On 2021/1/19 下午10:53, Yuri Benditovich wrote:
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?
It means the configure will fail if libbpf is not installed. Consider
libbpf is not very common at current stage. I think it's better to make
it auto or disabled by default.
+ 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.
I mean the current can not be used without checking rss_is_loaded(). So
rss_is_loaded() is somehow a guard like macro.
I personally prefer #ifdef but it's not a must.
Thanks
