Commit graph

100 commits

Author SHA1 Message Date
Xiaoyao Li 576be63f06
target/i386: define a new MSR based feature word - FEAT_CORE_CAPABILITY
MSR IA32_CORE_CAPABILITY is a feature-enumerating MSR, which only
enumerates the feature split lock detection (via bit 5) by now.

The existence of MSR IA32_CORE_CAPABILITY is enumerated by CPUID.7_0:EDX[30].

The latest kernel patches about them can be found here:
https://lkml.org/lkml/2019/4/24/1909

Backports commit 597360c0d8ebda9ca6f239db724a25bddec62b2f from qemu
2019-06-25 18:59:52 -05:00
Richard Henderson a672b89e3b
cpu: Introduce cpu_set_cpustate_pointers
Consolidate some boilerplate from foo_cpu_initfn.

Backports commit 7506ed902eb97fe4e2a1dd16766c621d32ecc40d from qemu
2019-06-12 12:27:16 -04:00
Richard Henderson 187778c781
target/i386: Use env_cpu, env_archcpu
Cleanup in the boilerplate that each target must define.
Replace x86_env_get_cpu with env_archcpu. The combination
CPU(x86_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.

Backports commit 6aa9e42f27331be34e06d4d66f92f2272868f96a from qemu
2019-06-12 11:46:35 -04:00
Wanpeng Li b41364fdc5
i386: Enable IA32_MISC_ENABLE MWAIT bit when exposing mwait/monitor
The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR
IA32_MISC_ENABLE MWAIT bit and as userspace has control of them
both, it is userspace's job to configure both bits to match on
the initial setup.

Backports commit 4cfd7bab3f5564f6c1a23b06f73d5aa2f957cd16 from qemu
2019-06-04 13:17:43 -04:00
Richard Henderson 0412b3be8a
target/i386: Implement CPUID_EXT_RDRAND
We now have an interface for guest visible random numbers.

Backports commit 369fd5ca66810b2ddb16e23a497eabe59385eceb from qemu with
the actual RNG portion disabled for the time being.
2019-05-23 15:12:50 -04:00
Paolo Bonzini 1341e371a8
target/i386: add MDS-NO feature
Microarchitectural Data Sampling is a hardware vulnerability which allows
unprivileged speculative access to data which is available in various CPU
internal buffers.

Some Intel processors use the ARCH_CAP_MDS_NO bit in the
IA32_ARCH_CAPABILITIES
MSR to report that they are not vulnerable, make it available to
guests.

Backports commit 20140a82c67467f53814ca197403d5e1b561a5e5 from qemu
2019-05-23 14:49:20 -04:00
Paolo Bonzini a4f2517f46
target/i386: define md-clear bit
md-clear is a new CPUID bit which is set when microcode provides the
mechanism to invoke a flush of various exploitable CPU buffers by invoking
the VERW instruction.

Backports commit b2ae52101fca7f9547ac2f388085dbc58f8fe1c0 from qemu
2019-05-23 14:48:18 -04:00
Richard Henderson fe9ac6e1c4
target/i386: Convert to CPUClass::tlb_fill
We do not support probing, but we do not need it yet either.

Backports commit 5d0044212c375c0696baef7bba13699277dac5b5 from qemu
2019-05-16 17:08:14 -04:00
Stanislav Lanci 64f51949a7
Pass through cache information for TOPOEXT CPUs
Backports commit a4e0b436f44a4bb47ed4a75b0c05d2547cf12b1c from qemu
2019-04-30 09:15:25 -04:00
Pu Wen 4bbf02a5f6
i386: Add new Hygon 'Dhyana' CPU model
Add a new base CPU model called 'Dhyana' to model processors from Hygon
Dhyana(family 18h), which derived from AMD EPYC(family 17h).

The following features bits have been removed compare to AMD EPYC:
aes, pclmulqdq, sha_ni

The Hygon Dhyana support to KVM in Linux is already accepted upstream[1].
So add Hygon Dhyana support to Qemu is necessary to create Hygon's own
CPU model.

