[libvirt] [PATCH 05/19] vircgroup: introduce virCgroupV2DeviceDetectProg
This function will be called if libvirtd was restarted while some
domains were running. It will try to detect existing programs attached
to the guest cgroup.
Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com>
---
src/util/vircgroupv2.c | 105 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 105 insertions(+)
diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c
index 7a8cc040eb..86adbc4ff9 100644
--- a/src/util/vircgroupv2.c
+++ b/src/util/vircgroupv2.c
@@ -1723,6 +1723,111 @@ virCgroupV2DeviceAttachProg(virCgroupPtr group,
}
+static int
+virCgroupV2DeviceCountMapEntries(int mapfd)
+{
+ int ret = 0;
+ int rc;
+ __u64 key = 0;
+ __u64 prevKey = 0;
+
+ while ((rc = virBPFGetNextElem(mapfd, &prevKey, &key)) == 0) {
+ ret++;
+ prevKey = key;
+ }
+
+ if (rc < 0)
+ return -1;
+
+ return ret;
+}
+
+
+# define MAX_PROG_IDS 10
+
+static int
+virCgroupV2DeviceDetectProg(virCgroupPtr group)
+{
+ int ret = -1;
+ int cgroupfd = -1;
+ unsigned int progcnt = 0;
+ unsigned int progids[MAX_PROG_IDS] = { 0 };
+ VIR_AUTOFREE(char *) path = NULL;
+
+ if (group->unified.devices.progfd > 0 &&
group->unified.devices.mapfd > 0)
+ return 0;
+
+ if (virCgroupV2PathOfController(group, VIR_CGROUP_CONTROLLER_DEVICES,
+ NULL, &path) < 0) {
+ return -1;
+ }
+
+ cgroupfd = open(path, O_RDONLY);
+ if (cgroupfd < 0) {
+ virReportSystemError(errno, _("unable to open '%s'"), path);
+ goto cleanup;
+ }
+
+ if (virBPFQueryProg(cgroupfd, MAX_PROG_IDS, BPF_CGROUP_DEVICE,
+ &progcnt, progids) < 0) {
+ virReportSystemError(errno, "%s", _("unable to query cgroup BPF
progs"));
+ goto cleanup;
+ }
+
+ if (progcnt > 0) {
+ int progfd = virBPFGetProg(progids[0]);
+ int mapfd = -1;
+ int nitems = -1;
+ struct bpf_prog_info progInfo = { 0 };
+ struct bpf_map_info mapInfo = { 0 };
+ VIR_AUTOFREE(unsigned int *) mapIDs = NULL;
+
+ if (progfd < 0) {
+ virReportSystemError(errno, "%s", _("failed to get cgroup BPF
prog FD"));
+ goto cleanup;
+ }
+
+ if (virBPFGetProgInfo(progfd, &progInfo, &mapIDs) < 0) {
+ virReportSystemError(errno, "%s", _("failed to get cgroup BPF
prog info"));
+ goto cleanup;
+ }
+
+ if (progInfo.nr_map_ids == 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("no map for cgroup BPF prog"));
+ goto cleanup;
+ }
+
+ mapfd = virBPFGetMap(mapIDs[0]);
+ if (mapfd < 0) {
+ virReportSystemError(errno, "%s", _("failed to get cgroup BPF
map FD"));
+ goto cleanup;
+ }
+
+ if (virBPFGetMapInfo(mapfd, &mapInfo) < 0) {
+ virReportSystemError(errno, "%s", _("failed to get cgroup BPF
map info"));
+ goto cleanup;
+ }
+
+ nitems = virCgroupV2DeviceCountMapEntries(mapfd);
+ if (nitems < 0) {
+ virReportSystemError(errno, "%s", _("failed to count cgroup
BPF map items"));
+ goto cleanup;
+ }
+
+ group->unified.devices.progfd = progfd;
+ group->unified.devices.mapfd = mapfd;
+ group->unified.devices.max = mapInfo.max_entries;
+ group->unified.devices.count = nitems;
+ }
+
+ ret = 0;
+ cleanup:
+ VIR_FORCE_CLOSE(cgroupfd);
+ return ret;
+}
+
+
virCgroupBackend virCgroupV2Backend = {
.type = VIR_CGROUP_BACKEND_TYPE_V2,
--
2.20.1