On 31.10.2019 20:28, Andrew Cooper wrote: > This code is especially tangled. VCPUOP_initialise calls into > arch_initialise_vcpu() which calls back into default_initialise_vcpu() which > is common code. > > This path is actually dead code on ARM, because VCPUOP_initialise is filtered > out by do_arm_vcpu_op(). > > The only valid way to start a secondary CPU on ARM is via the PSCI interface. > The same could in principle be said about INIT-SIPI-SIPI for x86 HVM, if HVM > guests hadn't already interited a paravirt way of starting CPUs. > > Either way, it is quite likely that no future architectures implemented in Xen > are going to want to use a PV interface, as some standardised (v)CPU bringup > mechanism will already exist. > > Arrange the code in do_vcpu_op() to allow arch_initialise_vcpu() to be > optional. Opt in for x86, and opt out for ARM. > > Deleting ARM's arch_initialise_vcpu() allows for default_initialise_vcpu() to > be folded into its (now) sole x86 caller, which reduces the compiled code > volume in all builds. > > No functional change. > > Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
I can see the merits of this, but I can also understand Julien's reservations. Hence I guess whether to ack this will depend on the discussion with him getting settled. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
