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@xxxxxxxxxx> --- 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); + return -1; + } + + return 0; +} + + static int qemuInitCgroup(virDomainObj *vm, size_t nnicindexes, @@ -1096,6 +1125,9 @@ qemuSetupCgroup(virDomainObj *vm, if (qemuSetupCpusetCgroup(vm) < 0) return -1; + if (qemuSetupCgroupVMID(vm) < 0) + return -1; + return 0; } -- 2.31.1