Our current detection code uses just the number of CPU features which
need to be added/removed from the CPU model to fully describe the CPUID
data. The smallest number wins. But this may sometimes generate wrong
results as one can see from the fixed test cases. This patch modifies
the algorithm to prefer the CPU model with matching signature even if
this model results in a longer list of additional features.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The CPU model was implemented in QEMU by commit f6f949e929.
The change to i7-5600U is wrong since it's a 5th generation CPU, i.e.,
Broadwell rather than Skylake, but that's just the result of our CPU
detection code (which is fixed by the following commit).
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
As a side effect this changes the order of CPU features in XMLs
generated by libvirt, but that's not a big deal since the order there is
insignificant.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
For two reasons:
- 0x00000001 is very similar to 0x80000001, but 0x01 is visually
different
- 0x01 format is consistent with CPUID manual
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
CPUID instruction normally takes its parameter from EAX, but sometimes
ECX is used as an additional parameter. This patch prepares the x86 CPU
driver code for the new 'ecx_in' CPUID parameter.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The internal features are only used in explicit checks with
cpuHasFeature. Loading them into the CPU map is dangerous since the
features may accidentally be reported to users when decoding CPUID data.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
virCPUData and struct ppc64_model structures contained a pointer to
virCPUppc64Data, which was not very nice since the real data were
accessible by yet another level of pointers from virCPUppc64Data.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
virCPUData, virCPUx86Feature, and virCPUx86Model all contained a pointer
to virCPUx86Data, which was not very nice since the real CPUID data were
accessible by yet another pointer from virCPUx86Data. Moreover, using
virCPUx86Data directly will make static definitions of internal CPU
features a bit easier.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
CPUID instruction normally takes its parameter from EAX, but sometimes
ECX is used as an additional parameter. Let's rename 'function' to
'eax_in' in preparation for adding 'ecx_in'.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
A CPU data XML file already contains the architecture, let the parser
use it to detect which CPU driver should be used to parse the rest of
the file.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
When computing CPU data for a given guest CPU we should set CPUID vendor
bits appropriately so that we don't lose the vendor when transforming
CPU data back to XML description.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
cpu/cpu_ppc64.c: In function 'ppc64Compute':
cpu/cpu_ppc64.c:620:27: error: potential null pointer dereference [-Werror=null-dereference]
if (STRNEQ(guest_model->name, host_model->name)) {
~~~~~~~~~~~^~~
cpu/cpu_ppc64.c:620:9: note: in expansion of macro 'STRNEQ'
if (STRNEQ(guest_model->name, host_model->name)) {
^~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
All callers of cpuGetModels expect @models to be NULL-terminated. Once
both x86GetModels and ppc64GetModels were fixed to meet this
expectation, we can explicitly document it.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The architecture specific loaders are now called with a list of all
elements of a given type (rather than a single element at a time). This
avoids the need to reallocate the arrays in CPU maps for each element.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There's no reason for keeping the models in a linked list. Especially
when we know upfront the total number of models we are loading.
As a nice side effect, this fixes ppc64GetModels to always return a
NULL-terminated list of models.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There's no reason for keeping the vendors in a linked list. Especially
when we know upfront the total number of models we are loading.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There's no reason for keeping the features in a linked list. Especially
when we know upfront the total number of features we are loading.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There's no reason for keeping the vendors in a linked list. Especially
when we know upfront the total number of models we are loading.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There's no reason for keeping the models in a linked list. Especially
when we know upfront the total number of models we are loading.
As a nice side effect, this fixes x86GetModels to always return a
NULL-terminated list of models.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
When searching for the best CPU model for CPUID data we can easily
ignore models with non-matching vendor before spending time on CPUID
data to virCPUDef conversion.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Splitting the comparison into a separate function makes the code cleaner
and easier to update in the future.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Usage of this keyword in front of function declaration that is exported via a
header file is unnecessary, since internally, this has been the default for most
compilers for quite some time.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Commit 7068b56c introduced several hyperv features. Not all hyperv
features are supported by old enough kernels and we shouldn't allow to
start a guest if kernel doesn't support any of the hyperv feature.
There is one exception, for backward compatibility we cannot error out
if one of the RELAXED, VAPIC or SPINLOCKS isn't supported, for the same
reason we ignore invtsc, to not break restoring saved domains with older
libvirt.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
While the check is appropriate for eg. the x86 and generic drivers,
there are some valid ppc64 guest configurations where the CPU
model is supposed to be NULL.
Moving this check from the generic code to the drivers makes it
possible to accomodate both use cases.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1251927
Not all combinations of host CPU models and compatibility modes
are valid, so we need to make sure we don't try to do something
that QEMU will reject.
Moreover, we need to apply a different logic to guests using
host-model and host-passthrough modes when testing them for host
compatibility.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1251927
If a guest CPU is defined using
<cpu mode='host-model'/>
the <model> sub-element will contain the compatibility mode to use.
That means we can't just copy the host CPU model on cpuUpdate(),
otherwise we'll overwrite that information and migration of such
guests will fail.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1251927
Unlike what happens on x86, on ppc64 you can't mix and match CPU
features to obtain the guest CPU you want regardless of the host
CPU, so the concept of model fallback doesn't apply.
Make sure CPU definitions emitted by the driver, eg. as output of
the cpuBaseline() and cpuUpdate() calls, reflect this fact.
