This patch adds cpuDataFormat and cpuDataParse APIs to be used in unit
tests for testing APIs that deal with virCPUData. In the x86 world, this
means we can now store/load arbitrary CPUID data in the test suite to
check correctness of CPU related APIs that could not be tested before.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can). But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).
Fix up offenders in src/cpu.
* src/cpu/cpu.h (cpuArchDecode, cpuArchEncode, cpuArchUpdate)
(cpuArchHasFeature, cpuDecode, cpuEncode, cpuUpdate)
(cpuHasFeature): Use intended type.
* src/conf/cpu_conf.h (virCPUDefCopyModel, virCPUDefCopy):
Likewise.
(virCPUDefParseXML): Drop const.
* src/cpu/cpu.c (cpuDecode, cpuEncode, cpuUpdate, cpuHasFeature):
Fix fallout.
* src/cpu/cpu_x86.c (x86ModelFromCPU, x86ModelSubtractCPU)
(x86DecodeCPUData, x86EncodePolicy, x86Encode, x86UpdateCustom)
(x86UpdateHostModel, x86Update, x86HasFeature): Likewise.
* src/cpu/cpu_s390.c (s390Decode): Likewise.
* src/cpu/cpu_arm.c (ArmDecode): Likewise.
* src/cpu/cpu_powerpc.c (ppcModelFromCPU, ppcCompute, ppcDecode)
(ppcUpdate): Likewise.
* src/conf/cpu_conf.c (virCPUDefCopyModel, virCPUDefCopy)
(virCPUDefParseXML): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
On Power platform, Power7+ can support Power7 guest.
It needs to define XML configuration to specify guest's CPU model.
For exmaple:
<cpu match='exact'>
<model>POWER7_v2.1</model>
<vendor>IBM</vendor>
</cpu>
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
The s390, ppc and arm CPU drivers never set the 'arch' field
in their impl of cpuArchNodeData. This leads to error messages
being reported from cpuDataFree later, due to trying to use
VIR_ARCH_NONE.
#0 virRaiseErrorFull (filename=filename@entry=0x76f94434 "cpu/cpu.c", funcname=funcname@entry=0x76f942dc <__FUNCTION__.18096> "cpuGetSubDriver", linenr=linenr@entry=58,
domain=domain@entry=31, code=code@entry=1, level=level@entry=VIR_ERR_ERROR, str1=0x76f70e18 "internal error: %s",
str2=str2@entry=0x7155f2ec "undefined hardware architecture", str3=str3@entry=0x0, int1=int1@entry=-1, int2=int2@entry=-1, fmt=0x76f70e18 "internal error: %s")
at util/virerror.c:646
#1 0x76e682ea in virReportErrorHelper (domcode=domcode@entry=31, errorcode=errorcode@entry=1, filename=0x76f94434 "cpu/cpu.c",
funcname=0x76f942dc <__FUNCTION__.18096> "cpuGetSubDriver", linenr=linenr@entry=58, fmt=0x76f7e7e4 "%s") at util/virerror.c:1292
#2 0x76ed82d4 in cpuGetSubDriver (arch=<optimized out>) at cpu/cpu.c:57
#3 cpuGetSubDriver (arch=VIR_ARCH_NONE) at cpu/cpu.c:51
#4 0x76ed8818 in cpuDataFree (data=data@entry=0x70c22d78) at cpu/cpu.c:216
#5 0x716aaec0 in virQEMUCapsInitCPU (arch=VIR_ARCH_ARMV7L, caps=0x70c29a08) at qemu/qemu_capabilities.c:867
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the virConnectBaselineCPU API does not expose the CPU features
that are part of the CPU's model. This patch adds a new flag,
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, that causes the API to explicitly
list all features that are part of that model.
Signed-off-by: Don Dugger <donald.d.dugger@intel.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Until now CPU features inherited from a specified CPU model could only
be overridden with 'disable' policy. With this patch, any explicitly
specified feature always overrides the same feature inherited from a CPU
model regardless on the specified policy.
The CPU in x86-exact-force-Haswell.xml would previously be incompatible
with x86-host-SandyBridge.xml CPU even though x86-host-SandyBridge.xml
provides all features required by x86-exact-force-Haswell.xml.
https://bugzilla.redhat.com/show_bug.cgi?id=799354
Until now, the "host-model" cpu mode couldn't be influenced. This patch
allows to use the <feature> elements to either enable or disable
specific CPU flags. This can be used to force flags that can be emulated
even if the host CPU doesn't support them.
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
The cpu_map.xml file is there to separate CPU model definitions from the
code. Having the only interesting data for PowerPC models only in the
source code. This patch moves this data to the XML file and removes the
hardcoded list completely.
PowerPC CPUs are either identical or incompatible and thus we just need
to look up the right model for given PVR without pretending we have
several candidates which we may choose from.
The function is also renamed as ppcDecode to match other functions in
PowerPC CPU driver.
Baseline API is supposed to return guest CPU definition that can be used
on any of the provided host CPUs. Since PowerPC CPUs are either
identical or incompatible, the API just needs to check that all provided
CPUs are identical. Previous implementation was completely bogus.
The function is also renamed as ppcBaseline to match other functions in
PowerPC CPU driver.
When ppcVendorLoad fails to parse the vendor element for whatever
reason, it is supposed to ignore it and return 0 rather than -1. The
patch also removes PowerPC vendor string from the XML as it is not
actually used for anything.
Make getting node CPU data for PowerPC unsupported on other
architectures. The function is also renamed as ppcNodeData to match
other functions in PowerPC CPU driver.
This makes code easier to read, by avoiding lines longer than
80 columns and removing the repetition from the callers.
* src/util/virstoragefile.c (qedGetHeaderUL, qedGetHeaderULL):
Delete in favor of more generic macros.
(qcow2GetBackingStoreFormat, qcowXGetBackingStore)
(qedGetBackingStore, virStorageFileMatchesVersion)
(virStorageFileGetMetadataInternal): Use new macros.
* src/cpu/cpu_x86.c (x86VendorLoad): Likewise.
Prior to the virArch changes, the CPU baseline method would
free the arch string in the returned CPU. Fix the regression
by setting arch to VIR_ARCH_NONE at the end
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The new model supports following features in addition to those supported
by SandyBridge:
fma, pcid, movbe, fsgsbase, bmi1, hle, avx2, smep, bmi2, erms, invpcid,
rtm
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Qemu has added some new feature flags. This patch adds them to libvirt.
The new features are for the cpuid function 0x7 that takes an argument
in the ecx register. Currently only 0x0 is used as the argument so I was
lazy and I just clear the registers to 0 before calling cpuid. In future
when there maybe will be some other possible arguments, we will need to
improve the cpu detection code to take this into account.
There are some descriptions not right in PowerPC CPU model driver.
This patch is to fix them.
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
Currently, the CPU model driver is not implemented for PowerPC.
Host's CPU information is needed to exposed to guests' XML file some
time.
This patch is to implement the callback functions of CPU model driver.
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
CPU version can be got by PVR on PowerPC. So this PVR is defined in
the CPU data in cpuData structure.
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
Adding CPU encoder/decoder for s390 to avoid runtime error messages.
Signed-off-by: Thang Pham <thang.pham@us.ibm.com>
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
This patch modifies the CPU comparrison function to report the
incompatibilities in more detail to ease identification of problems.
* src/cpu/cpu.h:
cpuGuestData(): Add argument to return detailed error message.
* src/cpu/cpu.c:
cpuGuestData(): Add passthrough for error argument.
* src/cpu/cpu_x86.c
x86FeatureNames(): Add function to convert a CPU definition to flag
names.
x86Compute(): - Add error message parameter
- Add macro for reporting detailed error messages.
- Improve error reporting.
- Simplify calculation of forbidden flags.
x86DataIteratorInit():
x86cpuidMatchAny(): Remove functions that are no longer needed.
* src/qemu/qemu_command.c:
qemuBuildCpuArgStr(): - Modify for new function prototype
- Add detailed error reports
- Change error code on incompatible processors
to VIR_ERR_CONFIG_UNSUPPORTED instead of
internal error
* tests/cputest.c:
cpuTestGuestData(): Modify for new function prototype
Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:
List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$'
Found files were modified with this command:
sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Then checked for nonsense.
The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Using inheritance, this patch cleans up the cpu_map.xml file and also
sorts all CPU features according to the feature and registry
values. Model features are sorted the same way as foeatures in the
specification.
Also few models that are related were organized together and parts of
the XML are marked with comments
AMD Bulldozer (or Opteron_G4 as called in QEMU) was added to the list
of cpu models, flags were taken from upstream qemu cpu specifications
and should be sorted by bit values (or first occurence in the feature
specification part of cpu_map.xml).
Based on QEMU upstream commit 885bb0369a4f0abe2c0185178f3cb347cb02cdf1.
We found few more AMD-specific features in cpu64-rhel* models that
made it impossible to start qemu guest on Intel host (with this
setting) even though qemu itself starts correctly with them.
This impacts one test, thus the fix in tests/cputestdata/.
In qemu there are 2 cpu models (cpu64-rhel5 and cpu64-rhel6) not
supported by libvirt. This patch adds the support with the flags
specifications from /usr/share/qemu-kvm/cpu-model/cpu-x86_64.conf
The only difference is that AMD-specific features are removed so
the processor type is not vendor-specific. Those features are either
emulated or ignored by qemu if host CPU doesn't support them.
Our HACKING discourages use of malloc and free, for at least
a couple of years now. But we weren't enforcing it, until now :)
For now, I've exempted python and tests, and will clean those up
in subsequent patches. Examples should be permanently exempt,
since anyone copying our examples won't have use of our
internal-only memory.h via libvirt_util.la.
* cfg.mk (sc_prohibit_raw_allocation): New rule.
(exclude_file_name_regexp--sc_prohibit_raw_allocation): and
exemptions.
* src/cpu/cpu.c (cpuDataFree): Avoid false positive.
* src/conf/network_conf.c (virNetworkDNSSrvDefParseXML): Fix
offenders.
* src/libxl/libxl_conf.c (libxlMakeDomBuildInfo, libxlMakeVfb)
(libxlMakeDeviceModelInfo): Likewise.
* src/rpc/virnetmessage.c (virNetMessageSaveError): Likewise.
* tools/virsh.c (_vshMalloc, _vshCalloc): Likewise.
Recently (or not so recently) QEMU added the kvm32 and kvm64
architectures, representing a least common denominator of all
hosts that can run KVM. Add them to the machine map.
Also, some features that TCG supports were added to qemu64.
Add them to the cpu_map.xml whenever KVM is guaranteed to support
those. We still have to leave some out, because they would not
be available to guests running on older hosts.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation for the patch to include Murmurhash3, which
introduces a virhashcode.h and virhashcode.c files, rename
the existing hash.h and hash.c to virhash.h and virhash.c
respectively.
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.
Add support for newly supported Intel cpu features. Newly supported
flags are: pclmuldq, dtes64, smx, fma, pdcm, movbe, xsave, osxsave and
avx. This adds support for Intel's Sandy Bridge platform.
To add support for running libvirt on PowerPC, a CPU driver for the
PowerPC platform must be added.
Most generic cpu driver routines such as CPU compare, decode, etc
are based on CPUID comparison and are not relevant for non-x86
platforms.
Here, we introduce stubs for relevant PowerPC routines invoked by libvirt.
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@au.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.
Commit 498d783 cleans up some of virtual file names for parsing strings
in memory. This patch cleans up (hopefuly) the rest forgotten by the
first patch.
This patch also changes all of the previously modified "filenames" to
valid URI's replacing spaces for underscores.
