Hi all, On Fri, May 17, 2024 at 5:00 PM Michal Prívozník <mprivozn@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@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