On 7 Sep 2026, at 2:26 PM, Abhisek Panda <abhisek.panda1@nutanix.com> wrote:
QEMU provides the capability to encrypt the migration data stream using two transport layer security (TLS) authentication schemes: X.509 certificates and pre-shared keys (PSK). Currently, Libvirt only supports the X.509-based TLS authentication scheme. In TLS X.509 certificates, a set of live migrations utilize a fixed set of static certificates for encrypted migration. In this authentication scheme, users require to deploy a certificate authority and monitor the certificate expiration window. In case certificates are compromised all the future live migrations are vulnerable.
To resolve this, this patch series introduce the support for pre-shared key-based authentication scheme. This mechanism relies on symmetric pre-shared keys (a secret key that is known to both sender and receiver prior to secure communication) for providing secure transfer of data. Libvirt solely manages the lifecycle of the ephemeral pre-shared keys, including, generation, persistent storage, and cleanup. Libvirt generates the key on the source machine, then transfers it to the destination machine using the migration cookie. To allow users to configure the size of the key, Libvirt provides the migrate_tls_psk_length configuration parameter in qemu.conf.
We enable the PSK-based TLS authentication scheme if both source and destination supports the tls-creds-psk object regardless of the value of VIR_MIGRATE_TLS flag. Else, we use the X.509-based TLS authentication scheme if the VIR_MIGRATE_TLS flag is set.
v4: 1. Enable TLS-PSK if source and destination supports it regardless of the VIR_MIGRATE_TLS flag. 2. If either source or destination does not support TLS-PSK and the VIR_MIGRATE_TLS flag is set then fallback to TLS X509
v3: 1. Destination host decides which TLS authentication scheme to use. 2. The directory of the key file is set to <tls_psk_state_dir>/$ID-$VMNAME. 3. Use the same alias for both tls-creds-x509 and tls-creds-psk objects. 4. Validate the length of the pre-shared key. 5. Unit test to validate the pre-shared key in the migration cookie.
v2: 1. Libvirt manages the lifecycle of pre-shared keys. 2. Transfer of keys to the destination via the migration cookie 3. Remove the VIR_MIGRATE_TLS_PSK flag instead rely on VIR_MIGRATE_TLS and availability of ca-cert.pem on source. 4. Drop VIR_MIGRATE_PARAM_TLS_PSK_DIRECTORY, Libvirt solely manages the pre-shared keys.
Abhisek Panda (7): conf: Add a configuration param for TLS-PSK qemu: Manage a pre-shared key's lifecycle qemu: Add support to build the tls-creds-psk object qemu: rename tls-creds-x509 obj related functions qemu: Manage tls-creds-psk object lifecycle qemu: Set up the migrate TLS-PSK objects tests: Add testing of pre-shared key lifecycle
include/libvirt/libvirt-domain.h | 10 +- src/qemu/libvirtd_qemu.aug | 1 + src/qemu/qemu.conf.in | 8 + src/qemu/qemu_capabilities.c | 2 + src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 26 +++ src/qemu/qemu_command.h | 7 + src/qemu/qemu_conf.c | 22 +++ src/qemu/qemu_conf.h | 2 + src/qemu/qemu_domain.c | 1 + src/qemu/qemu_domain.h | 1 + src/qemu/qemu_driver.c | 6 + src/qemu/qemu_hotplug.c | 40 ++--- src/qemu/qemu_hotplug.h | 24 +-- src/qemu/qemu_migration.c | 170 +++++++++++++++--- src/qemu/qemu_migration.h | 3 + src/qemu/qemu_migration_cookie.c | 79 +++++++- src/qemu/qemu_migration_cookie.h | 5 + src/qemu/qemu_migration_params.c | 98 ++++++++-- src/qemu/qemu_migration_params.h | 22 ++- src/qemu/qemu_process.c | 3 + src/qemu/test_libvirtd_qemu.aug.in | 1 + .../caps_10.0.0_aarch64.xml | 1 + .../caps_10.0.0_ppc64.xml | 1 + .../caps_10.0.0_s390x.xml | 1 + .../caps_10.0.0_x86_64+amdsev.xml | 1 + .../caps_10.0.0_x86_64.xml | 1 + .../caps_10.1.0_s390x.xml | 1 + .../caps_10.1.0_x86_64+inteltdx.xml | 1 + .../caps_10.1.0_x86_64.xml | 1 + .../caps_10.2.0_aarch64.xml | 1 + .../caps_10.2.0_x86_64+mshv.xml | 1 + .../caps_10.2.0_x86_64.xml | 1 + .../caps_11.0.0_aarch64.xml | 1 + .../caps_11.0.0_s390x.xml | 1 + .../caps_11.0.0_x86_64+sgx.xml | 1 + .../caps_11.0.0_x86_64.xml | 1 + .../caps_11.1.0_aarch64.xml | 1 + .../caps_11.1.0_s390x.xml | 1 + .../caps_11.1.0_x86_64.xml | 1 + tests/qemucapabilitiesdata/caps_7.2.0_ppc.xml | 1 + .../caps_7.2.0_x86_64+hvf.xml | 1 + .../caps_7.2.0_x86_64.xml | 1 + .../caps_8.0.0_x86_64.xml | 1 + .../qemucapabilitiesdata/caps_8.1.0_s390x.xml | 1 + .../caps_8.1.0_x86_64.xml | 1 + .../caps_8.2.0_aarch64.xml | 1 + .../caps_8.2.0_armv7l.xml | 1 + .../caps_8.2.0_loongarch64.xml | 1 + .../qemucapabilitiesdata/caps_8.2.0_s390x.xml | 1 + .../caps_8.2.0_x86_64.xml | 1 + .../qemucapabilitiesdata/caps_9.0.0_sparc.xml | 1 + .../caps_9.0.0_x86_64.xml | 1 + .../caps_9.1.0_riscv64.xml | 1 + .../qemucapabilitiesdata/caps_9.1.0_s390x.xml | 1 + .../caps_9.1.0_x86_64.xml | 1 + .../caps_9.2.0_aarch64+hvf.xml | 1 + .../qemucapabilitiesdata/caps_9.2.0_s390x.xml | 1 + .../caps_9.2.0_x86_64+amdsev.xml | 1 + .../caps_9.2.0_x86_64.xml | 1 + tests/qemumigrationcookiexmltest.c | 135 +++++++++++++- tests/testutilsqemu.c | 12 ++ 62 files changed, 632 insertions(+), 85 deletions(-)
-- 2.43.7
Ping for the series. Checking in to see if anyone has feedback on this patch set. Thanks and warm regards Dr. Abhisek Panda