Add (partial) support for agentx in vmd.

Metrics can be found under mib-2.236 and VM-MIB (RFC7666).

Stress tested by and happy noises from Mischa Peters
OK dv@

7 files changed, 662 insertions, 17 deletions

diff --git a/usr.sbin/vmd/Makefile b/usr.sbin/vmd/Makefile
index 0abaf00fdd1..42e94fd394b 100644
--- a/usr.sbin/vmd/Makefile
+++ b/usr.sbin/vmd/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.26 2021/04/05 18:09:48 dv Exp $
+#	$OpenBSD: Makefile,v 1.27 2022/09/13 10:28:19 martijn Exp $
 
 .if ${MACHINE} == "amd64"
 
@@ -7,6 +7,7 @@ SRCS=		vmd.c control.c log.c priv.c proc.c config.c vmm.c
 SRCS+=		vm.c loadfile_elf.c pci.c virtio.c i8259.c mc146818.c
 SRCS+=		ns8250.c i8253.c dhcp.c packet.c
 SRCS+=		parse.y atomicio.c vioscsi.c vioraw.c vioqcow2.c fw_cfg.c
+SRCS+=		vm_agentx.c
 
 CFLAGS+=	-Wall -I${.CURDIR}
 CFLAGS+=	-Wstrict-prototypes -Wmissing-prototypes
@@ -14,8 +15,8 @@ CFLAGS+=	-Wmissing-declarations
 CFLAGS+=	-Wshadow -Wpointer-arith -Wcast-qual
 CFLAGS+=	-Wsign-compare
 
-LDADD+=		-lutil -lpthread -levent -lz
-DPADD+=		${LIBUTIL} ${LIBPTHREAD} ${LIBEVENT} ${LIBZ}
+LDADD+=		-lutil -lpthread -levent -lz -lagentx
+DPADD+=		${LIBUTIL} ${LIBPTHREAD} ${LIBEVENT} ${LIBZ} ${LIBAGENTX}
 
 YFLAGS=
 
diff --git a/usr.sbin/vmd/parse.y b/usr.sbin/vmd/parse.y
index f8aebbe039f..3175e17de51 100644
--- a/usr.sbin/vmd/parse.y
+++ b/usr.sbin/vmd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.61 2022/05/04 23:17:25 dv Exp $	*/
+/*	$OpenBSD: parse.y,v 1.62 2022/09/13 10:28:19 martijn Exp $	*/
 
 /*
  * Copyright (c) 2007-2016 Reyk Floeter <reyk@openbsd.org>
@@ -34,6 +34,7 @@
 #include <netinet/in.h>
 #include <netinet/if_ether.h>
 
+#include <agentx.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <limits.h>
@@ -119,7 +120,8 @@ typedef struct {
 
 
 %token	INCLUDE ERROR
-%token	ADD ALLOW BOOT CDROM DEVICE DISABLE DISK DOWN ENABLE FORMAT GROUP
+%token	ADD AGENTX ALLOW BOOT CDROM CONTEXT DEVICE DISABLE DISK DOWN ENABLE
+%token	FORMAT GROUP
 %token	INET6 INSTANCE INTERFACE LLADDR LOCAL LOCKED MEMORY NET NIFS OWNER
 %token	PATH PREFIX RDOMAIN SIZE SOCKET SWITCH UP VM VMID STAGGERED START
 %token  PARALLEL DELAY
@@ -217,6 +219,18 @@ main		: LOCAL INET6 {
 			env->vmd_ps.ps_csock.cs_uid = $3.uid;
 			env->vmd_ps.ps_csock.cs_gid = $3.gid == -1 ? 0 : $3.gid;
 		}
+		| AGENTX {
+			env->vmd_cfg.cfg_agentx.ax_enabled = 1;
+		} agentxopts {
+			if (env->vmd_cfg.cfg_agentx.ax_path[0] == '\0')
+				if (strlcpy(env->vmd_cfg.cfg_agentx.ax_path,
+				    AGENTX_MASTER_PATH,
+				    sizeof(env->vmd_cfg.cfg_agentx.ax_path)) >=
+				    sizeof(env->vmd_cfg.cfg_agentx.ax_path)) {
+					yyerror("invalid agentx path");
+					YYERROR;
+				}
+		}
 		| STAGGERED START PARALLEL NUMBER DELAY NUMBER {
 			env->vmd_cfg.cfg_flags |= VMD_CFG_STAGGERED_START;
 			env->vmd_cfg.delay.tv_sec = $6;
@@ -595,6 +609,35 @@ owner_id	: NUMBER		{
 		}
 		;
 
