Re: [PATCH 2/2] qemu: implement driver support for domainBlockRebaseParams API

[Peter Krempa via Devel]

On Thu, Sep 11, 2025 at 18:27:43 +0300, Nikolai Barybin via Devel wrote:
> Parse params list and pass arguments to underlying call to
> qemuDomainBlockPullCommon.
> 
> Now bandwidth unit of messurement is passed as param and passed further
> with a use of VIR_DOMAIN_BLOCK_PULL_BANDWIDTH_BYTES flag.
> virDomainBlockRebase2 doesn't use equavivalent external flag.

This still mentions the old API

> 
> Signed-off-by: Nikolai Barybin <nikolai.bary...@virtuozzo.com>
> ---
>  src/qemu/qemu_driver.c | 48 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
> 
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index ac72ea5cb0..0b7791aded 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -14634,6 +14634,53 @@ qemuDomainBlockRebase(virDomainPtr dom,
>      return ret;
>  }
>  
> +static int
> +qemuDomainBlockRebaseParams(virDomainPtr dom,
> +                            const char *path,
> +                            virTypedParameterPtr params,
> +                            int nparams,
> +                            unsigned int flags)
> +{
> +    virDomainObj *vm;
> +    size_t i = 0;
> +    unsigned long long bandwidth = 0;
> +    const char *base = NULL;
> +
> +    virCheckFlags(VIR_DOMAIN_BLOCK_REBASE_PARAMS_RELATIVE, -1);
> +
> +    if (virTypedParamsValidate(params, nparams,
> +                               VIR_DOMAIN_BLOCK_REBASE_PARAM_BASE,
> +                               VIR_TYPED_PARAM_STRING,
> +                               VIR_DOMAIN_BLOCK_REBASE_PARAM_BANDWIDTH_MIB,
> +                               VIR_TYPED_PARAM_ULLONG,
> +                               VIR_DOMAIN_BLOCK_REBASE_PARAM_BANDWIDTH_BYTES,
> +                               VIR_TYPED_PARAM_ULLONG,
> +                               NULL) < 0)
> +        return -1;
> +
> +    if (!(vm = qemuDomainObjFromDomain(dom)))
> +        return -1;
> +
> +    if (virDomainBlockRebaseParamsEnsureACL(dom->conn, vm->def) < 0)
> +        return -1;
> +
> +    for (i = 0; i < nparams; i++) {
> +        virTypedParameterPtr param = &params[i];
> +
> +        if (STREQ(param->field, 
> VIR_DOMAIN_BLOCK_REBASE_PARAM_BANDWIDTH_MIB)) {
> +            bandwidth = param->value.ul;
> +        } else if (STREQ(param->field, 
> VIR_DOMAIN_BLOCK_REBASE_PARAM_BANDWIDTH_BYTES)) {
> +            bandwidth = param->value.ul;
> +            flags |= VIR_DOMAIN_BLOCK_PULL_BANDWIDTH_BYTES;
> +        } else if (STREQ(param->field, VIR_DOMAIN_BLOCK_REBASE_PARAM_BASE)) {
> +            base = param->value.s;
> +        }
> +    }
> +
> +    return qemuDomainBlockPullCommon(vm, path, base, bandwidth, flags);

You're doing the implementation backwards if you want to later extend
this API via new parameters.

In migration code the old APIs create a list of parameters based on the
old API and pass it to a refactored new API.