Re: [Xen-devel] [PATCH 1/4] xen: build infrastructure for generating hypercall depending symbols

David Vrabel
2014-12-15T11:38:46Z

On 11/12/14 18:04, Juergen Gross wrote:
> Today there are several places in the kernel which build tables
> containing one entry for each possible Xen hypercall. Create an
> infrastructure to be able to generate these tables at build time.

Does arm and arm64 need something similar? If so are the tools here
suitable for them?

> --- a/arch/x86/syscalls/Makefile
> +++ b/arch/x86/syscalls/Makefile

Why are these changes here and not in arch/x86/xen/Makefile?

> @@ -19,6 +19,9 @@ quiet_cmd_syshdr = SYSHDR $@
> quiet_cmd_systbl = SYSTBL $@
> cmd_systbl = $(CONFIG_SHELL) '$(systbl)' $< $@
>
> +quiet_cmd_hypercalls = HYPERCALLS $@
> + cmd_hypercalls = $(CONFIG_SHELL) '$<' $@ $(filter-out $<,$^)
> +
> syshdr_abi_unistd_32 := i386
> $(uapi)/unistd_32.h: $(syscall32) $(syshdr)
> $(call if_changed,syshdr)
> @@ -47,10 +50,16 @@ $(out)/syscalls_32.h: $(syscall32) $(systbl)
> $(out)/syscalls_64.h: $(syscall64) $(systbl)
> $(call if_changed,systbl)
>
> +$(out)/xen-hypercalls.h: $(srctree)/scripts/xen-hypercalls.sh
> + $(call if_changed,hypercalls)
> +
> +$(out)/xen-hypercalls.h: $(srctree)/include/xen/interface/xen*.h

The generated header should end up in asm/xen/

> --- /dev/null
> +++ b/scripts/xen-hypercalls.sh
> @@ -0,0 +1,11 @@
> +#!/bin/sh
> +out="$1"
> +shift
> +in="$@"
> +
> +for i in $in; do
> + eval $CPP $LINUXINCLUDE -dD -imacros "$i" -x c /dev/null
> +done | \
> +awk '$1 == "#define" && $2 ~ /__HYPERVISOR_[a-z][a-z_0-9]*/ { v[$3] = $2 }
> + END {for (i in v) if (!(v[i] in v))
> + print "HYPERCALL("substr(v[i], 14)")"}' | sort -u >$out

Include a comment in the generated output saying what generated it. e.g.,

/* auto-generated by scripts/xen-hypercall.sh */

David