Setting tsc-frequency from x86_def_t is NOP because default tsc_khz
in x86_def_t is 0 and CPUX86State.tsc_khz is also initialized to 0
by default. So there is no need to overwrite tsc_khz with default 0
because field was already initialized to 0.
Custom tsc-frequency setting is not affected due to it being set
without using x86_def_t.
Field tsc_khz in x86_def_t becomes unused with this patch, so drop it
as well.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Move custom features parsing after built-in cpu_model defaults are set
and set custom features directly on CPU instance. That allows to make a
clear distinction between built-in cpu model defaults that eventually
should go into class_init() and extra property setting which is done
after defaults are set on CPU instance.
Impl. details:
* use object_property_parse() property setter so it would be a mechanical
change to switch to global properties later.
* And after all current features/properties are converted into static
properties, it will take a trivial patch to switch to global properties.
Which will allow to:
* get CPU instance initialized with all parameters passed on -cpu ...
cmd. line from object_new() call.
* call cpu_model/featurestr parsing only once before CPUs are created
* open a road for removing CPUxxxState.cpu_model_str field, when other
CPUs are similarly converted to subclasses and static properties.
- re-factor error handling, to use Error instead of fprintf()s, since
it is anyway passed in for property setter.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Commit 8935499831 makes cpuid return to guest host's vendor value
instead of built-in one by default if kvm_enabled() == true and allows
to override this behavior if 'vendor' is specified on -cpu command line.
But every time guest calls cpuid to get 'vendor' value, host's value is
read again and again in default case.
It complicates semantics of vendor property and makes it harder to use.
Instead of reading 'vendor' value from host every time cpuid[vendor] is
called, override 'vendor' value only once in cpu_x86_find_by_name(), when
built-in CPU model is found and if(kvm_enabled() == true).
It provides the same default semantics
if (kvm_enabled() == true) vendor = host's vendor
else vendor = built-in vendor
and then later:
if (custom vendor) vendor = custom vendor
'vendor' value is overridden when user provides it on -cpu command line,
and there is no need for vendor_override field anymore, remove it.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Vendor property setter takes string as vendor value but cpudefs
use uint32_t vendor[123] fields to define vendor value. It makes it
difficult to unify and use property setter for values from cpudefs.
Simplify code by using vendor property setter, vendor[123] fields
are converted into vendor[13] array to keep its value. And vendor
property setter is used to access/set value on CPU.
- Make for() cycle reusable for the next patch by adding
x86_cpu_vendor_words2str()
Intel's CPUID spec[1] says:
"
5.1.1 ...
These registers contain the ASCII string: GenuineIntel
...
"
List[2] of known vendor values shows that they all are 12 ASCII
characters long, padded where necessary with space.
Current supported values are all ASCII characters packed in
ebx, edx, ecx. So lets state that QEMU supports 12 printable ASCII
characters packed in ebx, edx, ecx registers for cpuid(0) instruction.
*1 - http://www.intel.com/Assets/PDF/appnote/241618.pdf
*2 - http://en.wikipedia.org/wiki/CPUID#EAX.3D0:_Get_vendor_ID
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
It is no longer needed since dropping cpudef config file support.
Cleaning this up removes knowledge about other models from x86_def_t,
in preparation for reusing x86_def_t as intermediate step towards pure
QOM X86CPU subclasses.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Catch NULL name argument early to avoid repeated checks.
Similarly, check for -cpu host early and untangle from iterating through
model definitions. This prepares for introducing X86CPU subclasses.
Signed-off-by: Andreas Färber <afaerber@suse.de>
This keeps compatibility on machine-types pc-1.2 and older, and prints a
warning in case the requested configuration won't get the correct
topology.