Reference:
[1] https://git.kernel.org/tip/fec98069fb72fb656304a3e52265e0c2fc9adf87

Backports commit 8d031cec366f26669807eb43f61eb335973b7053 from qemu
2019-04-30 09:13:55 -04:00
Eduardo Habkost df51e8bbb3
i386: Disable OSPKE on CPU model definitions
Currently, the Cascadelake-Server, Icelake-Client, and
Icelake-Server are always generating the following warning:

qemu-system-x86_64: warning: \
host doesn't support requested feature: CPUID.07H:ECX [bit 4]

This happens because OSPKE was never returned by
GET_SUPPORTED_CPUID or x86_cpu_get_supported_feature_word().
OSPKE is a runtime flag automatically set by the KVM module or by
TCG code, was always cleared by x86_cpu_filter_features(), and
was not supposed to appear on the CPU model table.

Remove the OSPKE flag from the CPU model table entries, to avoid
the bogus warning and avoid returning invalid feature data on
query-cpu-* QMP commands. As OSPKE was always cleared by
x86_cpu_filter_features(), this won't have any guest-visible
impact.

Include a test case that should detect the problem if we introduce
a similar bug again.

Fixes: c7a88b52f62b ("i386: Add new model of Cascadelake-Server")
Fixes: 8a11c62da914 ("i386: Add new CPU model Icelake-{Server,Client}")

Backports commit bb4928c7cafe50ab2137a0034e350ef1bfa044d9 from qemu
2019-03-22 09:46:44 -04:00
Eduardo Habkost a71df717c9
i386: Make arch_capabilities migratable
Now that kvm_arch_get_supported_cpuid() will only return
arch_capabilities if QEMU is able to initialize the MSR properly,
we know that the feature is safely migratable.

Backports commit 014018e19b3c54dd1bf5072bc912ceffea40abe8 from qemu
2019-03-22 09:45:43 -04:00
Lioncash 8f688748c4
translate/i386: Restore Qemu's ordering of CPU and cache definitions
Like the previous two changes, this restores the layout of Qemu's
designated initializers.
2019-03-08 01:51:27 -05:00
Robert Hoo c8a49d8593
Revert "i386: Add CPUID bit for PCONFIG"
This reverts commit 5131dc433df54b37e8e918d8fba7fe10344e7a7b.
For new instruction 'PCONFIG' will not be exposed to guest.

Backports commit 712f807e1965c8f1f1da5bbec2b92a8c540e6631 from qemu
2019-02-07 08:56:40 -05:00
Paolo Bonzini 4234209a64
i386: remove the 'INTEL_PT' CPUID bit from named CPU models
Processor tracing is not yet implemented for KVM and it will be an
opt in feature requiring a special module parameter.
Disable it, because it is wrong to enable it by default and
it is impossible that no one has ever used it.

Backports commit 4c257911dcc7c4189768e9651755c849ce9db4e8 from qemu
2019-02-07 08:55:32 -05:00
Robert Hoo 2c61060ecb
i386: remove the new CPUID 'PCONFIG' from Icelake-Server CPU model
PCONFIG is not available to guests; it must be specifically enabled
using the PCONFIG_ENABLE execution control. Disable it, because
no one can ever use it.

Backports commit 76e5a4d58357b9d077afccf7f7c82e17f733b722 from qemu
2019-02-07 08:54:13 -05:00
Vitaly Kuznetsov d13b35769d
i386: Enable NPT and NRIPSAVE for AMD CPUs
Modern AMD CPUs support NPT and NRIPSAVE features and KVM exposes these
when present. NRIPSAVE apeared somewhere in Opteron_G3 lifetime (e.g.
QuadCore AMD Opteron 2378 has is but QuadCore AMD Opteron HE 2344 doesn't),
NPT was introduced a bit earlier.

Add the FEAT_SVM leaf to Opteron_G4/G5 and EPYC/EPYC-IBPB cpu models.

Backports commit 9fe8b7be17eaac4cfde4083000cc96747d7cf4f8 from qemu
2019-02-03 17:55:28 -05:00
Tao Xu 72afbf6d48
i386: Update stepping of Cascadelake-Server
Update the stepping from 5 to 6, in order that
the Cascadelake-Server CPU model can support AVX512VNNI
and MSR based features exposed by ARCH_CAPABILITIES.

