* ebpf/rss.bpf.skeleton.h generated by what?
@ 2022-05-06 12:25 Markus Armbruster
2022-05-07 5:05 ` Jason Wang
0 siblings, 1 reply; 13+ messages in thread
From: Markus Armbruster @ 2022-05-06 12:25 UTC (permalink / raw)
To: Andrew Melnychenko; +Cc: qemu-devel, Jason Wang
ebpf/rss.bpf.skeleton.h contains
/* THIS FILE IS AUTOGENERATED! */
If it was generated by something in the tree, it should not be committed
to git. Doesn't look like it is.
Perhaps it was copied from elsewhere, but the commit message offers no
clue.
Please advise.
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-06 12:25 ebpf/rss.bpf.skeleton.h generated by what? Markus Armbruster @ 2022-05-07 5:05 ` Jason Wang 2022-05-07 6:46 ` Paolo Bonzini 0 siblings, 1 reply; 13+ messages in thread From: Jason Wang @ 2022-05-07 5:05 UTC (permalink / raw) To: Markus Armbruster; +Cc: Andrew Melnychenko, qemu-devel On Fri, May 6, 2022 at 8:26 PM Markus Armbruster <armbru@redhat.com> wrote: > > ebpf/rss.bpf.skeleton.h contains > > /* THIS FILE IS AUTOGENERATED! */ > > If it was generated by something in the tree, it should not be committed > to git. Doesn't look like it is. Andrew may know more. I remember it was generated by libbpf. Thanks > > Perhaps it was copied from elsewhere, but the commit message offers no > clue. > > Please advise. > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-07 5:05 ` Jason Wang @ 2022-05-07 6:46 ` Paolo Bonzini 2022-05-07 6:53 ` Jason Wang 0 siblings, 1 reply; 13+ messages in thread From: Paolo Bonzini @ 2022-05-07 6:46 UTC (permalink / raw) To: Jason Wang, Markus Armbruster; +Cc: Andrew Melnychenko, qemu-devel On 5/7/22 07:05, Jason Wang wrote: >> If it was generated by something in the tree, it should not be committed >> to git. Doesn't look like it is. > Andrew may know more. > > I remember it was generated by libbpf. What is the source? Paolo ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-07 6:46 ` Paolo Bonzini @ 2022-05-07 6:53 ` Jason Wang 2022-05-07 6:58 ` Paolo Bonzini 0 siblings, 1 reply; 13+ messages in thread From: Jason Wang @ 2022-05-07 6:53 UTC (permalink / raw) To: Paolo Bonzini; +Cc: Markus Armbruster, Andrew Melnychenko, qemu-devel On Sat, May 7, 2022 at 2:46 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > > On 5/7/22 07:05, Jason Wang wrote: > >> If it was generated by something in the tree, it should not be committed > >> to git. Doesn't look like it is. > > Andrew may know more. > > > > I remember it was generated by libbpf. > > What is the source? It's tools/ebpf/rss.bpf.c. Thanks > > Paolo > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-07 6:53 ` Jason Wang @ 2022-05-07 6:58 ` Paolo Bonzini 2022-05-07 7:08 ` Jason Wang 0 siblings, 1 reply; 13+ messages in thread From: Paolo Bonzini @ 2022-05-07 6:58 UTC (permalink / raw) To: Jason Wang; +Cc: Markus Armbruster, Andrew Melnychenko, qemu-devel On 5/7/22 08:53, Jason Wang wrote: > On Sat, May 7, 2022 at 2:46 PM Paolo Bonzini <pbonzini@redhat.com> wrote: >> >> On 5/7/22 07:05, Jason Wang wrote: >>>> If it was generated by something in the tree, it should not be committed >>>> to git. Doesn't look like it is. >>> Andrew may know more. >>> >>> I remember it was generated by libbpf. >> >> What is the source? > > It's tools/ebpf/rss.bpf.c. Thanks, maybe we can reuse some of the support for cross compilation that will be introduced soon. Paolo ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-07 6:58 ` Paolo Bonzini @ 2022-05-07 7:08 ` Jason Wang 2022-05-09 5:27 ` Markus Armbruster 0 siblings, 1 reply; 13+ messages in thread From: Jason Wang @ 2022-05-07 7:08 UTC (permalink / raw) To: Paolo Bonzini; +Cc: Markus Armbruster, Andrew Melnychenko, qemu-devel On Sat, May 7, 2022 at 2:58 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > > On 5/7/22 08:53, Jason Wang wrote: > > On Sat, May 7, 2022 at 2:46 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > >> > >> On 5/7/22 07:05, Jason Wang wrote: > >>>> If it was generated by something in the tree, it should not be committed > >>>> to git. Doesn't look like it is. > >>> Andrew may know more. > >>> > >>> I remember it was generated by libbpf. > >> > >> What is the source? > > > > It's tools/ebpf/rss.bpf.c. > > Thanks, maybe we can reuse some of the support for cross compilation > that will be introduced soon. That would be better. The reason we don't auto generate during make is to avoid adding new dependencies (where libbpf/bpftool is not popular at that time). Thanks > > Paolo > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-07 7:08 ` Jason Wang @ 2022-05-09 5:27 ` Markus Armbruster 2022-05-09 6:52 ` Jason Wang 2022-05-09 8:41 ` Peter Maydell 0 siblings, 2 replies; 13+ messages in thread From: Markus Armbruster @ 2022-05-09 5:27 UTC (permalink / raw) To: Jason Wang; +Cc: Paolo Bonzini, Andrew Melnychenko, qemu-devel Jason Wang <jasowang@redhat.com> writes: > On Sat, May 7, 2022 at 2:58 PM Paolo Bonzini <pbonzini@redhat.com> wrote: >> >> On 5/7/22 08:53, Jason Wang wrote: >> > On Sat, May 7, 2022 at 2:46 PM Paolo Bonzini <pbonzini@redhat.com> wrote: >> >> >> >> On 5/7/22 07:05, Jason Wang wrote: >> >>>> If it was generated by something in the tree, it should not be committed >> >>>> to git. Doesn't look like it is. >> >>> Andrew may know more. >> >>> >> >>> I remember it was generated by libbpf. >> >> >> >> What is the source? >> > >> > It's tools/ebpf/rss.bpf.c. Aha: $ cat tools/ebpf/Makefile.ebpf [...] $(OBJS): %.o:%.c $(CLANG) $(INC_FLAGS) \ -D__KERNEL__ -D__ASM_SYSREG_H \ -I../include $(LINUXINCLUDE) \ $(EXTRA_CFLAGS) -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@ bpftool gen skeleton rss.bpf.o > rss.bpf.skeleton.h ---> cp rss.bpf.skeleton.h ../../ebpf/ and $ cat docs/devel/ebpf_rss.rst [...] RSS eBPF program ---------------- RSS program located in ebpf/rss.bpf.skeleton.h generated by bpftool. So the program is part of the qemu binary. Initially, the eBPF program was compiled by clang and source code located at tools/ebpf/rss.bpf.c. Prerequisites to recompile the eBPF program (regenerate ebpf/rss.bpf.skeleton.h): llvm, clang, kernel source tree, bpftool Adjust Makefile.ebpf to reflect the location of the kernel source tree $ cd tools/ebpf $ make -f Makefile.ebpf [...] Together, this answers my "what" question. It doesn't answer my next question: why? That one gets answered ... >> Thanks, maybe we can reuse some of the support for cross compilation >> that will be introduced soon. > > That would be better. ... here: > The reason we don't auto generate during make is > to avoid adding new dependencies (where libbpf/bpftool is not popular > at that time). Always, always, *always* document your reasons for doing stuff right in the commit message, unless they are blindingly obvious. I understand reasons can be obvious enough to the author. Document them anyway if there is any chance they are not obvious to others. