On Fri, Jan 15, 2021 at 9:02 AM Jason Wang <jasow...@redhat.com> wrote:
>
>
> On 2021/1/15 上午5:16, Andrew Melnychenko wrote:
> > From: Andrew <and...@daynix.com>
> >
> > Added function that loads RSS eBPF program.
> > Added stub functions for RSS eBPF loader.
> > Added meson and configuration options.
> >
> > By default, eBPF feature enabled if libbpf is present in the build system.
> > libbpf checked in configuration shell script and meson script.
> >
> > Signed-off-by: Yuri Benditovich <yuri.benditov...@daynix.com>
> > Signed-off-by: Andrew Melnychenko <and...@daynix.com>
> > ---
> > configure | 33 ++++
> > ebpf/ebpf_rss-stub.c | 40 ++++
> > ebpf/ebpf_rss.c | 165 +++++++++++++++++
> > ebpf/ebpf_rss.h | 44 +++++
> > ebpf/meson.build | 1 +
> > ebpf/rss.bpf.skeleton.h | 397 ++++++++++++++++++++++++++++++++++++++++
> > ebpf/trace-events | 4 +
> > ebpf/trace.h | 2 +
> > meson.build | 13 ++
> > 9 files changed, 699 insertions(+)
> > create mode 100644 ebpf/ebpf_rss-stub.c
> > create mode 100644 ebpf/ebpf_rss.c
> > create mode 100644 ebpf/ebpf_rss.h
> > create mode 100644 ebpf/meson.build
> > create mode 100644 ebpf/rss.bpf.skeleton.h
> > create mode 100644 ebpf/trace-events
> > create mode 100644 ebpf/trace.h
> >
> > diff --git a/configure b/configure
> > index 5860bdb77b..9d18e941f5 100755
> > --- a/configure
> > +++ b/configure
> > @@ -342,6 +342,7 @@ vhost_vsock="$default_feature"
> > vhost_user="no"
> > vhost_user_blk_server="auto"
> > vhost_user_fs="$default_feature"
> > +bpf=""
> > kvm="auto"
> > hax="auto"
> > hvf="auto"
> > @@ -1236,6 +1237,10 @@ for opt do
> > ;;
> > --enable-membarrier) membarrier="yes"
> > ;;
> > + --disable-bpf) bpf="no"
> > + ;;
> > + --enable-bpf) bpf="yes"
> > + ;;
> > --disable-blobs) blobs="false"
> > ;;
> > --with-pkgversion=*) pkgversion="$optarg"
> > @@ -1845,6 +1850,7 @@ disabled with --disable-FEATURE, default is enabled
> > if available
> > vhost-user vhost-user backend support
> > vhost-user-blk-server vhost-user-blk server support
> > vhost-vdpa vhost-vdpa kernel backend support
> > + bpf BPF kernel support
> > spice spice
> > rbd rados block device (rbd)
> > libiscsi iscsi support
> > @@ -5057,6 +5063,30 @@ else
> > membarrier=no
> > fi
> >
> > +##########################################
> > +# check for usable bpf system call
> > +if test "$bpf" = ""; then
>
>
> This implies the bpf is enabled by default?
Yes, assuming libbpf-devel present and bpf system call defined.
Any problem with it?
