On 8/3/21 4:29 PM, Pavel Hrdina wrote:
Based on kernel commit messages the interface is
/sys/class/fc/fc_udev_device/appid_store
where we need to write the following string "$INODE:$VMID".
$INODE is the VM root cgroup inode in hexadecimal and $VMID is user provided string that will be attached to each FC frame for the VM within the cgroup identified by inode and has limit 128 bytes.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com> --- src/qemu/qemu_cgroup.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index f2d99abcfa..df021b5985 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -904,6 +904,35 @@ qemuSetupCpuCgroup(virDomainObj *vm) }
+static int +qemuSetupCgroupVMID(virDomainObj *vm) +{ + qemuDomainObjPrivate *priv = vm->privateData; + int inode = virCgroupGetInode(priv->cgroup); + const char *path = "/sys/class/fc/fc_udev_device/appid_store"; + g_autofree char *appid = NULL; + + if (!vm->def->vmid) + return 0; + + appid = g_strdup_printf("%X:%s", inode, vm->def->vmid); + + if (virFileWriteStr(path, appid, 0) < 0) { + if (errno == ENOENT) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("FC VMID not available on this host")); + return -1; + } + + virReportSystemError(errno, + _("Unable to write '%s' to '%s'"), appid, path);
Alternatively, use the following pattern: if (errno == ENOENT) { virReportError(); } else { virReportSystemError(); } return -1; Or use just virReportSystemError(); I believe "Unable to write to /sys/class/...: No such file or directory" is pretty comprehensive. Michal