Bug 1592737

The cpu-compare and cpu-baseline virsh commands were made user friendly so
that the user can pass various XMLs generated by other libvirt commands to
them. The cpu-compare command takes a single XML document, while cpu-baseline
accepts several concatenated XMLs. Thus there were two separate pieces of code
dealing with the same. When I was adding the hypervisor variants of these
commands I had to add support for parsing one more type of XML document
generated by libvirt. While doing that, I merged the code for all the commands
to reduce duplication. And because libvirt never produces the <?xml ?>
declaration, the code does not work correctly when it sees <?xml ?>.

I will try to look at this and come up with a fix which would not be too
hacky. However, I don't see this as a big priority. Only virsh is affected,
calling libvirt API (even using some of the bindings) directly would just
work. And all avocado tests should really be rewritten to use libvirt's python
bindings.

Patch sent upstream for review:
https://www.redhat.com/archives/libvir-list/2018-November/msg00838.html

Fixed upstream by

commit fcd1c865e168bdb9763b19e790c15e80aa29be66
Refs: v4.10.0-rc1-5-gfcd1c865e1
Author:     Jiri Denemark <jdenemar>
AuthorDate: Thu Nov 22 16:28:56 2018 +0100
Commit:     Jiri Denemark <jdenemar>
CommitDate: Thu Nov 29 11:46:42 2018 +0100

    virsh: Strip XML declaration when extracting CPU XMLs

    Since commit v4.3.0-336-gc84726fbdd all
    {hypervisor-,}cpu-{baseline,compare} commands use a generic
    vshExtractCPUDefXMLs helper for extracting individual CPU definitions
    from the provided input file. The helper wraps the input file in a
    <container> element so that several independent elements can be easily
    parsed from the file. This works fine except when the file starts with
    XML declaration (<?xml version="1.0" ... ?>) because the XML declaration
    cannot be put inside any element. In fact it has to be at the very
    beginning of the XML document without any preceding white space
    characters. We can just simply skip the XML declaration.

    https://bugzilla.redhat.com/show_bug.cgi?id=1592737

    Signed-off-by: Jiri Denemark <jdenemar>
    Reviewed-by: Ján Tomko <jtomko>

*** Bug 1659045 has been marked as a duplicate of this bug. ***

------- Comment From satheera.com 2018-12-13 08:08 EDT-------
Fixed by upstream commit

Verified on libvirt-4.5.0-12.el7.x86_64.

Version:
kernel-3.10.0-1036.el7.x86_64
libvirt-4.5.0-12.el7.x86_64
qemu-kvm-rhev-2.12.0-25.el7.x86_64

Steps:
1. Prepare 2 intel/AMD hosts, and get the output of 'virsh capabilities' on each host
# virsh capabilities >> cap_1.xml

# virsh capabilities >> cap_2.xml

# cat cap_1.xml >> cap.xml 

# cat cap_2.xml >> cap.xml

2. Test {hypervisor-,}cpu-{baseline,compare} commands with the 'cpu.xml' above
# virsh hypervisor-cpu-baseline cap.xml 
<cpu mode='custom' match='exact'>
  <model fallback='forbid'>Penryn</model>
  <vendor>Intel</vendor>
  <feature policy='require' name='vme'/>
  <feature policy='require' name='ds'/>
  <feature policy='require' name='acpi'/>
  <feature policy='require' name='ss'/>
  <feature policy='require' name='ht'/>
  <feature policy='require' name='tm'/>
  <feature policy='require' name='pbe'/>
  <feature policy='require' name='dtes64'/>
  <feature policy='require' name='monitor'/>
  <feature policy='require' name='ds_cpl'/>
  <feature policy='require' name='vmx'/>
  <feature policy='require' name='tm2'/>
  <feature policy='require' name='xtpr'/>
  <feature policy='require' name='pdcm'/>
  <feature policy='require' name='xsave'/>
  <feature policy='require' name='osxsave'/>
</cpu>

# virsh hypervisor-cpu-compare cap.xml 
CPU described in cap.xml is incompatible with the CPU provided by hypervisor on the host

# virsh cpu-baseline cap.xml 
<cpu mode='custom' match='exact'>
  <model fallback='allow'>Penryn</model>
  <vendor>Intel</vendor>
  <feature policy='require' name='vme'/>
  <feature policy='require' name='ds'/>
  <feature policy='require' name='acpi'/>
  <feature policy='require' name='ss'/>
  <feature policy='require' name='ht'/>
  <feature policy='require' name='tm'/>
  <feature policy='require' name='pbe'/>
  <feature policy='require' name='dtes64'/>
  <feature policy='require' name='monitor'/>
  <feature policy='require' name='ds_cpl'/>
  <feature policy='require' name='vmx'/>
  <feature policy='require' name='tm2'/>
  <feature policy='require' name='xtpr'/>
  <feature policy='require' name='pdcm'/>
  <feature policy='require' name='xsave'/>
  <feature policy='require' name='osxsave'/>
</cpu>

# virsh cpu-compare cap.xml 
CPU described in cap.xml is incompatible with host CPU

All the test results are as expected, move this bug to be verified.

In step-1, Add the <?xml version='1.0' encoding='UTF-8'?> XMl declaration at the first of each file.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2019:2294