Re: [PATCH v5 23/23] backends/tpm: Propagate vTPM error on migration failure

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Jul 17, 2025 at 06:07:46AM +0530, Arun Menon wrote:
> - When migration of a VM with encrypted vTPM fails on the
>   destination host, (e.g., due to a mismatch in secret values),
>   the error message displayed on the source host is generic and unhelpful.
> - For example, a typical error looks like this:
>   "operation failed: job 'migration out' failed: Sibling indicated error 1.
>   operation failed: job 'migration in' failed: load of migration failed:
>   Input/output error"
> - Such generic errors are logged using error_report(), which prints to
>   the console/monitor but does not make the detailed error accessible via
>   the QMP query-migrate command.
> - This change, along with the set of changes of passing errp Error object
>   to the VM state loading functions, help in addressing the issue.
>   We use the post_load_errp hook of VMStateDescription to propagate errors
>   by setting Error **errp objects in case of failure in the TPM backend.
> - It can then be retrieved using QMP command:
>   {"execute" : "query-migrate"}
> 
> Buglink: https://issues.redhat.com/browse/RHEL-82826
> 
> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
> Signed-off-by: Arun Menon <armenon@redhat.com>
> ---
>  backends/tpm/tpm_emulator.c | 39 ++++++++++++++++++++-------------------
>  1 file changed, 20 insertions(+), 19 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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