+agentxopt	: CONTEXT STRING {
+			if (strlcpy(env->vmd_cfg.cfg_agentx.ax_context, $2,
+			    sizeof(env->vmd_cfg.cfg_agentx.ax_context)) >=
+			    sizeof(env->vmd_cfg.cfg_agentx.ax_context)) {
+				yyerror("agentx context too large");
+				free($2);
+				YYERROR;
+			}
+			free($2);
+		}
+		| PATH STRING {
+			if (strlcpy(env->vmd_cfg.cfg_agentx.ax_path, $2,
+			    sizeof(env->vmd_cfg.cfg_agentx.ax_path)) >=
+			    sizeof(env->vmd_cfg.cfg_agentx.ax_path)) {
+				yyerror("agentx path too large");
+				free($2);
+				YYERROR;
+			}
+			free($2);
+			if (env->vmd_cfg.cfg_agentx.ax_path[0] != '/') {
+				yyerror("agentx path is not absolute");
+				YYERROR;
+			}
+		}
+
+agentxopts	: /* none */
+		| agentxopts agentxopt
+		;
+
 image_format	: /* none 	*/	{
 			$$ = 0;
 		}
@@ -769,9 +812,11 @@ lookup(char *s)
 	/* this has to be sorted always */
 	static const struct keywords keywords[] = {
 		{ "add",		ADD },
+		{ "agentx",		AGENTX },
 		{ "allow",		ALLOW },
 		{ "boot",		BOOT },
 		{ "cdrom",		CDROM },
+		{ "context",		CONTEXT},
 		{ "delay",		DELAY },
 		{ "device",		DEVICE },
 		{ "disable",		DISABLE },
@@ -793,6 +838,7 @@ lookup(char *s)
 		{ "net",		NET },
 		{ "owner",		OWNER },
 		{ "parallel",		PARALLEL },
+		{ "path",		PATH },
 		{ "prefix",		PREFIX },
 		{ "rdomain",		RDOMAIN },
 		{ "size",		SIZE },
@@ -1149,6 +1195,10 @@ parse_config(const char *filename)
 	/* Set the default switch type */
 	(void)strlcpy(vsw_type, VMD_SWITCH_TYPE, sizeof(vsw_type));
 
+	env->vmd_cfg.cfg_agentx.ax_enabled = 0;
+	env->vmd_cfg.cfg_agentx.ax_context[0] = '\0';
+	env->vmd_cfg.cfg_agentx.ax_path[0] = '\0';
+
 	yyparse();
 	errors = file->errors;
 	popfile();
diff --git a/usr.sbin/vmd/proc.h b/usr.sbin/vmd/proc.h
index dba9972dd41..123df4fe465 100644
--- a/usr.sbin/vmd/proc.h
+++ b/usr.sbin/vmd/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.20 2021/06/16 16:55:02 dv Exp $	*/
+/*	$OpenBSD: proc.h,v 1.21 2022/09/13 10:28:19 martijn Exp $	*/
 
