[v1] qemu: don't raise error upon interface update without <frames/> for <rx/> in coalesce

[PATCH] qemu: don't raise error upon interface update without <frames/> for <rx/> in coalesce

Posted by Kristina Hanicova 3 years, 1 month ago

With this, incomplete XML without <frames/> for <rx/> in coalesce
won't raise error as before. It will leave the coalesce parameter
empty, thanks to passing it as a parameter and return an integer
to indicate error state - previously it returned pointer (or NULL
for both error and incomplete XML).

The code went through some refactoring:
* change of a condition
* addition of a parameter
* change of order, that allowed removal of VIR_FREE
* removal of redundant labels and variables

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1535930
Signed-off-by: Kristina Hanicova <khanicov@redhat.com>
---
 src/conf/domain_conf.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index b731744f04..798594f520 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -7516,11 +7516,11 @@ virDomainNetIPInfoParseXML(const char *source,
 }
 
 
-static virNetDevCoalescePtr
+static int
 virDomainNetDefCoalesceParseXML(xmlNodePtr node,
-                                xmlXPathContextPtr ctxt)
+                                xmlXPathContextPtr ctxt,
+                                virNetDevCoalescePtr *coalesce)
 {
-    virNetDevCoalescePtr ret = NULL;
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
     unsigned long long tmp = 0;
     g_autofree char *str = NULL;
@@ -7529,15 +7529,13 @@ virDomainNetDefCoalesceParseXML(xmlNodePtr node,
 
     str = virXPathString("string(./rx/frames/@max)", ctxt);
     if (!str)
-        return NULL;
-
-    ret = g_new0(virNetDevCoalesce, 1);
+        return 0;
 
     if (virStrToLong_ullp(str, NULL, 10, &tmp) < 0) {
         virReportError(VIR_ERR_XML_DETAIL,
                        _("cannot parse value '%s' for coalesce parameter"),
                        str);
-        goto error;
+        return -1;
     }
 
     if (tmp > UINT32_MAX) {
@@ -7545,15 +7543,13 @@ virDomainNetDefCoalesceParseXML(xmlNodePtr node,
                        _("value '%llu' is too big for coalesce "
                          "parameter, maximum is '%lu'"),
                        tmp, (unsigned long) UINT32_MAX);
-        goto error;
+        return -1;
     }
-    ret->rx_max_coalesced_frames = tmp;
 
-    return ret;
+    *coalesce = g_new0(virNetDevCoalesce, 1);
+    (*coalesce)->rx_max_coalesced_frames = tmp;
 
- error:
-    VIR_FREE(ret);
-    return NULL;
+    return 0;
 }
 
 static void
@@ -11517,8 +11513,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
 
     node = virXPathNode("./coalesce", ctxt);
     if (node) {
-        def->coalesce = virDomainNetDefCoalesceParseXML(node, ctxt);
-        if (!def->coalesce)
+        if (virDomainNetDefCoalesceParseXML(node, ctxt, &def->coalesce) < 0)
             goto error;
     }
 
-- 
2.29.2

Re: [PATCH] qemu: don't raise error upon interface update without <frames/> for <rx/> in coalesce

Posted by Martin Kletzander 3 years, 1 month ago

On Thu, Mar 04, 2021 at 01:58:17PM +0100, Kristina Hanicova wrote:
>With this, incomplete XML without <frames/> for <rx/> in coalesce
>won't raise error as before. It will leave the coalesce parameter
>empty, thanks to passing it as a parameter and return an integer
>to indicate error state - previously it returned pointer (or NULL
>for both error and incomplete XML).
>
>The code went through some refactoring:
>* change of a condition
>* addition of a parameter
>* change of order, that allowed removal of VIR_FREE
>* removal of redundant labels and variables
>
>Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1535930
>Signed-off-by: Kristina Hanicova <khanicov@redhat.com>
>---
> src/conf/domain_conf.c | 25 ++++++++++---------------
> 1 file changed, 10 insertions(+), 15 deletions(-)
>

The code is good, but it could use some test(s).  I guess you have couple of
options here:

  - just show that parsing it does nothing in simple qemuxml2xmltest

  - make sure that this makes it possible to remove the coalesce settings in
    qemuhotplugtest.  This might not be the case and it might result in more
    patches because, honestly, I am not 100% sure how to handle removal of
    coalesce parameters versus not touching them on update.

Since this is not a critical thing to do, I'll leave that up to you to decide
how to approach this ;)

Thanks,
Martin