x86/fpu: Add guest support to xfd_enable_feature()

Guest support for dynamically enabled FPU features requires a few
modifications to the enablement function which is currently invoked from
the #NM handler:

  1) Use guest permissions and sizes for the update

  2) Update fpu_guest state accordingly

  3) Take into account that the enabling can be triggered either from a
     running guest via XSETBV and MSR_IA32_XFD write emulation or from
     a guest restore. In the latter case the guests fpstate is not the
     current tasks active fpstate.

Split the function and implement the guest mechanics throughout the
callchain.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Jing Liu <[email protected]>
Signed-off-by: Yang Zhong <[email protected]>
Message-Id: <[email protected]>
[Add 32-bit stub for __xfd_enable_feature. - Paolo]
Signed-off-by: Paolo Bonzini <[email protected]>

0 files changed, 0 insertions, 0 deletions