Hi On Fri, May 27, 2022 at 7:36 PM Stefan Berger <stef...@linux.ibm.com> wrote: > > This series of patches resolves an issue with a TPM 2's dictionary attack > lockout logic being triggered upon well-timed VM resets. Normally, the OS > TPM driver sends a TPM2_Shutdown to the TPM 2 upon reboot and before a VM > is reset. However, the OS driver cannot do this when the user resets a VM. > In this case QEMU must send the command because otherwise several well- > timed VM resets will trigger the TPM 2's dictionary attack (DA) logic and > it will then refuse to do certain key-related operations until the DA > logic has timed out.
How does real hardware deal with that situation? Shouldn't this "shutdown"/reset logic be implemented on swtpm side instead, when CMD_INIT is received? (when the VM is restarted) > > Regards, > Stefan > > Stefan Berger (2): > backends/tpm: Record the last command sent to the TPM > backends/tpm: Send TPM2_Shutdown upon VM reset > > backends/tpm/tpm_emulator.c | 44 +++++++++++++++++++++++++++++++++++++ > backends/tpm/tpm_int.h | 3 +++ > backends/tpm/tpm_util.c | 9 ++++++++ > backends/tpm/trace-events | 1 + > include/sysemu/tpm_util.h | 3 +++ > 5 files changed, 60 insertions(+) > > -- > 2.35.3 >
