[libvirt] [PATCH v4 20/23] tpm: Pass migration key passphrase via fd to swtpm

This patch now passes the passphrase as a migration key to swtpm. This now encrypts the state of the TPM while a VM is migrated between hosts or when suspended into a file. Since the migration key secret is the same as the state encryption secret, this now requires that the migration destination host has the same secret value. Signed-off-by: Stefan Berger <stefanb(a)linux.ibm.com&gt; --- src/qemu/qemu_tpm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_tpm.c b/src/qemu/qemu_tpm.c index 880b0642c6..a51e3afee2 100644 --- a/src/qemu/qemu_tpm.c +++ b/src/qemu/qemu_tpm.c @@ -575,6 +575,7 @@ qemuTPMEmulatorBuildCommand(virDomainTPMDefPtr tpm, bool created = false; char *pidfile; VIR_AUTOCLOSE pwdfile_fd = -1; + VIR_AUTOCLOSE migpwdfile_fd = -1; if (qemuTPMCreateEmulatorStorage(tpm->data.emulator.storagepath, &created, swtpm_user, swtpm_group) < 0) @@ -636,7 +637,9 @@ qemuTPMEmulatorBuildCommand(virDomainTPMDefPtr tpm, } pwdfile_fd = qemuTPMSetupEncryption(tpm->data.emulator.encryption, cmd); - if (pwdfile_fd < 0) + migpwdfile_fd = qemuTPMSetupEncryption(tpm->data.emulator.encryption, + cmd); + if (pwdfile_fd < 0 || migpwdfile_fd < 0) goto error; virCommandAddArg(cmd, "--key"); @@ -644,6 +647,12 @@ qemuTPMEmulatorBuildCommand(virDomainTPMDefPtr tpm, pwdfile_fd); virCommandPassFD(cmd, pwdfile_fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT); pwdfile_fd = -1; + + virCommandAddArg(cmd, "--migration-key"); + virCommandAddArgFormat(cmd, "pwdfd=%d,mode=aes-256-cbc,kdf=pbkdf2", + migpwdfile_fd); + virCommandPassFD(cmd, migpwdfile_fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT); + migpwdfile_fd = -1; } return cmd; -- 2.20.1