I couldn't think of a better way to warn about broken topology when in
compat mode other than using error_report(). The warning message will
probably be buried in a log file somewhere, but it's better than
nothing.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This introduces utility functions for the APIC ID calculation, based on:
Intel® 64 Architecture Processor Topology Enumeration
http://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration/
The code should be compatible with AMD's "Extended Method" described at:
AMD CPUID Specification (Publication #25481)
Section 3: Multiple Core Calcuation
as long as:
- nr_threads is set to 1;
- OFFSET_IDX is assumed to be 0;
- CPUID Fn8000_0008_ECX[ApicIdCoreIdSize[3:0]] is set to
apicid_core_width().
Unit tests included.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This function will be used by both the CPU initialization code and the
fw_cfg table initialization code.
Later this function will be updated to generate APIC IDs according to
the CPU topology.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
The CPU ID in KVM is supposed to be the APIC ID, so change the
KVM_CREATE_VCPU call to match it. The current behavior didn't break
anything yet because today the APIC ID is assumed to be equal to the CPU
index, but this won't be true in the future.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This will allow each architecture to define how the VCPU ID is set on
the KVM_CREATE_VCPU ioctl call.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Currently, the pc-1.4 machine init function enables PV EOI and then
calls the pc-1.2 machine init function. The problem with this approach
is that now we can't enable any additional compatibility code inside the
pc-1.2 init function because it would end up enabling the compatibility
behavior on pc-1.3 and pc-1.4 as well.
This reverses the logic so that the pc-1.2 machine init function will
disable PV EOI, and then call the pc-1.4 machine init function.
This way we can change older machine-types to enable compatibility
behavior, and the newer machine-types (pc-1.3, pc-q35-1.4 and
pc-i440fx-1.4) would just use the default behavior.
(This means that one nice side-effect of this change is that pc-q35-1.4
will get PV EOI enabled by default, too)
It would be interesting to eventually change pc_init_pci_no_kvmclock()
and pc_init_isa() to reuse pc_init_pci_1_2() as well (so we don't need
to duplicate compatibility code on those two functions). But this will
be probably much easier to do after we create a PCInitArgs struct for
the PC initialization arguments, and/or after we use global-properties
to implement the compatibility modes present in pc_init_pci_1_2().
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This is a cleanup that tries to solve two small issues:
- We don't need a separate kvm_pv_eoi_features variable just to keep a
constant calculated at compile-time, and this style would require
adding a separate variable (that's declared twice because of the
CONFIG_KVM ifdef) for each feature that's going to be
enabled/disabled by machine-type compat code.
- The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features
even when KVM is disabled at runtime. This small inconsistency in
the cpuid_kvm_features field isn't a problem today because
cpuid_kvm_features is ignored by the TCG code, but it may cause
unexpected problems later when refactoring the CPUID handling code.
This patch eliminates the kvm_pv_eoi_features variable and simply uses
kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it
enables kvm_pv_eoi only if KVM is enabled. I believe this makes the
behavior of enable_kvm_pv_eoi() clearer and easier to understand.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Replace by SYS_BUS_DEVICE() QOM cast macro using a scripted conversion.
Avoids the old macro creeping into new code.
Resolve a Coding Style warning in openpic code.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Replace an if statement using magic numbers for breakpoint type with a
more explicit switch statement. This is to aid readability.
Change the return type and force_dr6_update argument type to bool.
While at it, fix Coding Style issues (missing braces).
Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
"Go To Statement Considered Harmful" -- E. Dijkstra
To avoid an unnecessary goto within the switch statement, move
watchpoint insertion out of the switch statement. Improves readability.
While at it, fix Coding Style issues (missing braces, indentation).
Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
hw_breakpoint_enabled() returned a bit field indicating whether a local
breakpoint and/or global breakpoint was enabled. Avoid this number magic
by using explicit boolean helper functions hw_local_breakpoint_enabled()
and hw_global_breakpoint_enabled(), to aid readability.
Reuse them for the hw_breakpoint_enabled() implementation and change
its return type to bool.
While at it, fix Coding Style issues (missing braces).
Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Implicit use of dr7 bit field is a little hard to understand,
so define constants for them and use them consistently.
Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
kvm_check_features_against_host() should be called when features can't
be changed, and when features are converted to properties it would be
possible to change them until realize time, so correct way is to call
kvm_check_features_against_host() in x86_cpu_realize().