>
>
> > + have_bpf=no
> > + if test "$linux" = "yes" -a "$bigendian" != "yes"; then
> > + cat > $TMPC << EOF
> > + #include <stdlib.h>
> > + #include <bpf/libbpf.h>
> > + int main(void) {
> > + struct bpf_object *obj = NULL;
> > + bpf_object__load(obj);
> > + exit(0);
> > + }
> > +EOF
> > + if compile_prog "" "-lbpf" ; then
> > + have_bpf=yes
> > + bpf=yes
> > + fi
> > + fi
> > + if test "$have_bpf" = "no"; then
> > + feature_not_found "bpf" "the libbpf is not available"
> > + fi
> > +fi
> > +
> > ##########################################
> > # check if rtnetlink.h exists and is useful
> > have_rtnetlink=no
> > @@ -5905,6 +5935,9 @@ fi
> > if test "$membarrier" = "yes" ; then
> > echo "CONFIG_MEMBARRIER=y" >> $config_host_mak
> > fi
> > +if test "$bpf" = "yes" -a "$bigendian" != "yes" -a "$linux" = "yes" ; then
> > + echo "CONFIG_EBPF=y" >> $config_host_mak
> > +fi
> > if test "$signalfd" = "yes" ; then
> > echo "CONFIG_SIGNALFD=y" >> $config_host_mak
> > fi
> > diff --git a/ebpf/ebpf_rss-stub.c b/ebpf/ebpf_rss-stub.c
> > new file mode 100644
> > index 0000000000..e71e229190
> > --- /dev/null
> > +++ b/ebpf/ebpf_rss-stub.c
> > @@ -0,0 +1,40 @@
> > +/*
> > + * eBPF RSS stub file
> > + *
> > + * Developed by Daynix Computing LTD (http://www.daynix.com)
> > + *
> > + * Authors:
> > + * Yuri Benditovich <yuri.benditov...@daynix.com>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2. See
> > + * the COPYING file in the top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "ebpf/ebpf_rss.h"
>
>
> I wonder why not simply use #ifdef #else to exclude the rss functions.
Just to make the reading easier.
>
> If I read code correctly, this stub requires rss_is_loaded called before
> ebpf_rss_set_all(), so actually ebpf_rss_is_loaded serve the same as
Can you please get into details?
I think the stub does not require it, it just converts all the
ebpf_rss calls to nop at link time.
If I miss something please let us know, we'll fix it in v4.
>
>
> > +
> > +void ebpf_rss_init(struct EBPFRSSContext *ctx)
> > +{
> > +
> > +}
> > +
> > +bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
> > +{
> > + return false;
> > +}
> > +
> > +bool ebpf_rss_load(struct EBPFRSSContext *ctx)
> > +{
> > + return false;
> > +}
> > +
> > +bool ebpf_rss_set_all(struct EBPFRSSContext *ctx, struct EBPFRSSConfig
> > *config,
> > + uint16_t *indirections_table, uint8_t *toeplitz_key)
> > +{
> > + return false;
> > +}
> > +
> > +void ebpf_rss_unload(struct EBPFRSSContext *ctx)
> > +{
> > +
> > +}
> > diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
> > new file mode 100644
> > index 0000000000..f7f7102da5
> > --- /dev/null
> > +++ b/ebpf/ebpf_rss.c
> > @@ -0,0 +1,165 @@
> > +/*
> > + * eBPF RSS loader
> > + *
> > + * Developed by Daynix Computing LTD (http://www.daynix.com)
> > + *
> > + * Authors:
> > + * Andrew Melnychenko <and...@daynix.com>
> > + * Yuri Benditovich <yuri.benditov...@daynix.com>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2. See
> > + * the COPYING file in the top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "qemu/error-report.h"
> > +
> > +#include <bpf/libbpf.h>
> > +#include <bpf/bpf.h>
> > +
> > +#include "hw/virtio/virtio-net.h" /* VIRTIO_NET_RSS_MAX_TABLE_LEN */
> > +
> > +#include "ebpf/ebpf_rss.h"
> > +#include "ebpf/rss.bpf.skeleton.h"
> > +#include "trace.h"
> > +
> > +void ebpf_rss_init(struct EBPFRSSContext *ctx)
> > +{
> > + if (ctx != NULL) {
> > + ctx->obj = NULL;
> > + }
> > +}
> > +
> > +bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
> > +{
> > + return ctx != NULL && ctx->obj != NULL;
> > +}
> > +
> > +bool ebpf_rss_load(struct EBPFRSSContext *ctx)
> > +{
> > + struct rss_bpf *rss_bpf_ctx;
> > +
> > + if (ctx == NULL) {
> > + return false;
> > + }
> > +
> > + rss_bpf_ctx = rss_bpf__open();
> > + if (rss_bpf_ctx == NULL) {
> > + trace_ebpf_error("eBPF RSS", "can not open eBPF RSS object");
> > + goto l_issue;
>
>
> Nit: it's not easy to infer what did "l" mean, it's probably better to
> use "error".
ok, will be renamed, 'l' means 'load' probably
>
> Thanks
>
