[libvirt] [PATCH 06/10] vcpubandwidth: introduce two new libvirt APIs

[Wen Congyang]

At 06/30/2011 11:13 AM, Wen Congyang Write:
> We want to control bandwidth for each vcpu, so we can not use the
> API virDomainSetSchedulerParameters(). Introduce two new APIs to
> change and query bandwidth for each vcpu.
> 


> +
> +/**
> + * virDomainSetVcpuBW:
> + * @domain: pointer to domain object
> + * @params: pointer to vcpu bandwidth objects

another typo error:
s/params/vcpubw/

> + * @nparams: number of vcpu bandwidth objects

s/nparams/nvcpubw/

> + *          (this value can be the same or less than domain's vcpu num)
> + * @flags: bitwise-OR of virDomainModificationImpact
> + *
> + * Change a subset or all vcpu bandwidth.  The value of @flags
> + * should be either VIR_DOMAIN_AFFECT_CURRENT, or a bitwise-or of
> + * values from VIR_DOMAIN_AFFECT_LIVE and VIR_DOMAIN_AFFECT_CONFIG,
> + * although hypervisors vary in which flags are supported.
> + *
> + * Returns -1 in case of error, 0 in case of success.
> + */
> +int
> +virDomainSetVcpuBW(virDomainPtr domain, virDomainVcpuBWDefPtr vcpubw,
> +                   int nvcpu, unsigned int flags)
> +{
> +    virConnectPtr conn;
> +
> +    VIR_DOMAIN_DEBUG(domain, "vcpubw=%p, nvcpu=%d, flags=%u",
> +                     vcpubw, nvcpu, flags);
> +
> +    virResetLastError();
> +
> +    if (!VIR_IS_CONNECTED_DOMAIN(domain)) {
> +        virLibDomainError(VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
> +        virDispatchError(NULL);
> +        return -1;
> +    }
> +
> +    if (vcpubw == NULL || nvcpu < 0) {
> +        virLibDomainError(VIR_ERR_INVALID_ARG, __FUNCTION__);
> +        goto error;
> +    }
> +
> +    if (domain->conn->flags & VIR_CONNECT_RO) {
> +        virLibDomainError(VIR_ERR_OPERATION_DENIED, __FUNCTION__);
> +        goto error;
> +    }
> +    conn = domain->conn;
> +
> +    if (conn->driver->domainSetVcpuBW) {
> +        int ret;
> +        ret = conn->driver->domainSetVcpuBW(domain, vcpubw, nvcpu, flags);
> +        if (ret < 0)
> +            goto error;
> +        return ret;
> +    }
> +
> +    virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
> +
> +error:
> +    virDispatchError(domain->conn);
> +    return -1;
> +}
> +
>  
>  /**
>   * virDomainBlockStats:
> diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
> index 5f2541a..d4f80a6 100644
> --- a/src/libvirt_public.syms
> +++ b/src/libvirt_public.syms
> @@ -466,4 +466,10 @@ LIBVIRT_0.9.3 {
>          virNodeGetMemoryStats;
>  } LIBVIRT_0.9.2;
>  
> +LIBVIRT_0.9.4 {
> +    global:
> +        virDomainGetVcpuBW;
> +        virDomainSetVcpuBW;
> +} LIBVIRT_0.9.3;
> +
>  # .... define new API here using predicted next version number ....