accel/hvf: Mention hvf_arch_init_vcpu() must run on vCPU thread

hvf_arch_init_vcpu(), along with hvf_put_guest_debug_registers()
and hvf_put_gdbstub_debug_registers(), calls hv_vcpu_set_sys_reg(),
which must run on a vCPU. Mention they also must.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Mads Ynddal <mads@ynddal.dk>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2 files changed