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-09 5:27 ` Markus Armbruster @ 2022-05-09 6:52 ` Jason Wang 2022-05-09 8:41 ` Peter Maydell 1 sibling, 0 replies; 13+ messages in thread From: Jason Wang @ 2022-05-09 6:52 UTC (permalink / raw) To: Markus Armbruster; +Cc: Paolo Bonzini, Andrew Melnychenko, qemu-devel On Mon, May 9, 2022 at 1:27 PM Markus Armbruster <armbru@redhat.com> wrote: > > Jason Wang <jasowang@redhat.com> writes: > > > On Sat, May 7, 2022 at 2:58 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > >> > >> On 5/7/22 08:53, Jason Wang wrote: > >> > On Sat, May 7, 2022 at 2:46 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > >> >> > >> >> On 5/7/22 07:05, Jason Wang wrote: > >> >>>> If it was generated by something in the tree, it should not be committed > >> >>>> to git. Doesn't look like it is. > >> >>> Andrew may know more. > >> >>> > >> >>> I remember it was generated by libbpf. > >> >> > >> >> What is the source? > >> > > >> > It's tools/ebpf/rss.bpf.c. > > Aha: > > $ cat tools/ebpf/Makefile.ebpf > [...] > $(OBJS): %.o:%.c > $(CLANG) $(INC_FLAGS) \ > -D__KERNEL__ -D__ASM_SYSREG_H \ > -I../include $(LINUXINCLUDE) \ > $(EXTRA_CFLAGS) -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@ > bpftool gen skeleton rss.bpf.o > rss.bpf.skeleton.h > ---> cp rss.bpf.skeleton.h ../../ebpf/ > > and > > $ cat docs/devel/ebpf_rss.rst > [...] > RSS eBPF program > ---------------- > > RSS program located in ebpf/rss.bpf.skeleton.h generated by bpftool. > So the program is part of the qemu binary. > Initially, the eBPF program was compiled by clang and source code located at tools/ebpf/rss.bpf.c. > Prerequisites to recompile the eBPF program (regenerate ebpf/rss.bpf.skeleton.h): > > llvm, clang, kernel source tree, bpftool > Adjust Makefile.ebpf to reflect the location of the kernel source tree > > $ cd tools/ebpf > $ make -f Makefile.ebpf > [...] > > Together, this answers my "what" question. It doesn't answer my next > question: why? That one gets answered ... > > >> Thanks, maybe we can reuse some of the support for cross compilation > >> that will be introduced soon. > > > > That would be better. > > ... here: > > > The reason we don't auto generate during make is > > to avoid adding new dependencies (where libbpf/bpftool is not popular > > at that time). > > Always, always, *always* document your reasons for doing stuff right in > the commit message, unless they are blindingly obvious. I understand > reasons can be obvious enough to the author. Document them anyway if > there is any chance they are not obvious to others. > Ok. Andrew, want to post a patch to explain this? Thanks ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-09 5:27 ` Markus Armbruster 2022-05-09 6:52 ` Jason Wang @ 2022-05-09 8:41 ` Peter Maydell 2022-05-09 9:35 ` Jason Wang 1 sibling, 1 reply; 13+ messages in thread From: Peter Maydell @ 2022-05-09 8:41 UTC (permalink / raw) To: Markus Armbruster Cc: Jason Wang, Paolo Bonzini, Andrew Melnychenko, qemu-devel On Mon, 9 May 2022 at 06:30, Markus Armbruster <armbru@redhat.com> wrote: > Always, always, *always* document your reasons for doing stuff right in > the commit message, unless they are blindingly obvious. I understand > reasons can be obvious enough to the author. Document them anyway if > there is any chance they are not obvious to others. It's also nice for code-generators to say who they are in this kind of "this file is autogenerated" comment. For instance our own decodetree script's comments read /* This file is autogenerated by scripts/decodetree.py. */ -- PMM ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-09 8:41 ` Peter Maydell @ 2022-05-09 9:35 ` Jason Wang 2022-05-10 12:15 ` Andrew Melnichenko 0 siblings, 1 reply; 13+ messages in thread From: Jason Wang @ 2022-05-09 9:35 UTC (permalink / raw) To: Peter Maydell Cc: Markus