Backports commit b0a1980384fc265d91de7e09aa5fe531a69e6288 from qemu
2019-02-03 17:55:28 -05:00
Vitaly Kuznetsov b6cc2c4e06
i386/kvm: add a comment explaining why .feat_names are commented out for Hyper-V feature bits
Hyper-V .feat_names are, unlike hardware features, commented out and it is
not obvious why we do that. Document the current status quo.

Backports commit abd5fc4c862d033a989552914149f01c9476bb16 from qemu
2019-01-14 15:02:35 -05:00
Vitaly Kuznetsov 2873612479
i386/kvm: expose HV_CPUID_ENLIGHTMENT_INFO.EAX and HV_CPUID_NESTED_FEATURES.EAX as feature words
It was found that QMP users of QEMU (e.g. libvirt) may need
HV_CPUID_ENLIGHTMENT_INFO.EAX/HV_CPUID_NESTED_FEATURES.EAX information. In
particular, 'hv_tlbflush' and 'hv_evmcs' enlightenments are only exposed in
HV_CPUID_ENLIGHTMENT_INFO.EAX.

HV_CPUID_NESTED_FEATURES.EAX is exposed for two reasons: convenience
(we don't need to export it from hyperv_handle_properties() and as
future-proof for Enlightened MSR-Bitmap, PV EPT invalidation and
direct virtual flush features.

Backports commit a2b107dbbd342ff2077aa5af705efaf68c375459 from qemu
2019-01-14 15:01:13 -05:00
Paolo Bonzini bf6192276b
target/i386: Disable MPX support on named CPU models
MPX support is being phased out by Intel; GCC has dropped it, Linux
is also going to do that. Even though KVM will have special code
to support MPX after the kernel proper stops enabling it in XCR0,
we probably also want to deprecate that in a few years. As a start,
do not enable it by default for any named CPU model starting with
the 4.0 machine types; this include Skylake, Icelake and Cascadelake.

Backports commit ecb85fe48cacb2f8740186e81f2f38a2e02bd963 from qemu
2019-01-14 14:54:40 -05:00
Borislav Petkov 152fdb49de
target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models CPU models
The missing functionality was added ~3 years ago with the Linux commit

46896c73c1a4 ("KVM: svm: add support for RDTSCP")

so reenable RDTSCP support on those CPU models.

Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support
(the real hardware doesn't have it. K8 got RDTSCP support with the NPT
models, i.e., models >= 0x40).

Document the host's minimum required kernel version, while at it.

Backports commit 483c6ad426dbab72d912fe4793d7d558671aa727 from qemu
2019-01-14 14:50:22 -05:00
Eduardo Habkost 030aa55c08
i386: Add stibp flag name
The STIBP flag may be supported by the host KVM module, so QEMU
can allow it to be configured manually, and it can be exposed to
guests when using "-cpu host".

No additional migration code is required because the whole
contents of spec_ctrl is already migrated in the "cpu/spec_ctrl"
section.

Backports commit 0e8916582991b9fd0b94850a8444b8b80d0a0955 from qemu
2018-12-18 03:48:53 -05:00
Liu Jingqi 10d7f18674
x86/cpu: Enable MOVDIR64B cpu feature
MOVDIR64B moves 64-bytes as direct-store with 64-bytes write atomicity.
Direct store is implemented by using write combining (WC) for writing
data directly into memory without caching the data.

The bit definition:
CPUID.(EAX=7,ECX=0):ECX[bit 28] MOVDIR64B

The release document ref below link:
https://software.intel.com/sites/default/files/managed/c5/15/\
architecture-instruction-set-extensions-programming-reference.pdf

Backports commit 1c65775ffc2dbd276a8bffe592feba0e186a151c from qemu
2018-12-18 03:48:19 -05:00
Liu Jingqi 6aa3cd24fd
x86/cpu: Enable MOVDIRI cpu feature
MOVDIRI moves doubleword or quadword from register to memory through
direct store which is implemented by using write combining (WC) for
writing data directly into memory without caching the data.

