Re: [PATCH 06/21] migration: Remove checks for s->parameters has_* fields

[Peter Xu <peterx@redhat.com>]

On Mon, Jun 02, 2025 at 10:37:55PM -0300, Fabiano Rosas wrote:
> The migration parameters validation produces a temporary structure
> which is the merge of the current parameter values (s->parameters,
> MigrationParameters) with the new parameters set by the user
> (MigrateSetParameters).
> 
> When copying the values from s->parameters into the temporary
> structure, the has_* fields are copied along, but when merging the
> user-input values (MigrateSetParameters) they are not.
> 
> During migrate_params_check(), only the parameters that have the
> corresponding has_* field will be checked, so only the parameters that
> were initialized in migrate_params_init() will be validated.
> 
> This causes (almost) all of the migration parameters to be validated
> every time a parameter is set, regardless of which fields the user
> touched, but it also skips validation of any values that are not set
> in migrate_params_init().
> 
> It's not clear what was the intention of the original code, whether to
> validate all fields always, or only validate what the user input
> changed. Since the current situation is closer to the former option,
> make the choice of validating all parameters by removing the checks
> for the has_* fields when validating.
> 
> Note that bringing the user input into the temporary structure for
> validation still needs to look at the has_* fields, otherwise any
> parameters not set by the user (i.e. 0) would override the
> corresponding value in s->parameters.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu