Commit Graph

15 Commits

Author SHA1 Message Date
Han Han
6beeca77be vir-qemu-sev-validate: Use string() method in xpath
For the xpath "/domain/cpu/@mode", it will return a list type not a
string. Use string() method in the xpath for the string result.

Fixes: 6b95437c17

Signed-off-by: Han Han <hhan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2023-12-05 12:21:38 +01:00
Daniel P. Berrangé
120724bc6d tools: fix VMSA construction with explicit CPU family/model/stepping
If the CPU family/model/stepping are provided on the command line, but
the firmware is being automatically extracted from the libvirt guest,
we try to build the VMSA too early. This leads to an exception trying
to parse the firmware that has not been loaded yet. We must delay
building the VMSA in that scenario.

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2023-08-29 11:44:59 +01:00
Daniel P. Berrangé
6b95437c17 tools: fix handling of CPU family/model/stepping in SEV validation
The SEV-ES boot measurement includes the initial CPU register state
(VMSA) and one of the fields includes the CPU identification. When
building a VMSA blob we get the CPU family/model/stepping from the
host capabilities, however, the VMSA must reflect the guest CPU not
host CPU. Thus using host capabilities is only when whe the guest
has the 'host-passthrough' CPU mode active. With 'host-model' it is
cannot be assumed host and guest match, because QEMU may not (yet)
have a named CPU model for a given host CPU.

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2023-08-29 11:44:59 +01:00
Han Han
28141adfdc scripts: Fix the flake8 syntax-check failures
Fix the syntax-check failures (which can be seen after
python3-flake8-import-order package is installed) with the help
of isort[1]:

289/316 libvirt:syntax-check / flake8   FAIL   5.24s   exit status 2

[1]: https://pycqa.github.io/isort/

Signed-off-by: Han Han <hhan@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2023-06-29 11:51:27 +02:00
Jim Fehlig
0f350a4d07 tools: Fix detection of remote libvirt access in virt-qemu-sev-validate
The VM's firmware path is not extracted from the XML when invoking
virt-qemu-sev-validate in insecure mode and connecting to the local libvirt

virt-qemu-sev-validate --insecure --tk tek-tik.bin --domain test-sev-es
ERROR: Cannot access firmware path remotely

The test for remote access compares the return value from socket.gethostname()
to the return value from conn.getHostname(). The former doesn't always return
the fqdn, whereas the latter does. Use socket.getfqdn() instead.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2023-02-03 11:28:56 -07:00
Andrea Bolognani
6c4f5af9a0 tools: Fix style issues in virt-qemu-sev-validate
The script had an incorrect interpreter line until commit
f6a19d7264, so the flake8 check would not realize it needed
to pick it up and these issues, some of which were present it
the very first version that was committed, were not being
reported.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-12-08 18:09:29 +01:00
Andrea Bolognani
f6a19d7264 tools: Fix interpreter for virt-qemu-sev-validate
Go through env(1) instead of hardcoding the path to the Python
interpreter, as we already do for all other Python scripts.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-12-08 17:24:21 +01:00
Daniel P. Berrangé
b348f37445 tools: support generating SEV secret injection tables
It is possible to build OVMF for SEV with an embedded Grub that can
fetch LUKS disk secrets. This adds support for injecting secrets in
the required format.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
273c408899 tools: load CPU count and CPU SKU from libvirt
When validating a SEV-ES guest, we need to know the CPU count and VMSA
state. We can get the CPU count directly from libvirt's guest info. The
VMSA state can be constructed automatically if we query the CPU SKU from
host capabilities XML. Neither of these is secure, however, so this
behaviour is restricted.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
676df5b358 tools: support automatically constructing SEV-ES vCPU state
The VMSA files contain the expected CPU register state for the VM. Their
content varies based on a few pieces of the stack

  - AMD CPU architectural initial state
  - KVM hypervisor VM CPU initialization
  - QEMU userspace VM CPU initialization
  - AMD CPU SKU (family/model/stepping)

The first three pieces of information we can obtain through code
inspection. The last piece of information we can take on the command
line. This allows a user to validate a SEV-ES guest merely by providing
the CPU SKU information, using --cpu-family, --cpu-model,
--cpu-stepping. This avoids the need to obtain or construct VMSA files
directly.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
3e7b7da9e0 tools: support validating SEV-ES initial vCPU state measurements
With the SEV-ES policy the VMSA state of each vCPU must be included in
the measured data. The VMSA state can be generated using the 'sevctl'
tool, by telling it a QEMU VMSA is required, and passing the hypevisor's
CPU SKU (family, model, stepping).

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
7d55c815c6 tools: load direct kernel config from libvirt
When connected to libvirt we can validate that the guest configuration
has the kernel hashes property enabled, otherwise including the kernel
GUID table in our expected measurements is not likely to match the
actual measurement.

When running locally we can also automatically detect the kernel/initrd
paths, along with the cmdline string from the XML.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
0b9e70b141 tools: support validating SEV direct kernel boot measurements
When doing direct kernel boot we need to include the kernel, initrd and
cmdline in the measurement.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
0e911045ae tools: load guest config from libvirt
Accept information about a connection to libvirt and a guest on the
command line. Talk to libvirt to obtain the running guest state and
automatically detect as much configuration as possible.

It will refuse to use a libvirt connection that is thought to be local
to the current machine, as running this tool on the hypervisor itself is
not considered secure. This can be overridden using the --insecure flag.

When querying the guest, it will also analyse the XML configuration in
an attempt to detect any options that are liable to be mistakes. For
example the NVRAM being measured should not have a persistent varstore.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00
Daniel P. Berrangé
ececdbdfc0 tools: support validating SEV firmware boot measurements
The virt-qemu-sev-validate program will compare a reported SEV/SEV-ES
domain launch measurement, to a computed launch measurement. This
determines whether the domain has been tampered with during launch.

This initial implementation requires all inputs to be provided
explicitly, and as such can run completely offline, without any
connection to libvirt.

The tool is placed in the libvirt-client-qemu sub-RPM since it is
specific to the QEMU driver.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-11-15 11:09:30 +00:00