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57f26ae729
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
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|---|---|---|
| .. | ||
| arch_dump.c | ||
| arch_memory_mapping.c | ||
| cc_helper_template.h | ||
| cc_helper.c | ||
| cpu-qom.h | ||
| cpu.c | ||
| cpu.h | ||
| excp_helper.c | ||
| fpu_helper.c | ||
| helper.c | ||
| helper.h | ||
| hyperv.c | ||
| hyperv.h | ||
| int_helper.c | ||
| ioport-user.c | ||
| kvm_i386.h | ||
| kvm-stub.c | ||
| kvm.c | ||
| machine.c | ||
| Makefile.objs | ||
| mem_helper.c | ||
| misc_helper.c | ||
| ops_sse_header.h | ||
| ops_sse.h | ||
| seg_helper.c | ||
| shift_helper_template.h | ||
| smm_helper.c | ||
| svm_helper.c | ||
| svm.h | ||
| TODO | ||
| translate.c | ||