Re: [PATCH v3 0/6] qemu: tpm: Add support for migration across shared storage

On 10/21/22 06:55, Michal Prívozník wrote: > 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. I think we need a v4. I have mine here: https://github.com/stefanberger/libvirt-tpm/tree/swtpm_shared_storage.v4