Trivial change, except for x86 virtualisation and bootup.
Normally the seL4_TCBFlag_fpuDisabled flag is used to decide whether
to enable or disable the FPU. However, with x86 virtualisation there
is only one TCB. Use the task flag for the host and always enable FPU
for the guest.
When either the host or the guest's FPU is loaded, ksCurFPUOwner will
point to our TCB. saveFpuState and loadFpuState check fpu_active and
do the right thing depending on the current FPU user. To make this
work it was necessary to pass tcb_t to saveFpuState and loadFpuState.
Use the idle thread to store the initial FPU state. x86KSnullFpuState
is kept to simplify verification.
However, when Arch_initFpu is called, the idle thread hasn't been
created yet, so move the initialisation to after create_idle_thread,
but before create_initial_thread, as that leads to Arch_initFpuContext
using x86KSnullFpuState.
Also initialise VCPU FPU registers correctly for x86, otherwise the
initial state is wrong and can't be loaded when XSAVES is enabled.
Signed-off-by: Indan Zupancic <indan@nul.nu>
1bd0e3b788