kvm: x86: Add emulation for IA32_XFD

mainline inclusion
from mainline-v5.17-rc1
commit 820a6ee9
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RQLJ


CVE: NA

Intel-SIG: commit 820a6ee9 kvm: x86: Add emulation for IA32_XFD.

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

Intel's eXtended Feature Disable (XFD) feature allows the software
to dynamically adjust fpstate buffer size for XSAVE features which
have large state.

Because guest fpstate has been expanded for all possible dynamic
xstates at KVM_SET_CPUID2, emulation of the IA32_XFD MSR is
straightforward. For write just call fpu_update_guest_xfd() to
update the guest fpu container once all the sanity checks are passed.
For read simply return the cached value in the container.

Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20220105123532.12586-11-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lin Wang <lin.x.wang@intel.com>