The logic applied in the ppc64 case isn't quite correct, as the
interpretation of maximum mode depends on whether hardware virt
is used or not. This is information the CPU driver doesn't have.
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
For backward compatibility with older versions of libvirt CPU models in
our CPU map are mostly immutable. We only changed them in a few specific
cases after showing it was safe. Sometimes QEMU developers realize a
specific feature should not be part of a particular (or any) CPU model
because it can never be enabled automatically without further
configuration. But we couldn't follow them because doing so would break
migration to older libvirt.
If QEMU drops feature F from CPU model M because F could not be enabled
automatically anyway, asking for M would never enable F. Even with older
QEMU versions. Naively removing F from libvirt's definition of M would
seem to work nicely on a single host. Libvirt would consider M to be
compatible with hosts CPU that do not support F. However, trying to
migrate domains using M without explicitly enabling or disabling F could
fail, because older libvirt would think F was enabled (it is part of M
there), but QEMU reports it as disabled once started.
Thus we can remove such feature from a libvirt's CPU model, but we have
to make sure any CPU definition using the affected model will always
explicitly mention the state of the removed feature.
https://bugzilla.redhat.com/show_bug.cgi?id=1798004
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
The patch adds a new attribute for the 'feature' element in CPU model
specification to indicate that a given feature was removed from a CPU
model. In other words, older versions of libvirt would consider such
feature to be included in the CPU model.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
This is just a preparation for adding new functionality to
virCPUx86Update.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
Until now, the function returned immediately when the guest CPU
definition did not use optional features or minimum match. Clearly,
there's nothing to be updated according to the host CPU in this case,
but the arch specific code may still want to do some compatibility
updates based on the model and features used in the guest CPU
definition.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
Note the use of g_clear_pointer(..., g_free) in ppc64DataClear and virCPUx86Baseline.
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Non-x86 archs does not have a 'microcode' version like x86. This is
covered already inside the function - just return 0 if no microcode
is found. Regardless of that, a read of /proc/cpuinfo is always made.
Each read will invoke the kernel to fill in the CPU details every time.
Now let's consider a non-x86 host, like a Power 9 server with 128 CPUs.
Each /proc/cpuinfo read will need to fetch data for each CPU and it
won't even matter because we know beforehand that PowerPC chips don't
have microcode information.
We can do better for non-x86 hosts by skipping this process entirely.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Since the macro no longer includes the 'ignore_value'
statement, stop putting another empty statement after it.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
This is convenience macro, use it more. This commit was generated
using the following spatch:
@@
symbol node;
identifier old;
identifier ctxt;
type xmlNodePtr;
@@
- xmlNodePtr old;
+ VIR_XPATH_NODE_AUTORESTORE(ctxt);
...
- old = ctxt->node;
... when != old
- ctxt->node = old;
@@
symbol node;
identifier old;
identifier ctxt;
type xmlNodePtr;
@@
- xmlNodePtr old = ctxt->node;
+ VIR_XPATH_NODE_AUTORESTORE(ctxt);
... when != old
- ctxt->node = old;
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The structure is not specific to x86 and thus its cleanup function
should be defined in cpu.h and be available to all users.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
CPU models defined in the cpu_map can use signature/@stepping attribute
to match a limited set of stepping numbers. The value is a bitmap for
bits 0..15 each corresponding to a single stepping value. For example,
stepping='4-6,9' will match 4, 5, 6, and 9. Omitting the attribute is
equivalent to stepping='0-15'.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Thanks to glib allocation functions which abort on OOM the function
cannot ever return NULL.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The CPU models in our cpu_map define their signatures using separate
family and model numbers. Let's store the signatures in the same way in
our runtime representation of the cpu_map.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
It can be used for separating family, model, and stepping numbers from a
single 32b integer as reported by CPUID.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The function will be used for freeing virCPUx86Signatures structure
introduced later in this series.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Later in this series the function will work on a newly introduced
virCPUx86Signatures structure. Let's move it to the place where all
related functions will be added and rename the function as
virCPUx86SignaturesFormat for easier review of the virCPUx86Signatures
patch.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Later in this series the function will work on a newly introduced
virCPUx86Signatures structure. Let's move it to the place were all
related functions will be added and rename the function as
virCPUx86SignaturesMatch for easier review of the virCPUx86Signatures
patch.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Later in this series the function will work on a newly introduced
virCPUx86Signatures structure. Let's move it to the place were all
related functions will be added and rename the function as
virCPUx86SignaturesCopy for easier review of the virCPUx86Signatures
patch.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The hint was introduced a long time ago when broken TSX implementation
was found in Haswell and Broadwell CPUs. Since then many more CPUs with
TSX were introduced and and disabled due to TAA vulnerability.
Thus the hint is not very useful and I think removing it is a better
choice then updating it to cover all current noTSX models.
This partially reverts:
commit 7f127ded657b24e0e55cd5f3539ef5b2dc935908
cpu: Rework cpuCompare* APIs
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The element specifies whether a particular CPU model can be used when
creating a CPU definition from raw CPUID/MSR data. The @host attribute
determines whether the CPU model can be used (host='on') for creating
CPU definition for host capabilities. Usability of the model for domain
capabilities and host-model CPU definitions is controlled by the @guest
attribute.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