 /*
  * Copyright (c) 2010-2015 Reyk Floeter <reyk@openbsd.org>
@@ -79,6 +79,7 @@ TAILQ_HEAD(ctl_connlist, ctl_conn);
 enum privsep_procid {
 	PROC_PARENT	= 0,
 	PROC_CONTROL,
+	PROC_AGENTX,
 	PROC_VMM,
 	PROC_PRIV,
 	PROC_MAX,
diff --git a/usr.sbin/vmd/vm.conf.5 b/usr.sbin/vmd/vm.conf.5
index d63a3890ed2..ca39b14c477 100644
--- a/usr.sbin/vmd/vm.conf.5
+++ b/usr.sbin/vmd/vm.conf.5
@@ -1,4 +1,4 @@
-.\" $OpenBSD: vm.conf.5,v 1.58 2022/08/04 11:50:51 stsp Exp $
+.\" $OpenBSD: vm.conf.5,v 1.59 2022/09/13 10:28:19 martijn Exp $
 .\"
 .\" Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org>
 .\" Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: August 4 2022 $
+.Dd $Mdocdate: September 13 2022 $
 .Dt VM.CONF 5
 .Os
 .Sh NAME
@@ -91,6 +91,19 @@ vm "vm1.example.com" {
 .Sh GLOBAL CONFIGURATION
 The following setting can be configured globally:
 .Bl -tag -width Ds
+.It Ic agentx Oo Ic context Ar context Oc Oo Ic path Ar path Oc
+Export vm metrics via an AgentX compatible
+.Pq snmp
+daemon by connecting to
+.Ar path .
+Metrics can be found under the vmMIB subtree
+.Pq mib-2.236 .
+If
+.Ar path
+is omitted it will default to
+.Pa /var/agentx/master .
+.Ar Context
+is the SNMPv3 context and can usually be omitted.
 .It Ic local prefix Ar address Ns Li / Ns Ar prefix
 Set the network prefix that is used to allocate subnets for
 local interfaces, see
diff --git a/usr.sbin/vmd/vm_agentx.c b/usr.sbin/vmd/vm_agentx.c
new file mode 100644
index 00000000000..e54133f325a
--- /dev/null
+++ b/usr.sbin/vmd/vm_agentx.c
@@ -0,0 +1,538 @@
+/*	$OpenBSD: vm_agentx.c,v 1.1 2022/09/13 10:28:19 martijn Exp $ */
+
+/*
+ * Copyright (c) 2022 Martijn van Duren <martijn@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <sys/un.h>
+
+#include <agentx.h>
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "proc.h"
+#include "vmd.h"
+
+struct conn {
+	struct event ev;
+	struct agentx *agentx;
+};
+
+void vm_agentx_run(struct privsep *, struct privsep_proc *, void *);
+int vm_agentx_dispatch_parent(int, struct privsep_proc *, struct imsg *);
+void vm_agentx_configure(struct vmd_agentx *);
+static void vm_agentx_nofd(struct agentx *, void *, int);
+static void vm_agentx_tryconnect(int, short, void *);
+static void vm_agentx_read(int, short, void *);
+static void vm_agentx_flush_pending(void);
+static int vm_agentx_sortvir(const void *, const void *);
+static int vm_agentx_adminstate(int);
+static int vm_agentx_operstate(int);
+static void vm_agentx_vmHvSoftware(struct agentx_varbind *);
+static void vm_agentx_vmHvVersion(struct agentx_varbind *);
+static void vm_agentx_vmHvObjectID(struct agentx_varbind *);
+static void vm_agentx_vminfo(struct agentx_varbind *);
+
+static struct agentx_index *vmIndex;
+static struct agentx_object *vmNumber, *vmName, *vmUUID, *vmOSType;
+static struct agentx_object *vmAdminState, *vmOperState, *vmAutoStart;
+static struct agentx_object *vmPersistent, *vmCurCpuNumber, *vmMinCpuNumber;
+static struct agentx_object *vmMaxCpuNumber, *vmMemUnit, *vmCurMem, *vmMinMem;
+static struct agentx_object *vmMaxMem;
+
+static struct vmd_agentx *vmd_agentx;
+
+static struct agentx_varbind **vminfo = NULL;
+static size_t vminfolen = 0;
+static size_t vminfosize = 0;
