[libvirt] [PATCH v2 05/10] nodedev: conf: Split PCI sub-capability parsing to a separate method

[Pavel Hrdina]

On Thu, Apr 20, 2017 at 03:05:55PM +0200, Erik Skultety wrote:
> Since there's at least SRIOV and MDEV sub-capabilities to be parsed,
> let's make the code more readable by splitting it to several logical
> blocks.
> 
> Signed-off-by: Erik Skultety <eskultet at redhat.com>
> ---
>  src/conf/node_device_conf.c | 84 ++++++++++++++++++++++++++++-----------------
>  1 file changed, 53 insertions(+), 31 deletions(-)
> 
> diff --git a/src/conf/node_device_conf.c b/src/conf/node_device_conf.c
> index 85cfd8396..de346597a 100644
> --- a/src/conf/node_device_conf.c
> +++ b/src/conf/node_device_conf.c
> @@ -1286,76 +1286,100 @@ virPCIEDeviceInfoParseXML(xmlXPathContextPtr ctxt,
>  
>  
>  static int
> -virNodeDevPCICapabilityParseXML(xmlXPathContextPtr ctxt,
> -                                xmlNodePtr node,
> -                                virNodeDevCapPCIDevPtr pci_dev)
> +virNodeDevPCICapSRIOVParseXML(xmlXPathContextPtr ctxt,
> +                              xmlNodePtr node,
> +                              virNodeDevCapPCIDevPtr pci_dev,
> +                              unsigned int cap)
>  {

You can go even further and split this function into two separate functions
for "physical function" and "virtual function".

> +    int ret = -1;
>      char *maxFuncsStr = virXMLPropString(node, "maxCount");
> -    char *type = virXMLPropString(node, "type");
>      xmlNodePtr *addresses = NULL;
> -    xmlNodePtr orignode = ctxt->node;
> -    int ret = -1;
> -    size_t i = 0;
>  
> -    ctxt->node = node;
> -
> -    if (!type) {
> -        virReportError(VIR_ERR_XML_ERROR, "%s", _("Missing capability type"));
> -        goto out;
> -    }
> -
> -    if (STREQ(type, "phys_function")) {
> +    if (cap == VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION) {
>          xmlNodePtr address = virXPathNode("./address[1]", ctxt);
>  
>          if (VIR_ALLOC(pci_dev->physical_function) < 0)
> -            goto out;
> +            goto cleanup;
>  
>          if (!address) {
>              virReportError(VIR_ERR_XML_ERROR, "%s",
>                             _("Missing address in 'phys_function' capability"));
> -            goto out;
> +            goto cleanup;
>          }
>  
>          if (virPCIDeviceAddressParseXML(address,
>                                          pci_dev->physical_function) < 0)
> -            goto out;
> -
> -        pci_dev->flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
> -    } else if (STREQ(type, "virt_functions")) {
> +            goto cleanup;
> +    } else {
> +        size_t i;
>          int naddresses;
>  
>          if ((naddresses = virXPathNodeSet("./address", ctxt, &addresses)) < 0)
> -            goto out;
> +            goto cleanup;
>  
>          if (maxFuncsStr &&
>              virStrToLong_uip(maxFuncsStr, NULL, 10,
>                               &pci_dev->max_virtual_functions) < 0) {
>              virReportError(VIR_ERR_XML_ERROR, "%s",
>                             _("Malformed 'maxCount' parameter"));
> -            goto out;
> +            goto cleanup;
>          }
>  
>          if (VIR_ALLOC_N(pci_dev->virtual_functions, naddresses) < 0)
> -            goto out;
> +            goto cleanup;
>  
>          for (i = 0; i < naddresses; i++) {
>              virPCIDeviceAddressPtr addr = NULL;
>  
>              if (VIR_ALLOC(addr) < 0)
> -                goto out;
> +                goto cleanup;
>  
>              if (virPCIDeviceAddressParseXML(addresses[i], addr) < 0) {
>                  VIR_FREE(addr);
> -                goto out;
> +                goto cleanup;
>              }
>  
>              if (VIR_APPEND_ELEMENT(pci_dev->virtual_functions,
>                                     pci_dev->num_virtual_functions,
>                                     addr) < 0)
> -                goto out;
> +                goto cleanup;
>          }
> +    }
>  
> -        pci_dev->flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;
> +    pci_dev->flags |= cap;
> +    ret = 0;
> + cleanup:
> +    VIR_FREE(addresses);
> +    VIR_FREE(maxFuncsStr);
> +    return ret;
> +}
> +
> +
> +static int
> +virNodeDevPCICapabilityParseXML(xmlXPathContextPtr ctxt,
> +                                xmlNodePtr node,
> +                                virNodeDevCapPCIDevPtr pci_dev)
> +{
> +    char *type = virXMLPropString(node, "type");
> +    xmlNodePtr orignode = ctxt->node;
> +    unsigned int sriov_cap = 0;
> +    int ret = -1;
> +
> +    ctxt->node = node;
> +
> +    if (!type) {
> +        virReportError(VIR_ERR_XML_ERROR, "%s", _("Missing capability type"));
> +        goto cleanup;
> +    }
> +
> +    if (STREQ(type, "phys_function"))
> +        sriov_cap = VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
> +    else if (STREQ(type, "virt_functions"))
> +        sriov_cap = VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;
> +
> +    if (sriov_cap &&
> +        virNodeDevPCICapSRIOVParseXML(ctxt, node, pci_dev, sriov_cap) < 0) {
> +        goto cleanup;

If you drop the sriov_cap the code can be cleaner by simply passing the
VIR_NODE_DEV_CAP_FLAG_PCI_* flag directly as parameter and if you decide to
split the virNodeDevPCICapSRIOVParseXML() you will not need to pass it at all.)

Pavel

>      } else {
>          int hdrType = virPCIHeaderTypeFromString(type);
>  
> @@ -1364,9 +1388,7 @@ virNodeDevPCICapabilityParseXML(xmlXPathContextPtr ctxt,
>      }
>  
>      ret = 0;
> - out:
> -    VIR_FREE(addresses);
> -    VIR_FREE(maxFuncsStr);
> + cleanup:
>      VIR_FREE(type);
>      ctxt->node = orignode;
>      return ret;
> -- 
> 2.12.2
> 
> --
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