KVM: x86: Update KVM-only leaf handling to allow for 100% KVM-only leafs

mainline inclusion
from mainline-v6.2-rc1
commit 047c7229
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I8GYV5
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=047c7229906152fb85c23dc18fd25a00cd7cb4de



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Intel-SIG: commit 047c7229 ("KVM: x86: Update KVM-only leaf handling to allow for 100% KVM-only leafs")

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KVM: x86: Update KVM-only leaf handling to allow for 100% KVM-only leafs

Rename kvm_cpu_cap_init_scattered() to kvm_cpu_cap_init_kvm_defined() in
anticipation of adding KVM-only CPUID leafs that aren't recognized by the
kernel and thus not scattered, i.e. for leafs that are 100% KVM-defined.

Adjust/add comments to kvm_only_cpuid_leafs and KVM_X86_FEATURE to
document how to create new kvm_only_cpuid_leafs entries for scattered
features as well as features that are entirely unknown to the kernel.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221125125845.1182922-3-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Quanxian Wang <quanxian.wang@intel.com>