The bit definition:
CPUID.(EAX=7,ECX=0):ECX[bit 27] MOVDIRI

The release document ref below link:
https://software.intel.com/sites/default/files/managed/c5/15/\
architecture-instruction-set-extensions-programming-reference.pdf

Backports commit 24261de4916596d8ab5f5fee67e9e7a19e8325a5 from qemu
2018-12-18 03:46:49 -05:00
Tao Xu 0aaa7f7ce9
i386: Add PKU on Skylake-Server CPU model
As the release document ref below link (page 13):
https://software.intel.com/sites/default/files/managed/c5/15/\
architecture-instruction-set-extensions-programming-reference.pdf

PKU is supported in Skylake Server (Only Server) and later, and
on Intel(R) Xeon(R) Processor Scalable Family. So PKU is supposed
to be in Skylake-Server CPU model. And PKU's CPUID has been
exposed to QEMU. But PKU can't be find in Skylake-Server CPU
model in the code. So this patch will fix this issue in
Skylake-Server CPU model.

Backports commit 09b9ee643f90ef95e30e594df2a3c83ccaf75b1f from qemu
2018-11-11 08:09:47 -05:00
Tao Xu b004139ea1
i386: Add new model of Cascadelake-Server
New CPU models mostly inherit features from ancestor Skylake-Server,
while addin new features: AVX512_VNNI, Intel PT.
SSBD support for speculative execution
side channel mitigations.

Note:

On Cascadelake, some capabilities (RDCL_NO, IBRS_ALL, RSBA,
SKIP_L1DFL_VMENTRY and SSB_NO) are enumerated by MSR.
These features rely on MSR based feature support patch.
Will be added later after that patch's in.
http://lists.nongnu.org/archive/html/qemu-devel/2018-09/msg00074.html

Backports commit c7a88b52f62b30c04158eeb07f73e3f72221b6a8 from qemu
2018-11-11 08:08:39 -05:00
Robert Hoo 24733280b2
x86: define a new MSR based feature word -- FEATURE_WORDS_ARCH_CAPABILITIES
Note RSBA is specially treated -- no matter host support it or not, qemu
pretends it is supported.

Backports commit d86f963694df27f11b3681ffd225c9362de1b634 from qemu
2018-11-11 08:07:33 -05:00
Robert Hoo 947b021266
x86: Data structure changes to support MSR based features
Add FeatureWordType indicator in struct FeatureWordInfo.
Change feature_word_info[] accordingly.
Change existing functions that refer to feature_word_info[] accordingly.

Backports commit 07585923485952bf4cb7da563c9f91fecc85d09c from qemu
2018-11-11 08:06:18 -05:00
Sebastian Andrzej Siewior a09a074255
i386: correct cpu_x86_cpuid(0xd)
Intel SDM says for CPUID function 0DH, sub-function 0:

| • ECX enumerates the size (in bytes) required by the XSAVE instruction for an
| XSAVE area containing all the user state components supported by this
| processor.
| • EBX enumerates the size (in bytes) required by the XSAVE instruction for an
| XSAVE area containing all the user state components corresponding to bits
| currently set in XCR0.

Backports commit de2e68c902f7b6e438b0fa3cfedd74a06a20704f from qemu
2018-11-11 07:52:43 -05:00
Paolo Bonzini 0bc0ff320c
target/i386: unify masking of interrupts
Interrupt handling depends on various flags in env->hflags or env->hflags2,
and the exact detail were not exactly replicated between x86_cpu_has_work
and x86_cpu_exec_interrupt. Create a new function that extracts the
highest-priority non-masked interrupt, and use it in both functions.

Backports commit 92d5f1a4147c3722b5e9a8bcfb7dc261b7a8b855 from qemu
2018-10-04 04:19:57 -04:00
Lioncash 34b22968a4
target/i386/cpu: Use type_register instead of type_register_static in x86_cpu_register_types()
The lifetime of the TypeInfo instance doesn't live indefinitely, so we
should be using the regular type_register().
2018-09-03 17:28:54 -04:00
Lioncash 2beb139304
i386: Fix initialization of x86 targets 2018-09-03 09:14:35 -04:00
Eduardo Habkost f4879ae89f
i386: Disable TOPOEXT by default on "-cpu host"
Enabling TOPOEXT is always allowed, but it can't be enabled
blindly by "-cpu host" because it may make guests crash if the
rest of the cache topology information isn't provided or isn't
consistent.