+static int vmcollecting = 0;
+
+#define VMMIB AGENTX_MIB2, 236
+#define VMOBJECTS VMMIB, 1
+#define VMHVSOFTWARE VMOBJECTS, 1, 1
+#define VMHVVERSION VMOBJECTS, 1, 2
+#define VMHVOBJECTID VMOBJECTS, 1, 3
+#define VMNUMBER VMOBJECTS, 2
+#define VMENTRY VMOBJECTS, 4, 1
+#define VMINDEX VMENTRY, 1
+#define VMNAME VMENTRY, 2
+#define VMUUID VMENTRY, 3
+#define VMOSTYPE VMENTRY, 4
+#define VMADMINSTATE VMENTRY, 5
+#define VMOPERSTATE VMENTRY, 6
+#define VMAUTOSTART VMENTRY, 7
+#define VMPERSISTENT VMENTRY, 8
+#define VMCURCPUNUMBER VMENTRY, 9
+#define VMMINCPUNUMBER VMENTRY, 10
+#define VMMAXCPUNUMBER VMENTRY, 11
+#define VMMEMUNIT VMENTRY, 12
+#define VMCURMEM VMENTRY, 13
+#define VMMINMEM VMENTRY, 14
+#define VMMAXMEM VMENTRY, 15
+
+#define AGENTX_GROUP "_agentx"
+#define MEM_SCALE (1024 * 1024)
+
+static struct privsep_proc procs[] = {
+	{ "parent",	PROC_PARENT,	vm_agentx_dispatch_parent  },
+};
+
+void
+vm_agentx(struct privsep *ps, struct privsep_proc *p)
+{
+	struct group *grp;
+
+	/*
+	 * Make sure we can connect to /var/agentx/master with the correct
+	 * group permissions.
+	 */
+	if ((grp = getgrnam(AGENTX_GROUP)) == NULL)
+		fatal("getgrnam");
+	ps->ps_pw->pw_gid = grp->gr_gid;
+
+	proc_run(ps, p, procs, nitems(procs), vm_agentx_run, NULL);
+}
+
+void
+vm_agentx_shutdown(void)
+{
+}
+
+void
+vm_agentx_run(struct privsep *ps, struct privsep_proc *p, void *arg)
+{
+	/*
+	 * pledge in agentx process
+	 * stdio - for malloc and basic I/O including events.
+	 * recvfd - for the proc fd exchange.
+	 * unix - for access to the agentx master socket.
+	 */
+	if (pledge("stdio recvfd unix", NULL) == -1)
+		fatal("pledge");
+}
+
+int
+vm_agentx_dispatch_parent(int fd, struct privsep_proc *p, struct imsg *imsg)
+{
+	static struct vmop_info_result *vir = NULL;
+	static struct vmop_info_result *mvir = NULL;
+	struct vmd *env = p->p_ps->ps_env; 
+	struct vmop_info_result *tvir;
+	struct agentx_object *reqObject;
+	static size_t nvir = 0;
+	static size_t virlen = 0;
+	static int error = 0;
+	size_t i, j, index;
+	enum agentx_request_type rtype;
+
+	switch (imsg->hdr.type) {
+	case IMSG_VMDOP_GET_INFO_VM_DATA:
+		if (error)
+			break;
+		if (nvir + 1 > virlen) {
+			tvir = reallocarray(vir, virlen + 10, sizeof(*vir));
+			if (tvir == NULL) {
+				log_warn("%s: Couldn't dispatch vm information",
+				    __func__);
+				error = 1;
+				break;
+			}
+			virlen += 10;
+			vir = tvir;
+		}
+                memcpy(&(vir[nvir++]), imsg->data, sizeof(vir[nvir]));
+		break;
+	case IMSG_VMDOP_GET_INFO_VM_END_DATA:
+		vmcollecting = 0;
+		if (error) {
+			for (i = 0; i < vminfolen; i++)
+				agentx_varbind_error(vminfo[i]);
+			vminfolen = 0;
+			error = 0;
+			nvir = 0;
+			return (0);
+		}
+
+		qsort(vir, nvir, sizeof(*vir), vm_agentx_sortvir);
+		for (i = 0; i < vminfolen; i++) {
+			reqObject = agentx_varbind_get_object(vminfo[i]);
+			if (reqObject == vmNumber) {
+				agentx_varbind_integer(vminfo[i],
+				    (int32_t)nvir);
+				continue;
+			}
+			index = agentx_varbind_get_index_integer(vminfo[i],
+			    vmIndex);
+			rtype = agentx_varbind_request(vminfo[i]);
+			for (j = 0; j < nvir; j++) {
+				if (vir[j].vir_info.vir_id < index)
+					continue;
+				if (vir[j].vir_info.vir_id == index &&
