The reworked API is now called virCPUUpdate and it should change the
provided CPU definition into a one which can be consumed by the QEMU
command line builder:
- host-passthrough remains unchanged
- host-model is turned into custom CPU with a model and features
copied from host
- custom CPU with minimum match is converted similarly to host-model
- optional features are updated according to host's CPU
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
x86ModelFromCPU is used to provide CPUID data for features matching
@policy. This patch allows callers to set @policy to -1 to get combined
CPUID for all CPU features (including those implicitly provided a CPU
model) specified in CPU def.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
When starting a guest and copying host vendor cpuid to the guest
cpu, libvirtd would crash if the host cpu contained a NULL vendor
field. Avoid the crash by checking for a valid vendor in the host
cpu before copying the cpuid to the guest cpu.
For completeness, here is a backtrace from the crash
(gdb) bt
f0 0x00007ffff739bf33 in x86DataCpuid (cpuid=0x8, cpuid=0x8,
data=data@entry=0x7fffb800ee78) at cpu/cpu_x86.c:287
f1 virCPUx86DataAddCPUID (data=data@entry=0x7fffb800ee78, cpuid=0x8)
at cpu/cpu_x86.c:355
f2 0x00007ffff739ef47 in x86Compute (host=<optimized out>, cpu=0x7fffb8000cc0,
guest=0x7fffecca7348, message=<optimized out>) at cpu/cpu_x86.c:1580
f3 0x00007fffd2b38e53 in qemuBuildCpuModelArgStr (migrating=false,
hasHwVirt=<synthetic pointer>, qemuCaps=0x7fffb8001040, buf=0x7fffecca7360,
def=0x7fffc400ce20, driver=0x1c) at qemu/qemu_command.c:6283
f4 qemuBuildCpuCommandLine (cmd=cmd@entry=0x7fffb8002f60,
driver=driver@entry=0x7fffc80882c0, def=def@entry=0x7fffc400ce20,
qemuCaps=qemuCaps@entry=0x7fffb8001040, migrating=<optimized out>)
at qemu/qemu_command.c:6445
(gdb) f2
(gdb) p *host_model
$23 = {name = 0x7fffb800ec50 "qemu64", vendor = 0x0, signature = 0, data = {
len = 2, data = 0x7fffb800e720}}
Since the introduction of CMT features (commit v1.3.5-461-gf294b83)
starting a domain with host-model CPU on a host which supports CMT fails
because QEMU complains about unknown 'cmt' feature:
qemu-system-x86_64: CPU feature cmt not found
https://bugzilla.redhat.com/show_bug.cgi?id=1355857
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
By removing a non-migratable feature in a for loop we would fail to drop
every second non-migratable feature if the features array contained
several of them in a row.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
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>
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, 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>
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 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>
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
Commit 86a15a25 introduced a new cpu driver API 'getModels'. Public API
allow you to pass NULL for models to get only number of existing models.
However the new code will crash with segfault so we have to count with
the possibility that the user wants only the number.
There is also difference in order of the models gathered by this new API
as the old approach was inserting the elements to the end of the array
so we should use 'VIR_APPEND_ELEMENT'.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
For Intel and PowerPC the implementation is calling a cpu driver
function across driver layers (i.e. from qemu driver directly to cpu
driver).
The correct behavior is to use libvirt API functionality to perform such
a inter-driver call.
This patch introduces a new cpu driver API function getModels() to
retrieve the cpu models. The currect implementation to process the
cpu_map XML content is transferred to the INTEL and PowerPC cpu driver
specific API functions.
Additionally processing the cpu_map XML file is not safe due to the fact
that the cpu map does not exist for all architectures. Therefore it is
better to encapsulate the processing in the architecture specific cpu
drivers.
Signed-off-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Commit de0aeaf filtered them out from the host-model features,
to allow host-model to be migratable by default.
Even though they are not passed to QEMU for host-passthrough,
(and not enabled by default) filter them out too
so the user does not think the domain has them.
https://bugzilla.redhat.com/show_bug.cgi?id=1147584
Commit fba6bc4 introduced support for the 'invtsc' feature,
which blocks migration. We should not include it in the
host-model CPU by default, because it's intended to be used
with migration.
https://bugzilla.redhat.com/show_bug.cgi?id=1138221