This addresses the bug reported at:
https://bugzilla.redhat.com/show_bug.cgi?id=1613277

Backports commit 7210a02c58572b2686a3a8d610c6628f87864aed from qemu
2018-08-17 14:34:02 -04:00
Wanpeng Li 1f85fbc4d6
target-i386: adds PV_SEND_IPI CPUID feature bit
Adds PV_SEND_IPI CPUID feature bit.

Backports commit 7f710c32bb893c68b931c68265f0427c032eb7f4 from qemu
2018-08-17 14:30:57 -04:00
Robert Hoo 5e97271942
i386: Add new CPU model Icelake-{Server,Client}
New CPU models mostly inherit features from ancestor Skylake, while addin new
features: UMIP, New Instructions ( PCONIFIG (server only), WBNOINVD,
AVX512_VBMI2, GFNI, AVX512_VNNI, VPCLMULQDQ, VAES, AVX512_BITALG),
Intel PT and 5-level paging (Server only). As well as
IA32_PRED_CMD, SSBD support for speculative execution
side channel mitigations.

Note:
For 5-level paging, Guest physical address width can be configured, with
parameter "phys-bits". Unless explicitly specified, we still use its default
value, even for Icelake-Server cpu model.
At present, hold on expose IA32_ARCH_CAPABILITIES to guest, as 1) This MSR
actually presents more than 1 'feature', maintainers are considering expanding current
features presentation of only CPUIDs to MSR bits; 2) a reasonable default value
for MSR_IA32_ARCH_CAPABILITIES needs to settled first. These 2 are actully
beyond Icelake CPU model itself but fundamental. So split these work apart
and do it later.
https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg00774.html
https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg00796.html

Backports commit 8a11c62da9146dd89aee98947e6bd831e65a970d from qemu
2018-08-17 14:30:13 -04:00
Robert Hoo 0e16ff259b
i386: Add CPUID bit for WBNOINVD
WBNOINVD: Write back and do not invalidate cache, enumerated by
CPUID.(EAX=80000008H, ECX=0):EBX[bit 9].

Backports commit 59a80a19ca31a6fff9fdbb6b4cf55a5a0767c3bc from qemu
2018-08-17 14:29:10 -04:00
Robert Hoo 8b59666ae6
i386: Add CPUID bit for PCONFIG
PCONFIG: Platform configuration, enumerated by CPUID.(EAX=07H, ECX=0):
EDX[bit18].

Backports commit 5131dc433df54b37e8e918d8fba7fe10344e7a7b from qemu
2018-08-17 14:28:11 -04:00
Robert Hoo 44e0a97e0b
i386: Add CPUID bit and feature words for IA32_ARCH_CAPABILITIES MSR
Support of IA32_PRED_CMD MSR already be enumerated by same CPUID bit as
SPEC_CTRL.

At present, mark CPUID_7_0_EDX_ARCH_CAPABILITIES unmigratable, per Paolo's
comment.

Backports commit 3fc7c73139d2d38ae80c3b0bc963b1ac1555924c from qemu
2018-08-17 14:27:28 -04:00
Eduardo Habkost dcb82d69e1
i386: Rename enum CacheType members
Rename DCACHE to DATA_CACHE and ICACHE to INSTRUCTION_CACHE.
This avoids conflict with Linux asm/cachectl.h macros and fixes
build failure on mips hosts.

Backports commit 5f00335aecafc9ad56592d943619d3252f8941f1 from qemu
2018-07-24 21:34:10 -04:00
Philippe Mathieu-Daudé f5698ff9a5
x86/cpu: Use definitions from qemu/units.h
Backports commit 6a4e0614c3e2ca01ac030e9c486c77d4d7225021 from qemu
2018-07-03 19:48:38 -04:00
Babu Moger ec6b1f1554
i386: Enable TOPOEXT feature on AMD EPYC CPU
Enable TOPOEXT feature on EPYC CPU. This is required to support
hyperthreading on VM guests. Also extend xlevel to 0x8000001E.

Disable topoext on PC_COMPAT_2_12 and keep xlevel 0x8000000a.

