Tell the user what CPU mode value is wrong

VIR_DOMAIN_XML_UPDATE_CPU flag for virDomainGetXMLDesc may be used to
get updated custom mode guest CPU definition in case it depends on host
CPU. This patch implements the same behavior for host-model and
host-passthrough CPU modes.

The mode can be either of "custom" (default), "host-model",
"host-passthrough". The semantics of each mode is described in the
following examples:

- guest CPU is a default model with specified topology:
    <cpu>
      <topology sockets='1' cores='2' threads='1'/>
    </cpu>

- guest CPU matches selected model:
    <cpu mode='custom' match='exact'>
      <model>core2duo</model>
    </cpu>

- guest CPU should be a copy of host CPU as advertised by capabilities
  XML (this is a short cut for manually copying host CPU specification
  from capabilities to domain XML):
    <cpu mode='host-model'/>

  In case a hypervisor does not support the exact host model, libvirt
  automatically falls back to a closest supported CPU model and
  removes/adds features to match host. This behavior can be disabled by
    <cpu mode='host-model'>
      <model fallback='forbid'/>
    </cpu>

- the same as previous returned by virDomainGetXMLDesc with
  VIR_DOMAIN_XML_UPDATE_CPU flag:
    <cpu mode='host-model' match='exact'>
      <model fallback='allow'>Penryn</model>       --+
      <vendor>Intel</vendor>                         |
      <topology sockets='2' cores='4' threads='1'/>  + copied from
      <feature policy='require' name='dca'/>         | capabilities XML
      <feature policy='require' name='xtpr'/>        |
      ...                                          --+
    </cpu>

- guest CPU should be exactly the same as host CPU even in the aspects
  libvirt doesn't model (such domain cannot be migrated unless both
  hosts contain exactly the same CPUs):
    <cpu mode='host-passthrough'/>

- the same as previous returned by virDomainGetXMLDesc with
  VIR_DOMAIN_XML_UPDATE_CPU flag:
    <cpu mode='host-passthrough' match='minimal'>
      <model>Penryn</model>                        --+ copied from caps
      <vendor>Intel</vendor>                         | XML but doesn't
      <topology sockets='2' cores='4' threads='1'/>  | describe all
      <feature policy='require' name='dca'/>         | aspects of the
      <feature policy='require' name='xtpr'/>        | actual guest CPU
      ...                                          --+
    </cpu>

In case a hypervisor doesn't support the exact CPU model requested by a
domain XML, we automatically fallback to a closest CPU model the
hypervisor supports (and make sure we add/remove any additional features
if needed). This patch adds 'fallback' attribute to model element, which
can be used to disable this automatic fallback.

As a result of it, guest NUMA topology would be lost during migration.

None of the callers cared if str was updated to point to the next
byte after the parsed cpuset; simplifying this results in quite
a few code simplifications.  Additionally, virCPUDefParseXML was
strdup()'ing a malloc()'d string; avoiding a memory copy resulted
in less code.

* src/conf/domain_conf.h (virDomainCpuSetParse): Alter signature.
* src/conf/domain_conf.c (virDomainCpuSetParse): Don't modify str.
(virDomainVcpuPinDefParseXML, virDomainDefParseXML): Adjust
callers.
* src/conf/cpu_conf.c (virCPUDefParseXML): Likewise.
* src/xen/xend_internal.c (sexpr_to_xend_topology): Likewise.
* src/xen/xm_internal.c (xenXMDomainPinVcpu): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxpr): Likewise.
* src/xenxs/xen_xm.c (xenParseXM): Likewise.

Add routines to generate -numa QEMU command line option based on
<numa> ... </numa> XML specifications.
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>

This patch adds XML definitions for guest NUMA specification and contains
routines to parse the same. The guest NUMA specification looks like this:

<cpu>
        ...
        <topology sockets='2' cores='4' threads='2'/>
        <numa>
                <cell cpus='0-7' memory='512000'/>
                <cell cpus='8-15' memory='512000'/>
        </numa>
        ...
</cpu>
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>

Auto-indent makes life a bit easier; this patch also drops unused
arguments and replaces a misspelled flag name with two entry points
instead, so that callers don't have to worry about how much spacing
is present when embedding cpu elements.