Changes to v1:
- Replace all spaces for underscores, so that the strings form valid
URI's
- Replace spaces in places changed by commit 498d783
These VIR_XXXX0 APIs make us confused, use the non-0-suffix APIs instead.
How do these coversions works? The magic is using the gcc extension of ##.
When __VA_ARGS__ is empty, "##" will swallow the "," in "fmt," to
avoid compile error.
example: origin after CPP
high_level_api("%d", a_int) low_level_api("%d", a_int)
high_level_api("a string") low_level_api("a string")
About 400 conversions.
8 special conversions:
VIR_XXXX0("") -> VIR_XXXX("msg") (avoid empty format) 2 conversions
VIR_XXXX0(string_literal_with_%) -> VIR_XXXX(%->%%) 0 conversions
VIR_XXXX0(non_string_literal) -> VIR_XXXX("%s", non_string_literal)
(for security) 6 conversions
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
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.
So far, CPUID data were stored in two different data structures. First
of them was a structure allowing direct access for CPUID data according
to function number and the second was a plain array of struct
cpuX86cpuid. This was a silly design which resulted in converting data
from one type to the other and back again or implementing similar
functionality for both data structures.
The patch leaves only the direct access structure. This makes the code
both smaller and more maintainable since operations on different objects
can use common low-level operations.
All 57 tests for cpu subsystem still pass after this rewrite.
When only some host CPUs given to cpuBaseline contain <vendor> element,
baseline CPU should not contain it. Otherwise the result would not be
compatible with the host CPUs without vendor. CPU vendors are still
taken into account when computing baseline CPU, it's just removed from
the result.
Recent CPU models were specified using invalid vendor element
<vendor>NAME</vendor>, which was silently ignored due to a bug in the
code which was parsing it.
This enables support for nested SVM using the regular CPU
model/features block. If the CPU model or features include
'svm', then the '-enable-nesting' flag will be added to the
QEMU command line. Latest out of tree patches for nested
'vmx', no longer require the '-enable-nesting' flag. They
instead just look at the cpu features. Several of the models
already include svm support, but QEMU was just masking out
the svm bit silently. So this will enable SVM on such
models
* src/qemu/qemu_conf.h: flag for -enable-nesting
* src/qemu/qemu_conf.c: Use -enable-nesting if VMX or SVM are in
the CPUID
* src/cpu/cpu.h, src/cpu/cpu.c: API to check for a named feature
* src/cpu/cpu_x86.c: x86 impl of feature check
* src/libvirt_private.syms: Add cpuHasFeature
* src/qemuhelptest.c: Add nesting flag where required
Some features provided by the recently added CPU models were mentioned
twice for each model. This was a result of automatic generation of the
XML from qemu's CPU configuration file without noticing this redundancy.
This patch fixes a couple of complaints from valgrind when tickling libvirtd with SIGHUP.
The first two files contain fixes for memory leaks. The 3rd one initializes an uninitialized variable. The 4th one is another memory leak.
When comparing a CPU without <model> element, such as
<cpu>
<topology sockets='1' cores='1' threads='1'/>
</cpu>
libvirt would happily crash without warning.
When a CPU to be compared with host CPU describes a host CPU instead of
a guest CPU, the result is incorrect. This is because instead of
treating additional features in host CPU description as required, they
were treated as if they were mentioned with all possible policies at the
same time.
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.
All features in the baseline CPU definition were always created with
policy='require' even though an arch driver returned them with different
policy settings.
Adds ability to provide a preferred CPU model for CPUID data decoding.
Such model would be considered as the best possible model (if it's
supported by hypervisor) regardless on number of features which have to
be added or removed for describing required CPU.
So far, when CPUID data were converted into CPU model and features, the
features can only be added to the model. As a result, when a guest asked
for something like "qemu64,-svm" it would get a qemu32 plus a bunch of
additional features instead.
This patch adds support for removing feature from the base model.