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Freeing resources in one place would require setting 'error'
to not NULL, so add some more error reporting before jumping to
exit branch.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
No functional change, needed for simplifying conversion to properties.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This adds the following feature words to the list of flags to be checked
by kvm_check_features_against_host():
- cpuid_7_0_ebx_features
- ext4_features
- kvm_features
- svm_features
This will ensure the "enforce" flag works as it should: it won't allow
QEMU to be started unless every flag that was requested by the user or
defined in the CPU model is supported by the host.
This patch may cause existing configurations where "enforce" wasn't
preventing QEMU from being started to abort QEMU. But that's exactly the
point of this patch: if a flag was not supported by the host and QEMU
wasn't aborting, it was a bug in the "enforce" code.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Feature names were taken from the X86_FEATURE_* constants in the Linux
kernel code.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Instead of carrying the CPUID leaf/register and feature name array on
the model_features_t struct, move that information into
feature_word_info so it can be reused by other functions.
The goal is to eventually kill model_features_t entirely, but to do that
we have to either convert x86_def_t.features to an array or use
offsetof() inside FeatureWordInfo (to replace the pointers inside
model_features_t). So by now just move most of the model_features_t
fields to FeatureWordInfo except for the two pointers to local
arguments.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This introduces a FeatureWord enum, FeatureWordInfo struct (with
generation information about a feature word), and a FeatureWordArray
typedef, and changes add_flagname_to_bitmaps() code and
cpu_x86_parse_featurestr() to use the new typedefs instead of separate
variables for each feature word.
This will help us keep the code at kvm_check_features_against_host(),
cpu_x86_parse_featurestr() and add_flagname_to_bitmaps() sane while
adding new feature name arrays.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
KVM_CAP_PV_MMU capability reporting was removed from the kernel since
v2.6.33 (see commit a68a6a7282373), and was completely removed from the
kernel since v3.3 (see commit fb92045843). It doesn't make sense to keep
it enabled by default, as it would cause unnecessary hassle when using
the "enforce" flag.
This disables kvm_mmu on all machine-types. With this fix, the possible
scenarios when migrating from QEMU <= 1.3 to QEMU 1.4 are:
------------+----------+----------------------------------------------------
src kernel | dst kern.| Result
------------+----------+----------------------------------------------------
>= 2.6.33 | any | kvm_mmu was already disabled and will stay disabled
<= 2.6.32 | >= 3.3 | correct live migration is impossible
<= 2.6.32 | <= 3.2 | kvm_mmu will be disabled on next guest reboot *
------------+----------+----------------------------------------------------
* If they are running kernel <= 2.6.32 and want kvm_mmu to be kept
enabled on guest reboot, they can explicitly add +kvm_mmu to the QEMU
command-line. Using 2.6.33 and higher, it is not possible to enable
kvm_mmu explicitly anymore.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Note that target-alpha accesses this field from TCG, now using a
negative offset. Therefore the field is placed last in CPUState.
Pass PowerPCCPU to [kvm]ppc_fixup_cpu() to facilitate this change.
Move common parts of mips cpu_state_reset() to mips_cpu_reset().
Acked-by: Richard Henderson <rth@twiddle.net> (for alpha)
[AF: Rebased onto ppc CPU subclasses and openpic changes]
Signed-off-by: Andreas Färber <afaerber@suse.de>
To facilitate the field movements, pass MIPSCPU to malta_mips_config();
avoid that for mips_cpu_map_tc() since callers only access MIPS Thread
Contexts, inside TCG helpers.
Signed-off-by: Andreas Färber <afaerber@suse.de>
((pde & 0x1fe000) << 19) is the bits 39:32 of the final physical address, and
we shouldn't use unit32_t to calculate it. Convert the type to hwaddr to fix
this problem.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Since cpudef config is not supported anymore and all remaining sources
now always set x86_def_t.vendor[123] fields, remove setting default
vendor to simplify future re-factoring.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
When CPU properties are implemented, ext2_features may change
between object_new(CPU) and cpu_realize_fn(). Sanitizing
ext2_features for AMD based CPU at realize() time will keep
current behavior after CPU features are converted to properties.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Now that all entries have check_feat=~0 in
kvm_check_features_against_host(), we can eliminate check_feat entirely
and make the code check all bits.