* src/conf/cpu_conf.h (virCPUFormatFlags): Delete.
(virCPUDefFormat): Drop unused argument.
(virCPUDefFormatBuf): Alter signature.
(virCPUDefFormatBufFull): New prototype.
* src/conf/cpu_conf.c (virCPUDefFormatBuf): Split...
(virCPUDefFormatBufFull): ...into new function.
(virCPUDefFormat): Adjust caller.
* src/conf/domain_conf.c (virDomainDefFormatInternal): Likewise.
* src/conf/capabilities.c (virCapabilitiesFormatXML): Likewise.
* src/cpu/cpu.c (cpuBaselineXML): Likewise.
* tests/cputest.c (cpuTestCompareXML): Likewise.

* src/conf/cpu_conf.h (virCPUDefFormat, virCPUDefFormatBuf):
Change flags type.
* src/conf/cpu_conf.c (virCPUDefFormat, virCPUDefFormatBuf):
Likewise.
* src/conf/storage_conf.c (_virStoragePoolOptions): Likewise.
* src/datatypes.h (_virConnect, _virStream): Likewise.

To allow a client app to pass in custom XML during migration
of a guest it is neccessary to ensure the guest ABI remains
unchanged. The virDomainDefCheckABIStablity method accepts
two virDomainDefPtr structs and compares everything in them
that could impact the guest machine ABI

* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/libvirt_private.syms: Add virDomainDefCheckABIStablity
* src/conf/cpu_conf.c, src/conf/cpu_conf.h: Add virCPUDefIsEqual
* src/util/sysinfo.c, src/util/sysinfo.h: Add virSysinfoIsEqual

We already have virAsprintf, so picking a similar name helps for
seeing a similar purpose.  Furthermore, the prefix V before printf
generally implies 'va_list', even though this variant was '...', and
the old name got in the way of adding a new va_list version.

global rename performed with:

$ git grep -l virBufferVSprintf \
  | xargs -L1 sed -i 's/virBufferVSprintf/virBufferAsprintf/g'

then revert the changes in ChangeLog-old.

And from all related macros and functions.

* src/conf/capabilities.h (_virCaps, _virCapsHost, _virCapsGuest)
(_virCapsGuestArch): Add additional fields.
* src/conf/cpu_conf.h (_virCPUDef): Likewise.
* src/conf/capabilities.c (virCapabilitiesFormatXML): Reflect
updated type.
(virCapabilitiesAddGuest, virCapabilitiesAddHostFeature)
(virCapabilitiesAddHostMigrateTransport)
(virCapabilitiesAddHostNUMACell, virCapabilitiesAddGuestFeature)
(virCapabilitiesAddGuestDomain): Use new array APIs.
* src/conf/cpu_conf.c (virCPUDefAddFeature, virCPUDefCopy)
(virCPUDefParseXML): Likewise.
* tests/testutilsqemu.c (testQemuCapsInit): Adjust test.

Suggested by danpb, as it's not up-to-date anymore and
lacks many functions that were added to libvirtd.

To enable the CPU XML from the capabilities to be pasted directly
into the guest XML with no editing, pick a sensible default for
match and feature policy. The CPU match will be exact and the
feature policy will be require. This should ensure safety for
migration and give DWIM semantics for users

* src/conf/cpu_conf.c: Default to exact match and require policy
* docs/formatdomain.html.in: Document new defaults

When autodetecting whether XML describes guest or host CPU, the presence
of <arch> element is checked. If it's present, we treat the XML as host
CPU definition. Which is right, since guest CPU definitions do not
contain <arch> element. However, if at the same time the root <cpu>
element contains `match' attribute, we would silently ignore it and
still treat the XML as host CPU. We should rather refuse such invalid
XML.

By specifying <vendor> element in CPU requirements a guest can be
restricted to run only on CPUs by a given vendor. Host CPU vendor is
also specified in capabilities XML.

The vendor is checked when migrating a guest but it's not forced, i.e.,
guests configured without <vendor> element can be freely migrated.

Received report of user crashing libvirtd with

virsh capabilities > capabilities.xml
virsh cpu-compare capabilities.xml

While user has been informed about proper usage of cpu-compare,
segfaulting libvirt should be avoided.

Do not parse CPU definition in virCPUDefParseXML() if XML is not
a 'cpu' node.

Prior to this patch, there was an inconsistent mix between GNU and C99.

For consistency, and potential portability to other compilers, stick
with the C99 vararg macro syntax.

