On Sun, Oct 07, 2018 at 07:31:45PM -0700, Ori Bernstein wrote:
> Keep a list of known vms, and reuse the VM IDs. This means that when using
> '-L', the IP addresses of the VMs are stable.
>
After you conviced me about its use case, 3 comments:
1. it has to wait until after release
2. please following the naming vm_claimid instead of claim_vmid
3. you should bind it to name + vm_uid, not just name
I was actually wondering if we should use randomized non-linear vm ids
(e.g. with knuth shuffle) in the future, but that's a different topic
for a different time. This diff wouldn't conflict with it.
Reyk
> diff --git usr.sbin/vmd/config.c usr.sbin/vmd/config.c
> index af12b790002..522bae32501 100644
> --- usr.sbin/vmd/config.c
> +++ usr.sbin/vmd/config.c
> @@ -61,7 +61,10 @@ config_init(struct vmd *env)
> if (what & CONFIG_VMS) {
> if ((env->vmd_vms = calloc(1, sizeof(*env->vmd_vms))) == NULL)
> return (-1);
> + if ((env->vmd_known = calloc(1, sizeof(*env->vmd_known))) ==
> NULL)
> + return (-1);
> TAILQ_INIT(env->vmd_vms);
> + TAILQ_INIT(env->vmd_known);
> }
> if (what & CONFIG_SWITCHES) {
> if ((env->vmd_switches = calloc(1,
> diff --git usr.sbin/vmd/vmd.c usr.sbin/vmd/vmd.c
> index 18a5e0d3d5d..732691b4381 100644
> --- usr.sbin/vmd/vmd.c
> +++ usr.sbin/vmd/vmd.c
> @@ -1169,6 +1169,27 @@ vm_remove(struct vmd_vm *vm, const char *caller)
> free(vm);
> }
>
> +static uint32_t
> +claim_vmid(const char *name)
> +{
> + struct name2id *n2i = NULL;
> +
> + TAILQ_FOREACH(n2i, env->vmd_known, entry)
> + if (strcmp(n2i->name, name) == 0)
> + return n2i->id;
> +
> + if (++env->vmd_nvm == 0)
> + fatalx("too many vms");
> + if ((n2i = calloc(1, sizeof(struct name2id))) == NULL)
> + fatalx("could not alloc vm name");
> + n2i->id = env->vmd_nvm;
> + if (strlcpy(n2i->name, name, sizeof(n2i->name)) >= sizeof(n2i->name))
> + fatalx("overlong vm name");
> + TAILQ_INSERT_TAIL(env->vmd_known, n2i, entry);
> +
> + return n2i->id;
> +}
> +
> int
> vm_register(struct privsep *ps, struct vmop_create_params *vmc,
> struct vmd_vm **ret_vm, uint32_t id, uid_t uid)
> @@ -1300,11 +1321,8 @@ vm_register(struct privsep *ps, struct
> vmop_create_params *vmc,
> vm->vm_cdrom = -1;
> vm->vm_iev.ibuf.fd = -1;
>
> - if (++env->vmd_nvm == 0)
> - fatalx("too many vms");
> -
> /* Assign a new internal Id if not specified */
> - vm->vm_vmid = id == 0 ? env->vmd_nvm : id;
> + vm->vm_vmid = (id == 0) ? claim_vmid(vcp->vcp_name) : id;
>
> log_debug("%s: registering vm %d", __func__, vm->vm_vmid);
> TAILQ_INSERT_TAIL(env->vmd_vms, vm, vm_entry);
> diff --git usr.sbin/vmd/vmd.h usr.sbin/vmd/vmd.h
> index b7c012854e8..86fad536e59 100644
> --- usr.sbin/vmd/vmd.h
> +++ usr.sbin/vmd/vmd.h
> @@ -276,6 +276,13 @@ struct vmd_user {
> };
> TAILQ_HEAD(userlist, vmd_user);
>
> +struct name2id {
> + char name[VMM_MAX_NAME_LEN];
> + int32_t id;
> + TAILQ_ENTRY(name2id) entry;
> +};
> +TAILQ_HEAD(name2idlist, name2id);
> +
> struct address {
> struct sockaddr_storage ss;
> int prefixlen;
> @@ -300,6 +307,7 @@ struct vmd {
>
> uint32_t vmd_nvm;
> struct vmlist *vmd_vms;
> + struct name2idlist *vmd_known;
> uint32_t vmd_nswitches;
> struct switchlist *vmd_switches;
> struct userlist *vmd_users;
>
> --
> Ori Bernstein
--