+				    (rtype == AGENTX_REQUEST_TYPE_GET ||
+				    rtype ==
+				    AGENTX_REQUEST_TYPE_GETNEXTINCLUSIVE))
+					break;
+				if (vir[j].vir_info.vir_id > index &&
+				    (rtype == AGENTX_REQUEST_TYPE_GETNEXT ||
+				    rtype ==
+				    AGENTX_REQUEST_TYPE_GETNEXTINCLUSIVE))
+					break;
+			}
+			if (j == nvir) {
+				agentx_varbind_notfound(vminfo[i]);
+				continue;
+			}
+			mvir = &(vir[j]);
+			agentx_varbind_set_index_integer(vminfo[i], vmIndex,
+			    mvir->vir_info.vir_id);
+			if (reqObject == vmName)
+				agentx_varbind_string(vminfo[i],
+				    mvir->vir_info.vir_name);
+			else if (reqObject == vmUUID)
+				agentx_varbind_string(vminfo[i], "");
+			else if (reqObject == vmOSType)
+				agentx_varbind_string(vminfo[i], "");
+			else if (reqObject == vmAdminState)
+				agentx_varbind_integer(vminfo[i],
+				    vm_agentx_adminstate(mvir->vir_state));
+			else if (reqObject == vmOperState)
+				agentx_varbind_integer(vminfo[i],
+				    vm_agentx_operstate(mvir->vir_state));
+			else if (reqObject == vmAutoStart)
+				agentx_varbind_integer(vminfo[i],
+				    mvir->vir_state & VM_STATE_DISABLED ?
+				    3 : 2);
+/* XXX We can dynamically create vm's but I don't know how to differentiate */
+			else if (reqObject == vmPersistent)
+				agentx_varbind_integer(vminfo[i], 1);
+/* We currently only support a single CPU */
+			else if (reqObject == vmCurCpuNumber ||
+			    reqObject == vmMinCpuNumber ||
+			    reqObject == vmMaxCpuNumber)
+				agentx_varbind_integer(vminfo[i],
+				    mvir->vir_info.vir_ncpus);
+			else if (reqObject == vmMemUnit)
+				agentx_varbind_integer(vminfo[i], MEM_SCALE);
+			else if (reqObject == vmCurMem)
+				agentx_varbind_integer(vminfo[i],
+				    mvir->vir_info.vir_used_size / MEM_SCALE);
+			else if (reqObject == vmMinMem)
+				agentx_varbind_integer(vminfo[i], -1);
+			else if (reqObject == vmMaxMem)
+				agentx_varbind_integer(vminfo[i],
+				    mvir->vir_info.vir_memory_size / MEM_SCALE);
+/* We probably had a reload */
+			else
+				agentx_varbind_notfound(vminfo[i]);
+		}
+		vminfolen = 0;
+		nvir = 0;
+		break;
+	case IMSG_VMDOP_CONFIG:
+		config_getconfig(env, imsg);
+		vm_agentx_configure(&env->vmd_cfg.cfg_agentx);
+		break;
+	default:
+		return (-1);
+	}
+	return (0);
+}
+
+void
+vm_agentx_configure(struct vmd_agentx *env)
+{
+	static char curpath[sizeof(env->ax_path)];
+	static char curcontext[sizeof(env->ax_context)];
+	static struct conn *conn;
+	static struct agentx_session *sess;
+	static struct agentx_context *ctx;
+	struct agentx_region *vmMIB;
+	char *context = env->ax_context[0] == '\0' ? NULL : env->ax_context;
+	int changed = 0;
+
+	vmd_agentx = env;
+
+	agentx_log_fatal = fatalx;
+	agentx_log_warn = log_warnx;
+	agentx_log_info = log_info;
+	agentx_log_debug = log_debug;
+
+	if (!vmd_agentx->ax_enabled) {
+		if (conn != NULL) {
+			agentx_free(conn->agentx);
+			conn = NULL;
+			sess = NULL;
+			ctx = NULL;
+			vm_agentx_flush_pending();
+		}
+		return;
+	}
+
+	if (strcmp(curpath, vmd_agentx->ax_path) != 0 || conn == NULL) {
+		if (conn != NULL) {
+			agentx_free(conn->agentx);
+			conn = NULL;
+			sess = NULL;
+			ctx = NULL;
+			vm_agentx_flush_pending();
+		}
+