Selection algorithm remains the same: the best CPU model is the model
which requires lowest number of features to be added/removed from it.
When comparing a CPU to host CPU, the result would be
VIR_CPU_COMPARE_SUPERSET (or even VIR_CPU_COMPARE_INCOMPATIBLE if strict
match was required) even though the two CPUs were identical.
Useful mainly for migration. cpuUpdate changes guest CPU requirements in
the following way:
- match == "strict" || match == "exact"
- optional features which are supported by host CPU are changed into
required features
- optional features which are not supported by host CPU are disabled
- all other features remain untouched
- match == "minimum"
- match is changed into "exact"
- optional features and all features not mentioned in guest CPU
specification which are supported by host CPU become required
features
- other optional features are disabled
- all other features remain untouched
This ensures that no feature will suddenly disappear from the guest
after migration.
* src/cpu/cpu_x86.c (x86Decode): Don't dereference NULL when passed
a NULL "models" pointer, or when passed a nonzero "nmodels" value
and a corresponding NULL models[i].
All other libvirt functions use array first and then number of elements
in that array. Let's make cpuDecode follow this rule.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
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
When comparing x86 CPUs, features with 'disabled' policy were mistakenly
required to be supported by the host CPU.
Likewise, features with 'force' policy which were supported by host CPU
would make CPUs incompatible if 'strict' match was used by guest CPU.
This patch fixes both issues.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Current implementation of x86Decode() used for CPUID -> model+features
translation does not always select the closest CPU model. When walking
through all models from cpu_map.xml the function considers a new
candidate as a better choice than a previously selected candidate only
if the new one is a superset of the old one. In case the new candidate
is closer to host CPU but lacks some feature comparing to the old
candidate, the function does not choose well.
This patch changes the algorithm so that the closest model is always
selected. That is, the model which requires the lowest number of
additional features to describe host CPU.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Each driver supporting CPU selection must fill in host CPU capabilities.
When filling them, drivers for hypervisors running on the same node as
libvirtd can use cpuNodeData() to obtain raw CPU data. Other drivers,
such as VMware, need to implement their own way of getting such data.
Raw data can be decoded into virCPUDefPtr using cpuDecode() function.
When implementing virConnectCompareCPU(), a hypervisor driver can just
call cpuCompareXML() function with host CPU capabilities.
For each guest for which a driver supports selecting CPU models, it must
set the appropriate feature in guest's capabilities:
virCapabilitiesAddGuestFeature(guest, "cpuselection", 1, 0)
Actions needed when a domain is being created depend on whether the
hypervisor understands raw CPU data (currently CPUID for i686, x86_64
architectures) or symbolic names has to be used.
Typical use by hypervisors which prefer CPUID (such as VMware and Xen):
- convert guest CPU configuration from domain's XML into a set of raw
data structures each representing one of the feature policies:
cpuEncode(conn, architecture, guest_cpu_config,
&forced_data, &required_data, &optional_data,
&disabled_data, &forbidden_data)
- create a mask or whatever the hypervisor expects to see and pass it
to the hypervisor
Typical use by hypervisors with symbolic model names (such as QEMU):
- get raw CPU data for a computed guest CPU:
cpuGuestData(conn, host_cpu, guest_cpu_config, &data)
- decode raw data into virCPUDefPtr with a possible restriction on
allowed model names:
cpuDecode(conn, guest, data, n_allowed_models, allowed_models)
- pass guest->model and guest->features to the hypervisor
* src/cpu/cpu.c src/cpu/cpu.h src/cpu/cpu_generic.c
src/cpu/cpu_generic.h src/cpu/cpu_map.c src/cpu/cpu_map.h
src/cpu/cpu_x86.c src/cpu/cpu_x86.h src/cpu/cpu_x86_data.h
* configure.in: check for CPUID instruction
* src/Makefile.am: glue the new files in
* src/libvirt_private.syms: add new private symbols
* po/POTFILES.in: add new cpu files containing translatable strings