Backports commit e00516475c270dcb6705753da96063f95699abf2 from qemu
2018-07-03 00:32:50 -04:00
Babu Moger b5f47a4884
i386: Fix up the Node id for CPUID_8000_001E
This is part of topoext support. To keep the compatibility, it is better
we support all the combination of nr_cores and nr_threads currently
supported. By allowing more nr_cores and nr_threads, we might end up with
more nodes than we can actually support with the real hardware. We need to
fix up the node id to make this work. We can achieve this by shifting the
socket_id bits left to address more nodes.

Backports commit 631be32155dbafa1fe886f2488127956c9120ba6 from qemu
2018-07-03 00:31:38 -04:00
Konrad Rzeszutek Wilk 475062aca9
i386: Define AMD's no SSB mitigation needed.
AMD future CPUs expose a mechanism to tell the guest that the
Speculative Store Bypass Disable is not needed and that the
CPU is all good.

This is exposed via the CPUID 8000_0008.EBX[26] bit.

See 124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf

A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889

Backports commit 254790a909a2f153d689bfa7d8e8f0386cda870d from qemu
2018-07-03 00:24:58 -04:00
Konrad Rzeszutek Wilk 0023d048aa
i386: define the AMD 'amd-ssbd' CPUID feature bit
AMD future CPUs expose _two_ ways to utilize the Intel equivalant
of the Speculative Store Bypass Disable. The first is via
the virtualized VIRT_SPEC CTRL MSR (0xC001_011f) and the second
is via the SPEC_CTRL MSR (0x48). The document titled:
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf

gives priority of SPEC CTRL MSR over the VIRT SPEC CTRL MSR.

A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889

Anyhow, this means that on future AMD CPUs there will be _two_ ways to
deal with SSBD.

Backports commit a764f3f7197f4d7ad8fe8424269933de912224cb from qemu
2018-07-03 00:24:24 -04:00
Eduardo Habkost bffd8c6244
i386: Remove ospke CPUID flag name
OSPKE is not a static feature flag: it changes dynamically at
runtime depending on CR4, and it was never configurable: KVM
never returned OSPKE on GET_SUPPORTED_CPUID, and on TCG enables
it automatically if CR4_PKE_MASK is set.

Remove OSPKE from the feature name array so users don't try to
configure it manually.

Backports commit 9ccb9784b57804f5c74434ad6ccb66650a015ffc from qemu
2018-07-03 00:23:33 -04:00
Eduardo Habkost f294aa7cb5
i386: Remove osxsave CPUID flag name
OSXAVE is not a static feature flag: it changes dynamically at
runtime depending on CR4, and it was never configurable: KVM
never returned OSXSAVE on GET_SUPPORTED_CPUID, and it is not
included in TCG_EXT_FEATURES.

Remove OSXSAVE from the feature name array so users don't try to
configure it manually.

Backports commit f1a23522b03a569f13aad49294bb4c4b1a9500c7 from qemu
2018-07-03 00:22:32 -04:00
Babu Moger c07a5c06e7
i386: Add support for CPUID_8000_001E for AMD
Add support for cpuid leaf CPUID_8000_001E. Build the config that closely
match the underlying hardware. Please refer to the Processor Programming
Reference (PPR) for AMD Family 17h Model for more details.

Backports commit ed78467a214595a63af7800a073a03ffe37cd7db from qemu
2018-07-03 00:21:23 -04:00
Babu Moger d4ad9e37a2
i386: Populate AMD Processor Cache Information for cpuid 0x8000001D
Add information for cpuid 0x8000001D leaf. Populate cache topology information
for different cache types (Data Cache, Instruction Cache, L2 and L3) supported
by 0x8000001D leaf. Please refer to the Processor Programming Reference (PPR)
for AMD Family 17h Model for more details.

Backports commit 8f4202fb1080f86958782b1fca0bf0279f67d136 from qemu
2018-06-15 11:52:28 -04:00
Eduardo Habkost 7837f23cd9
i386: Clean up cache CPUID code
Always initialize CPUCaches structs with cache information, even
if legacy_cache=true. Use different CPUCaches struct for
CPUID[2], CPUID[4], and the AMD CPUID leaves.

This will simplify a lot the logic inside cpu_x86_cpuid()

Backports commit a9f27ea9adc8c695197bd08f2e938ef7b4183f07 from qemu
2018-06-15 11:51:09 -04:00