* src/conf/cpu_conf.c (virCPUReportError): Use C99 rather than GNU
  vararg macro syntax.
* src/conf/domain_conf.c (virDomainReportError): Likewise.
* src/conf/domain_event.c (eventReportError): Likewise.
* src/conf/interface_conf.c (virInterfaceReportError): Likewise.
* src/conf/network_conf.c (virNetworkReportError): Likewise.
* src/conf/node_device_conf.h (virNodeDeviceReportError): Likewise.
* src/conf/secret_conf.h (virSecretReportError): Likewise.
* src/conf/storage_conf.h (virStorageReportError): Likewise.
* src/esx/esx_device_monitor.c (ESX_ERROR): Use C99 rather than
  GNU vararg macro syntax.
* src/esx/esx_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_interface_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_network_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_secret_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_storage_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_util.c (ESX_ERROR): Likewise.
* src/esx/esx_vi.c (ESX_VI_ERROR): Likewise.
* src/esx/esx_vi_methods.c (ESX_VI_ERROR): Likewise.
* src/esx/esx_vi_types.c (ESX_VI_ERROR): Likewise.
* src/esx/esx_vmx.c (ESX_ERROR): Likewise.
* src/util/hostusb.c (usbReportError): Use C99 rather than GNU
  vararg macro syntax.
* src/util/json.c (virJSONError): Likewise.
* src/util/macvtap.c (ReportError): Likewise.
* src/util/pci.c (pciReportError): Likewise.
* src/util/stats_linux.c (virStatsError): Likewise.
* src/util/util.c (virUtilError): Likewise.
* src/util/xml.c (virXMLError): Likewise.
* src/xen/proxy_internal.c (virProxyError): Use C99 rather than
  GNU vararg macro syntax.
* src/xen/sexpr.c (virSexprError): Likewise.
* src/xen/xen_driver.c (xenUnifiedError): Likewise.
* src/xen/xen_hypervisor.c (virXenError): Likewise.
* src/xen/xen_inotify.c (virXenInotifyError): Likewise.
* src/xen/xend_internal.c (virXendError): Likewise.
* src/xen/xm_internal.c (xenXMError): Likewise.
* src/xen/xs_internal.c (virXenStoreError): Likewise.
* src/cpu/cpu.h (virCPUReportError): Use C99 rather than GNU
  vararg macro syntax.
* src/datatypes.c (virLibConnError): Likewise.
* src/interface/netcf_driver.c (interfaceReportError): Likewise.
* src/libvirt.c (virLibStreamError): Likewise.
* src/lxc/lxc_conf.h (lxcError): Likewise.
* src/network/bridge_driver.c (networkReportError): Likewise.
* src/nodeinfo.c (nodeReportError): Likewise.
* src/opennebula/one_conf.h (oneError): Likewise.
* src/openvz/openvz_conf.h (openvzError): Likewise.
* src/phyp/phyp_driver.c (PHYP_ERROR): Likewise.
* src/qemu/qemu_conf.h (qemuReportError): Likewise.
* src/remote/remote_driver.c (errorf): Likewise.
* src/security/security_driver.h (virSecurityReportError): Likewise.
* src/test/test_driver.c (testError): Likewise.
* src/uml/uml_conf.h (umlReportError): Likewise.
* src/vbox/vbox_driver.c (vboxError): Likewise.
* src/vbox/vbox_tmpl.c (vboxError): Likewise.

The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in cpu_conf.{h,c} and update all callers to
match

It was used for error reporting only.

Currently CPU topology may only be specified together with CPU model:
    <cpu match='exact'>
        <model>name</model>
        <topology sockets='1' cores='2' threads='3'/>
    </cpu>

This patch allows for CPU topology specification without the need for
also specifying CPU model:
    <cpu>
        <topology sockets='1' cores='2' threads='3'/>
    </cpu>

'match' attribute and 'model' element are made optional with the
restriction that 'match' attribute has to be set when 'model' is
present.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

* po/POTFILES.in: adds src/conf/cpu_conf.c in teh set of files with
  translatable content
* src/conf/cpu_conf.c: remove an unused include

* include/libvirt/virterror.h src/util/virterror.c: add new domain
  VIR_FROM_CPU for errors
* src/conf/cpu_conf.c src/conf/cpu_conf.h: new parsing module
* src/Makefile.am proxy/Makefile.am: include new files
* src/conf/capabilities.[ch] src/conf/domain_conf.[ch]: reference
  new code
* src/libvirt_private.syms: private export of new entry points