On 10/18/22 19:04, Stefan Berger wrote:
This series of patches adds support for migrating vTPMs across hosts whose storage has been set up to share the directory structure holding the state of the TPM (swtpm). The existence of share storage influences the management of the directory structure holding the TPM state, which for example is only removed when a domain is undefined and not when a VM is removed on the migration source host. Further, when shared storage is used then security labeling on the destination side is skipped assuming that the labeling was already done on the source side.
I have tested this with an NFS setup where I had to turn SELinux off on the hosts since the SELinux MLS range labeling is not supported by NFS.
For shared storage support to work properly both sides of the migration need to be clients of the shared storage setup, meaning that they both have to have /var/lib/libvirt/swtpm mounted as shared storage, because other- wise the virFileIsSharedFS() may not detect shared storage and in the worst case may cause the TPM emulator (swtpm) to malfunction if for example the source side removed the TPM state directory structure.
Shared storage migration requires (upcoming) swtpm v0.8.
Stefan
v3: - Relying entirely on virFileIsSharedFS() on migration source and destination sides to detect whether shared storage is set up between hosts; no more hint about shared storage from user via flag - Added support for virDomainTPMPrivate structure to store and persist TPM-related private data
Stefan Berger (6): util: Add parsing support for swtpm's cmdarg-migration capability qemu: tpm: Conditionally create storage on incoming migration qemu: tpm: Add support for storing private TPM-related data qemu: tpm: Pass --migration option to swtpm if supported and needed qemu: tpm: Avoid security labels on incoming migration with shared storage qemu: tpm: Never remove state on outgoing migration and shared storage
src/conf/domain_conf.c | 63 ++++++++++++++++++++-- src/conf/domain_conf.h | 9 ++++ src/qemu/qemu_domain.c | 85 +++++++++++++++++++++++++++-- src/qemu/qemu_domain.h | 17 +++++- src/qemu/qemu_driver.c | 20 +++---- src/qemu/qemu_extdevice.c | 10 ++-- src/qemu/qemu_extdevice.h | 6 ++- src/qemu/qemu_migration.c | 20 ++++--- src/qemu/qemu_process.c | 9 ++-- src/qemu/qemu_snapshot.c | 4 +- src/qemu/qemu_tpm.c | 111 ++++++++++++++++++++++++++++++++++---- src/qemu/qemu_tpm.h | 12 ++++- src/util/virtpm.c | 1 + src/util/virtpm.h | 1 + 14 files changed, 318 insertions(+), 50 deletions(-)
Patches look good. I did an experiment and tried to rework the code that patch 3/6 is not needed. You can find it here: https://gitlab.com/MichalPrivoznik/libvirt/-/commits/tpm_migration_rework If you don't like it, I can merge your patches as they are. Or, let me know if you're okay with my changes. No need to resend either way. Michal