Ubuntu Manpage: virt-what-cvm - detect if we are running in a confidential virtual machine

NAME

       virt-what-cvm - detect if we are running in a confidential virtual machine

SUMMARY

       virt-what-cvm [options]

DESCRIPTION

       "virt-what-cvm" is a tool which can be used to detect if the program is running in a
       confidential virtual machine.

       The program prints out a list of "facts" about the confidential virtual machine, derived
       from heuristics.  One fact is printed per line.

       If nothing is printed and the script exits with code 0 (no error), then it can mean either
       that the program is running on bare-metal or the program is running inside a non-
       confidential virtual machine, or inside a type of confidential virtual machine which we
       don't know about or cannot detect.

FACTS

       amd-sev
           This is a confidential guest running with AMD SEV technology

           Status: tested on Fedora 37 QEMU+KVM

       amd-sev-es
           This is a confidential guest running with AMD SEV-ES technology

           Status: tested on Fedora 37 QEMU+KVM

       amd-sev-snp
           This is a confidential guest running with AMD SEV-SNP technology

           Status: tested on Microsoft Azure SEV-SNP CVM

           Status: tested on Fedora 38 QEMU+KVM SEV-SNP (devel snapshot)

       intel-tdx
           This is a confidential guest running with Intel TDX technology

           Status: tested on Microsoft Azure TDX CVM

       hyperv-hcl
           This is a confidential guest running unenlightened under the HyperV (Azure) HCL (Host
           Compatibility Layer). This will be paired with amd-sev-snp.

           Status: tested on Microsoft Azure SEV-SNP & TDX CVM

       s390-protvirt
           This is a confidential guest running on s390x with the Protected Virtualization
           (Secure Execution) technology

EXIT STATUS

       Programs that use or wrap "virt-what-cvm" should check that the exit status is 0 before
       they attempt to parse the output of the command.

       A non-zero exit status indicates some error, for example, an unrecognized command line
       argument.  If the exit status is non-zero then the output "facts" (if any were printed)
       cannot be guaranteed and should be ignored.

       The exit status does not have anything to do with whether the program is running on
       baremetal or under confidential virtualization, nor with whether "virt-what-cvm" managed
       detection "correctly" (which is basically unknowable given the large variety of
       virtualization systems out there)

RUNNING VIRT-WHAT-CVM FROM OTHER PROGRAMS

       "virt-what-cvm" is designed so that you can easily run it from other programs or wrap it
       up in a library.

       Your program should check the exit status (see the section above).

IMPORTANT NOTE

This program detects whether it is likely to be running within a known confidential VM,
but does NOT prove that the environment is trustworthy. To attain trust in the
environment requires an attestation report for the virtual machine, which is then verified
by an already trusted 3rd party.

The hardware features that this program relies on to establish facts about the
confidential virtualization environment, are those features whose behaviour will be proved
by verification of an attestation report.

This program MAY have false positives. ie it may report that it is a confidential VM when
it is in fact a non-confidential VM faking it.

This program SHOULD NOT have false negatives. ie it should not fail to report existance of
a confidential VM. Caveat that this only applies to environments which have been
explicitly tested.

If this program does print a fact, this can be used for enabling or disabling use of
certain features, according to whether they are appropriate for a confidential
environment. None the less, the VM MUST NOT be trusted until an attestation report is
verified.

As a protection against false negatives from this tool, environments requiring high
assurance should take one or more of these measures:

* The facts reported by this program I<SHOULD> should be measured
into one of the TPM PCRs
* The attestation report I<SHOULD> cover the facts reported by
this program
* The attestation report I<SHOULD> should cover the enablement
status of any features affected by decisions involving facts
reported by this tool

AUTHORS

       Daniel P. Berrangé <berrange @ redhat . com>

COPYRIGHT

       (C) Copyright 2023 Red Hat Inc., <http://people.redhat.com/~rjones/virt-what/>

       This program is free software; you can redistribute it and/or modify it under the terms of
       the GNU General Public License as published by the Free Software Foundation; either
       version 2 of the License, or (at your option) any later version.

       This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with this program;
       if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
       USA.

REPORTING BUGS

       Bugs can be viewed on the Red Hat Bugzilla page: <https://bugzilla.redhat.com/>.

       If you find a bug in virt-what-cvm, please follow these steps to report it:

       1. Check for existing bug reports
           Go to <https://bugzilla.redhat.com/> and search for similar bugs.  Someone may already
           have reported the same bug, and they may even have fixed it.

       2. Capture debug and error messages
           Run

            virt-what-cvm -d > virt-what-cvm.log 2>&1

           and keep virt-what-cvm.log.  It may contain error messages which you should submit
           with your bug report.

       3. Get version of virt-what-cvm.
           Run

            virt-what-cvm --version

       4. Submit a bug report.
           Go to <https://bugzilla.redhat.com/> and enter a new bug.  Please describe the problem
           in as much detail as possible.

           Remember to include the version numbers (step 3) and the debug messages file (step 2)
           and as much other detail as possible.

       5. Assign the bug to rjones @ redhat.com
           Assign or reassign the bug to rjones @ redhat.com (without the spaces).  You can also
           send me an email with the bug number if you want a faster response.