This update for xen fixes several issues.
These security issues were fixed:
This non-security issue was fixed:
{
    "binaries": [
        {
            "xen-doc-html": "4.2.5_21-30.1",
            "xen": "4.2.5_21-30.1",
            "xen-kmp-pae": "4.2.5_21_3.0.101_0.47.90-30.1",
            "xen-kmp-default": "4.2.5_21_3.0.101_0.47.90-30.1",
            "xen-libs-32bit": "4.2.5_21-30.1",
            "xen-tools-domU": "4.2.5_21-30.1",
            "xen-libs": "4.2.5_21-30.1",
            "xen-tools": "4.2.5_21-30.1",
            "xen-doc-pdf": "4.2.5_21-30.1"
        }
    ]
}{
    "binaries": [
        {
            "xen-doc-html": "4.2.5_21-30.1",
            "xen": "4.2.5_21-30.1",
            "xen-kmp-default": "4.2.5_21_3.0.101_0.47.90-30.1",
            "xen-libs-32bit": "4.2.5_21-30.1",
            "xen-tools-domU": "4.2.5_21-30.1",
            "xen-libs": "4.2.5_21-30.1",
            "xen-tools": "4.2.5_21-30.1",
            "xen-doc-pdf": "4.2.5_21-30.1"
        }
    ]
}{
    "binaries": [
        {
            "xen-doc-html": "4.2.5_21-30.1",
            "xen": "4.2.5_21-30.1",
            "xen-kmp-default": "4.2.5_21_3.0.101_0.47.90-30.1",
            "xen-libs-32bit": "4.2.5_21-30.1",
            "xen-tools-domU": "4.2.5_21-30.1",
            "xen-libs": "4.2.5_21-30.1",
            "xen-tools": "4.2.5_21-30.1",
            "xen-doc-pdf": "4.2.5_21-30.1"
        }
    ]
}{
    "binaries": [
        {
            "xen-doc-html": "4.2.5_21-30.1",
            "xen": "4.2.5_21-30.1",
            "xen-kmp-default": "4.2.5_21_3.0.101_0.47.90-30.1",
            "xen-libs-32bit": "4.2.5_21-30.1",
            "xen-tools-domU": "4.2.5_21-30.1",
            "xen-libs": "4.2.5_21-30.1",
            "xen-tools": "4.2.5_21-30.1",
            "xen-doc-pdf": "4.2.5_21-30.1"
        }
    ]
}