This patch shouldn't introduce any behavior change, as check_feat is set
to ~0 on all entries.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
When nested SVM is supported, the kernel returns the SVM flag on
GET_SUPPORTED_CPUID[1], so we can check the SVM flag safely in
kvm_check_features_against_host().
I don't know why the original code ignored the SVM flag. Maybe it was
because kvm_cpu_fill_host() used the CPUID instruction directly instead
of GET_SUPPORTED_CPUID
[1] Older kernels (before v2.6.37) returned the SVM flag even if nested
SVM was _not_ supported. So the only cases where this patch should
change behavior is when SVM is being requested by the user or the
CPU model, but not supported by the host. And on these cases we
really want QEMU to abort if the "enforce" option is set.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
I have no idea why PPRO_FEATURES was being ignored on the check of the
CPUID.80000001H.EDX bits. I believe it was a mistake, and it was
supposed to be ~(PPRO_FEATURES & CPUID_EXT2_AMD_ALIASES) or just
~CPUID_EXT2_AMD_ALIASES, because some time ago kvm_cpu_fill_host() used
the CPUID instruction directly (instead of
kvm_arch_get_supported_cpuid()).
But now kvm_cpu_fill_host() uses kvm_arch_get_supported_cpuid(), and
kvm_arch_get_supported_cpuid() returns all supported bits for
CPUID.80000001H.EDX, even the AMD aliases (that are explicitly copied
from CPUID.01H.EDX), so we can make the code check/enforce all the
CPUID.80000001H.EDX bits.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
We don't need any hack to ignore CPUID_EXT_HYPERVISOR anymore, because
kvm_arch_get_supported_cpuid() now sets CPUID_EXT_HYPERVISOR properly.
So, this shouldn't introduce any behavior change, but it makes the code
simpler.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
The -cpu check/enforce warnings are printing incorrect information about the
missing flags. There are no feature flags on CPUID leaves 0 and 0x80000000, but
there were references to 0 and 0x80000000 in the table at
kvm_check_features_against_host().
This changes the model_features_t struct to contain the register number as
well, so the error messages print the correct CPUID leaf+register information,
instead of wrong CPUID leaf numbers.
This also changes the format of the error messages, so they follow the
"CPUID.<leaf>.<register>.<name> [bit <offset>]" convention used in Intel
documentation. Example output:
$ qemu-system-x86_64 -machine pc-1.0,accel=kvm -cpu Opteron_G4,+ia64,enforce
warning: host doesn't support requested feature: CPUID.01H:EDX.ia64 [bit 30]
warning: host doesn't support requested feature: CPUID.01H:ECX.xsave [bit 26]
warning: host doesn't support requested feature: CPUID.01H:ECX.avx [bit 28]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.abm [bit 5]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.sse4a [bit 6]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.misalignsse [bit 7]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.3dnowprefetch [bit 8]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.xop [bit 11]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.fma4 [bit 16]
Unable to find x86 CPU definition
$
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
When using -cpu host, we don't need to use the kvm_default_features
variable, as the user is explicitly asking QEMU to enable all feature
supported by the host.
This changes the kvm_cpu_fill_host() code to use GET_SUPPORTED_CPUID to
initialize the kvm_features field, so we get all host KVM features
enabled.
This will also allow us to properly check/enforce KVM features inside
kvm_check_features_against_host() later. For example, we will be able to
make this:
$ qemu-system-x86_64 -cpu ...,+kvm_pv_eoi,enforce
refuse to start if kvm_pv_eoi is not supported by the host (after we fix
kvm_check_features_against_host() to check KVM flags as well).
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
The existing -cpu host code simply sets every bit inside svm_features
(initializing it to -1), and that makes it impossible to make the
enforce/check options work properly when the user asks for SVM features
explicitly in the command-line.