Armbruster, Paolo Bonzini, Andrew Melnychenko, qemu-devel On Mon, May 9, 2022 at 4:42 PM Peter Maydell <peter.maydell@linaro.org> wrote: > > On Mon, 9 May 2022 at 06:30, Markus Armbruster <armbru@redhat.com> wrote: > > Always, always, *always* document your reasons for doing stuff right in > > the commit message, unless they are blindingly obvious. I understand > > reasons can be obvious enough to the author. Document them anyway if > > there is any chance they are not obvious to others. > > It's also nice for code-generators to say who they are > in this kind of "this file is autogenerated" comment. > For instance our own decodetree script's comments read > /* This file is autogenerated by scripts/decodetree.py. */ Unfortunately, this is not what bpftool did right now. Have posted a patch (with Markus and you cced). Thanks > > -- PMM > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-09 9:35 ` Jason Wang @ 2022-05-10 12:15 ` Andrew Melnichenko 2022-05-11 8:53 ` Jason Wang 0 siblings, 1 reply; 13+ messages in thread From: Andrew Melnichenko @ 2022-05-10 12:15 UTC (permalink / raw) To: Jason Wang Cc: Peter Maydell, Markus Armbruster, Paolo Bonzini, qemu-devel, Yuri Benditovich, Yan Vugenfirer Hi all, The ebpf/rss.bpf.skeleton.h is generetad by bpftool from tools/ebpf/rss.bpf.c. To generate the skeleton - would require dependencies of llvm and bpftool. RSS eBPF solution, for now, is only for Linux hosts. > Andrew, want to post a patch to explain this? I am all in for clarification. And will prepare a new patch if required. Please advise, what those patches should be? Documentation update? On Mon, May 9, 2022 at 12:35 PM Jason Wang <jasowang@redhat.com> wrote: > > On Mon, May 9, 2022 at 4:42 PM Peter Maydell <peter.maydell@linaro.org> wrote: > > > > On Mon, 9 May 2022 at 06:30, Markus Armbruster <armbru@redhat.com> wrote: > > > Always, always, *always* document your reasons for doing stuff right in > > > the commit message, unless they are blindingly obvious. I understand > > > reasons can be obvious enough to the author. Document them anyway if > > > there is any chance they are not obvious to others. > > > > It's also nice for code-generators to say who they are > > in this kind of "this file is autogenerated" comment. > > For instance our own decodetree script's comments read > > /* This file is autogenerated by scripts/decodetree.py. */ > > Unfortunately, this is not what bpftool did right now. > > Have posted a patch (with Markus and you cced). > > Thanks > > > > > -- PMM > > > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-10 12:15 ` Andrew Melnichenko @ 2022-05-11 8:53 ` Jason Wang 2022-05-11 12:46 ` Markus Armbruster 0 siblings, 1 reply; 13+ messages in thread From: Jason Wang @ 2022-05-11 8:53 UTC (permalink / raw) To: Andrew Melnichenko Cc: Peter Maydell, Markus Armbruster, Paolo Bonzini, qemu-devel, Yuri Benditovich, Yan Vugenfirer On Tue, May 10, 2022 at 8:24 PM Andrew Melnichenko <andrew@daynix.com> wrote: > > Hi all, > The ebpf/rss.bpf.skeleton.h is generetad by bpftool from tools/ebpf/rss.bpf.c. > To generate the skeleton - would require dependencies of llvm and bpftool. > RSS eBPF solution, for now, is only for Linux hosts. > > > Andrew, want to post a patch to explain this? > I am all in for clarification. And will prepare a new patch if required. > Please advise, what those patches should be? Documentation update? It looks to me the doc are fine: """ RSS eBPF program ---------------- RSS program located in ebpf/rss.bpf.skeleton.h generated by bpftool. So the program is part of the qemu binary. Initially, the