target-i386: Simplify cpu_x86_find_by_name()

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>
target-i386: Drop redundant list of CPU definitions

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>
target-i386: Print deprecation warning if xlevel < 0x80000000

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
target-i386: Replace uint32_t vendor fields by vendor string in x86_def_t

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>
target-i386: Remove vendor_override field from CPUX86State

Commit 8935499831312 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>