So, instead of initializing svm_features to -1, use GET_SUPPORTED_CPUID
to fill only the bits that are supported by the host (just like we do
for all other CPUID feature words inside kvm_cpu_fill_host()).
This will keep the existing behavior (as filter_features_for_kvm()
already uses GET_SUPPORTED_CPUID to filter svm_features), but will allow
us to properly check for KVM features inside
kvm_check_features_against_host() later.
For example, we will be able to make this:
$ qemu-system-x86_64 -cpu ...,+pfthreshold,enforce
refuse to start if the SVM "pfthreshold" feature is not supported by the
host (after we fix kvm_check_features_against_host() to check SVM flags
as well).
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
* 'qom-cpu' of git://repo.or.cz/qemu/afaerber:
MAINTAINERS: Include X86CPU in CPU maintenance area
cpu: Move kvm_run into CPUState
cpu: Move kvm_state field into CPUState
ppc_booke: Pass PowerPCCPU to ppc_booke_timers_init()
ppc4xx_devs: Return PowerPCCPU from ppc4xx_init()
ppc_booke: Pass PowerPCCPU to {decr,fit,wdt} timer callbacks
ppc: Pass PowerPCCPU to [h]decr timer callbacks
ppc: Pass PowerPCCPU to [h]decr callbacks
ppc: Pass PowerPCCPU to ppc_set_irq()
kvm: Pass CPUState to kvm_vcpu_ioctl()
kvm: Pass CPUState to kvm_arch_*
cpu: Move kvm_fd into CPUState
qdev-properties.c: Separate core from the code used only by qemu-system-*
qdev: Coding style fixes
cpu: Introduce CPUListState struct
target-alpha: Add support for -cpu ?
target-alpha: Turn CPU definitions into subclasses
target-alpha: Avoid leaking the alarm timer over reset
alpha: Pass AlphaCPU array to Typhoon
target-alpha: Let cpu_alpha_init() return AlphaCPU
This fixes a subtle bug. A bug that probably won't cause trouble for any
existing OS, but a bug anyway:
Intel SDM Volume 2, CPUID Instruction states:
> Two types of information are returned: basic and extended function
> information. If a value entered for CPUID.EAX is higher than the maximum
> input value for basic or extended function for that processor then the
> data for the highest basic information leaf is returned. For example,
> using the Intel Core i7 processor, the following is true:
>
> CPUID.EAX = 05H (* Returns MONITOR/MWAIT leaf. *)
> CPUID.EAX = 0AH (* Returns Architectural Performance Monitoring leaf. *)
> CPUID.EAX = 0BH (* Returns Extended Topology Enumeration leaf. *)
> CPUID.EAX = 0CH (* INVALID: Returns the same information as CPUID.EAX = 0BH. *)
> CPUID.EAX = 80000008H (* Returns linear/physical address size data. *)
> CPUID.EAX = 8000000AH (* INVALID: Returns same information as CPUID.EAX = 0BH. *)
AMD's CPUID Specification, on the other hand, is less specific:
> The CPUID instruction supports two sets or ranges of functions,
> standard and extended.
>
> • The smallest function number of the standard function range is
> Fn0000_0000. The largest function num- ber of the standard function
> range, for a particular implementation, is returned in CPUID
> Fn0000_0000_EAX.
>
> • The smallest function number of the extended function range is
> Fn8000_0000. The largest function num- ber of the extended function
> range, for a particular implementation, is returned in CPUID
> Fn8000_0000_EAX.
>
> Functions that are neither standard nor extended are undefined and
> should not be relied upon.
QEMU's behavior matched Intel's specification before, but this was
changed by commit b3baa152aa. This patch
restores the behavior documented by Intel when cpuid_xlevel2 is 0.
The existing behavior when cpuid_xlevel2 is set (falling back to
level=cpuid_xlevel) is being kept, as I couldn't find any public
documentation on the CPUID 0xC0000000 function range on Centaur CPUs.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