eBPF program was compiled by clang and source code located at tools/ebpf/rss.bpf.c. """ It was too late to fix the changelog but we probably don't have anything to do. Or we can update ebpf/rss.bpf.skeleton.h by using the most recent bpftool where I've added the BPFTOOL as the generator name[1]. Thanks [1] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=56c3e749d08a > > > On Mon, May 9, 2022 at 12:35 PM Jason Wang <jasowang@redhat.com> wrote: > > > > On Mon, May 9, 2022 at 4:42 PM Peter Maydell <peter.maydell@linaro.org> wrote: > > > > > > On Mon, 9 May 2022 at 06:30, Markus Armbruster <armbru@redhat.com> wrote: > > > > Always, always, *always* document your reasons for doing stuff right in > > > > the commit message, unless they are blindingly obvious. I understand > > > > reasons can be obvious enough to the author. Document them anyway if > > > > there is any chance they are not obvious to others. > > > > > > It's also nice for code-generators to say who they are > > > in this kind of "this file is autogenerated" comment. > > > For instance our own decodetree script's comments read > > > /* This file is autogenerated by scripts/decodetree.py. */ > > > > Unfortunately, this is not what bpftool did right now. > > > > Have posted a patch (with Markus and you cced). > > > > Thanks > > > > > > > > -- PMM > > > > > > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: ebpf/rss.bpf.skeleton.h generated by what? 2022-05-11 8:53 ` Jason Wang @ 2022-05-11 12:46 ` Markus Armbruster 0 siblings, 0 replies; 13+ messages in thread From: Markus Armbruster @ 2022-05-11 12:46 UTC (permalink / raw) To: Jason Wang Cc: Andrew Melnichenko, Peter Maydell, Paolo Bonzini, qemu-devel, Yuri Benditovich, Yan Vugenfirer Jason Wang <jasowang@redhat.com> writes: > On Tue, May 10, 2022 at 8:24 PM Andrew Melnichenko <andrew@daynix.com> wrote: >> >> Hi all, >> The ebpf/rss.bpf.skeleton.h is generetad by bpftool from tools/ebpf/rss.bpf.c. >> To generate the skeleton - would require dependencies of llvm and bpftool. >> RSS eBPF solution, for now, is only for Linux hosts. >> >> > Andrew, want to post a patch to explain this? >> I am all in for clarification. And will prepare a new patch if required. >> Please advise, what those patches should be? Documentation update? > > It looks to me the doc are fine: > > """ > RSS eBPF program > ---------------- > > RSS program located in ebpf/rss.bpf.skeleton.h generated by bpftool. > So the program is part of the qemu binary. > Initially, the eBPF program was compiled by clang and source code > located at tools/ebpf/rss.bpf.c. > """ Agreed. > It was too late to fix the changelog but we probably don't have anything to do. Next time :) > Or we can update ebpf/rss.bpf.skeleton.h by using the most recent > bpftool where I've added the BPFTOOL as the generator name[1]. Won't hurt, but no rush. > Thanks > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=56c3e749d08a ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2022-05-11 12:52 UTC | newest] Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-05-06 12:25 ebpf/rss.bpf.skeleton.h generated by what? Markus Armbruster 2022-05-07 5:05 ` Jason Wang 2022-05-07 6:46 ` Paolo Bonzini 2022-05-07 6:53 ` Jason Wang 2022-05-07 6:58 ` Paolo Bonzini 2022-05-07 7:08 ` Jason Wang 2022-05-09 5:27 ` Markus Armbruster 2022-05-09 6:52 ` Jason Wang 2022-05-09 8:41 ` Peter Maydell 2022-05-09 9:35 ` Jason Wang 2022-05-10 12:15 ` Andrew Melnichenko 2022-05-11 8:53 ` Jason Wang 2022-05-11 12:46 ` Markus Armbruster
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