11:36 a.m.
Hi all,
On Fri, May 17, 2024 at 5:00 PM Michal Prívozník <mprivozn(a)redhat.com> wrote:
On 5/12/24 21:45, Andrew Melnychenko wrote:
> Also, added dependencies for libbpf with bpf option.
>
> Signed-off-by: Andrew Melnychenko <andrew(a)daynix.com>
> ---
> meson.build | 7 ++++
> meson_options.txt | 1 +
> src/qemu/meson.build | 1 +
> src/qemu/qemu_interface.c | 83 +++++++++++++++++++++++++++++++++++++++
> src/qemu/qemu_interface.h | 4 ++
> 5 files changed, 96 insertions(+)
libvirt.spec.in should be changed too to either selectively disable this
feature or enable it and drag in the requirement (preferred).
Yes, I'll "enable it" in the next version.
>
> diff --git a/meson.build b/meson.build
> index e8b0094b91..e12a703a4d 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -998,6 +998,12 @@ else
> libkvm_dep = dependency('', required: false)
> endif
>
> +libbpf_version = '1.1.0'
> +libbpf_dep = dependency('libbpf', version: '>=' +
libbpf_version, required: get_option('libbpf'))
> +if libbpf_dep.found()
> + conf.set('WITH_BPF', 1)
> +endif
> +
> libiscsi_version = '1.18.0'
> libiscsi_dep = dependency('libiscsi', version: '>=' +
libiscsi_version, required: get_option('libiscsi'))
>
> @@ -2283,6 +2289,7 @@ libs_summary = {
> 'dlopen': dlopen_dep.found(),
> 'fuse': fuse_dep.found(),
> 'glusterfs': glusterfs_dep.found(),
> + 'libbpf': libbpf_dep.found(),
> 'libiscsi': libiscsi_dep.found(),
> 'libkvm': libkvm_dep.found(),
> 'libnbd': libnbd_dep.found(),
> diff --git a/meson_options.txt b/meson_options.txt
> index 9d729b3e1f..9b7bd9d1f8 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -48,6 +48,7 @@ option('udev', type: 'feature', value:
'auto', description: 'udev support')
> option('wireshark_dissector', type: 'feature', value:
'auto', description: 'wireshark support')
> option('wireshark_plugindir', type: 'string', value: '',
description: 'wireshark plugins directory for use when installing wireshark
plugin')
> option('yajl', type: 'feature', value: 'auto', description:
'yajl support')
> +option('libbpf', type: 'feature', value: 'auto',
description: 'qemu libbpf support')
>
>
> # build driver options
> diff --git a/src/qemu/meson.build b/src/qemu/meson.build
> index 907893d431..de7ae87d5b 100644
> --- a/src/qemu/meson.build
> +++ b/src/qemu/meson.build
> @@ -105,6 +105,7 @@ if conf.has('WITH_QEMU')
> selinux_dep,
> src_dep,
> xdr_dep,
> + libbpf_dep,
We tend to keep this kind of lists sorted alphabetically.
> ],
> include_directories: [
> conf_inc_dir,
> diff --git a/src/qemu/qemu_interface.c b/src/qemu/qemu_interface.c
> index c2007c7043..ec8cf18d86 100644
> --- a/src/qemu/qemu_interface.c
> +++ b/src/qemu/qemu_interface.c
> @@ -38,6 +38,10 @@
> #include <sys/stat.h>
> #include <fcntl.h>
>
> +#ifdef WITH_BPF
> +#include <bpf/libbpf.h>
s/#include/# include/
if you'd install 'cppi' then a syntax-check rule of ours would have
warned you about this.
> +#endif
> +
> #define VIR_FROM_THIS VIR_FROM_QEMU
>
> VIR_LOG_INIT("qemu.qemu_interface");
> @@ -432,3 +436,82 @@ qemuInterfaceOpenVhostNet(virDomainObj *vm,
> virDomainAuditNetDevice(vm->def, net, vhostnet_path, vhostfdSize);
> return 0;
> }
> +
> +#ifdef WITH_BPF
> +
> +int
> +qemuInterfaceLoadEbpf(const char *ebpfObject, void **retLibbpfObj, int *fds, size_t
nfds)
> +{
> + int err = 0;
> + size_t i = 0;
> + struct bpf_program *prog;
> + struct bpf_map *map;
> + struct bpf_object *obj;
> + size_t ebpfSize = 0;
> + g_autofree void *ebpfRawData = NULL;
> +
> + ebpfRawData = g_base64_decode(ebpfObject, &ebpfSize);
> + if (ebpfRawData == NULL) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("can't
decode the eBPF from base64"));
> + return -1;
> + }
> +
> + obj = bpf_object__open_mem(ebpfRawData, ebpfSize, NULL);
> + err = libbpf_get_error(obj);
> + if (err) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("can't
open eBPF object"));
> + return -1;
> + }
IIUC, libbpf_get_error() is deprecated and upon failure bpf_object_*()
APIs return NULL and set errno. Thus this (and the rest) could look
something like this:
obj = bpf_object__open_mem(...);
if (!obj) {
virReportSystemError(errno, "%s", _("can't open eBPF
object"));
return -1;
}
Ok. originally I've tied to omit errno and use VIR_ERR* macros.
> +
> +
> + err = bpf_object__load(obj);
> + if (err) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("can't
load eBPF object"));
> + return -1;
> + }
> +
> + bpf_object__for_each_program(prog, obj) {
> + fds[i] = bpf_program__fd(prog);
> + ++i;
> + if (i > nfds) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("to much
file descriptors in eBPF"));
> + return -1;
> + }
> + }
> +
> + bpf_object__for_each_map(map, obj) {
> + fds[i] = bpf_map__fd(map);
> + ++i;
> + if (i > nfds) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("to much
file descriptors in eBPF"));
> + return -1;
> + }
> + }
> +
> + *retLibbpfObj = obj;
> +
> + return i - 1;
> +}
> +
> +
> +void
> +qemuInterfaceCloseEbpf(void *libbpfObj)
> +{
> + if (libbpfObj)
> + bpf_object__close(libbpfObj);
> +}
> +#else
> +
> +int
> +qemuInterfaceLoadEbpf(const char *ebpfObject G_GNUC_UNUSED, void **retLibbpfObj
G_GNUC_UNUSED,
> + int *fds G_GNUC_UNUSED, size_t nfds G_GNUC_UNUSED)
> +{
> + return -1;
Maybe this can return -2 so that callers can distinguish this version
and the version above failing?
Ok.
> > +}
>
> Michal
>