KVM: x86/cpuid: Clear XFD for component i if the base feature is missing

mainline inclusion
from mainline-v5.17-rc1
commit e9737468
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RQLJ


CVE: NA

Intel-SIG: commit e9737468 KVM: x86/cpuid: Clear XFD for component i if the base feature is missing.

--------------------------------

According to Intel extended feature disable (XFD) spec, the sub-function i
(i > 1) of CPUID function 0DH enumerates "details for state component i.
ECX[2] enumerates support for XFD support for this state component."

If KVM does not report F(XFD) feature (e.g. due to CONFIG_X86_64),
then the corresponding XFD support for any state component i
should also be removed. Translate this dependency into KVM terms.

Fixes: 690a757d ("kvm: x86: Add CPUID support for Intel AMX")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220117074531.76925-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lin Wang <lin.x.wang@intel.com>