7 @@ qemuFirmwareMatchDomain(const virDomainDef *def, } break; case VIR_DOMAIN_LAUNCH_SECURITY_PV: + case VIR_DOMAIN_LAUNCH_SECURITY_TDX: break; case VIR_DOMAIN_LAUNCH_SECURITY_NONE: case VIR_DOMAIN_LAUNCH_SECURITY_LAST:
We need a patch in this series that updates qemuFirmwareMatchDomain to handle TDX guests. Currently with <os firmware="efi"> <type arch="x86_64" machine="q35">hvm</type> <boot dev="hd"/> </os> we are *not* matching the right firmware imagte qemuFirmwareMatchDomain:1383 : Firmware '/usr/share/qemu/firmware/30-edk2-ovmf-4m-qcow2-x64-sb-enrolled.json' matches domain requirements qemuFirmwareFillDomainModern:1743 : Found matching firmware (description path '/usr/share/qemu/firmware/30-edk2-ovmf-4m-qcow2-x64-sb-enrolled.json') qemuFirmwareEnableFeaturesModern:1439 : decided on firmware '/usr/share/edk2/ovmf/OVMF_CODE_4M.secboot.qcow2' template '/usr/share/edk2/ovmf/OVMF_VARS_4M.secboot.qcow2' qemuFirmwareEnableFeaturesModern:1473 : Enabling SMM feature qemuFirmwareEnableFeaturesModern:1476 : Enabling secure loader and so we fail to boot as SMM is incompatible with TDX, as well as incorrectly setting up separate NVRAM. The file we should have matched is /usr/share/qemu/firmware/60-edk2-ovmf-x64-inteltdx.json Which has the right feature for TDX launch security: "features": [ "enrolled-keys", "intel-tdx", "secure-boot", "verbose-dynamic" ], there is already logic in qemu_firmware.c for SEV/SNP, and the same design pattern should work for TDX too. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|