+		if ((conn = malloc(sizeof(*conn))) == NULL)
+			fatal(NULL);
+		/* Set to something so we can safely event_del */
+		evtimer_set(&conn->ev, vm_agentx_tryconnect, conn);
+		/* result assigned in vm_agentx_nofd */
+		if (agentx(vm_agentx_nofd, conn) == NULL)
+			fatal("Can't setup agentx");
+		sess = agentx_session(conn->agentx, NULL, 0, "vmd", 0);
+		if (sess == NULL)
+			fatal("Can't setup agentx session");
+		(void) strlcpy(curpath, vmd_agentx->ax_path, sizeof(curpath));
+		changed = 1;
+	}
+
+	if (strcmp(curcontext, vmd_agentx->ax_context) != 0 || changed) {
+		if (!changed) {
+			agentx_context_free(ctx);
+			vm_agentx_flush_pending();
+		}
+		if ((ctx = agentx_context(sess, context)) == NULL)
+			fatal("Can't setup agentx context");
+		strlcpy(curcontext, vmd_agentx->ax_context, sizeof(curcontext));
+		changed = 1;
+	}
+
+	if (!changed)
+		return;
+
+	if ((vmMIB = agentx_region(ctx, AGENTX_OID(VMMIB), 1)) == NULL)
+		fatal("agentx_region vmMIB");
+	
+	if ((vmIndex = agentx_index_integer_dynamic(vmMIB,
+	    AGENTX_OID(VMINDEX))) == NULL)
+		fatal("agentx_index_integer_dynamic");
+        if ((agentx_object(vmMIB, AGENTX_OID(VMHVSOFTWARE), NULL, 0, 0,
+	    vm_agentx_vmHvSoftware)) == NULL ||
+            (agentx_object(vmMIB, AGENTX_OID(VMHVVERSION), NULL, 0, 0,
+	    vm_agentx_vmHvVersion)) == NULL ||
+            (agentx_object(vmMIB, AGENTX_OID(VMHVOBJECTID), NULL, 0, 0,
+	    vm_agentx_vmHvObjectID)) == NULL ||
+            (vmNumber = agentx_object(vmMIB, AGENTX_OID(VMNUMBER), NULL, 0, 0,
+	    vm_agentx_vminfo)) == NULL ||
+            (vmName = agentx_object(vmMIB, AGENTX_OID(VMNAME), &vmIndex, 1, 0,
+	    vm_agentx_vminfo)) == NULL ||
+            (vmUUID = agentx_object(vmMIB, AGENTX_OID(VMUUID), &vmIndex, 1, 0,
+	    vm_agentx_vminfo)) == NULL ||
+            (vmOSType = agentx_object(vmMIB, AGENTX_OID(VMOSTYPE), &vmIndex, 1,
+	    0, vm_agentx_vminfo)) == NULL ||
+            (vmAdminState = agentx_object(vmMIB, AGENTX_OID(VMADMINSTATE),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmOperState = agentx_object(vmMIB, AGENTX_OID(VMOPERSTATE),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmAutoStart = agentx_object(vmMIB, AGENTX_OID(VMAUTOSTART),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmPersistent = agentx_object(vmMIB, AGENTX_OID(VMPERSISTENT),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmCurCpuNumber = agentx_object(vmMIB, AGENTX_OID(VMCURCPUNUMBER),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmMinCpuNumber = agentx_object(vmMIB, AGENTX_OID(VMMINCPUNUMBER),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmMaxCpuNumber = agentx_object(vmMIB, AGENTX_OID(VMMAXCPUNUMBER),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmMemUnit = agentx_object(vmMIB, AGENTX_OID(VMMEMUNIT),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmCurMem = agentx_object(vmMIB, AGENTX_OID(VMCURMEM),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmMinMem = agentx_object(vmMIB, AGENTX_OID(VMMINMEM),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL ||
+            (vmMaxMem = agentx_object(vmMIB, AGENTX_OID(VMMAXMEM),
+	    &vmIndex, 1, 0, vm_agentx_vminfo)) == NULL)
+                fatal("agentx_object_ro");
+}
+
+static void
+vm_agentx_nofd(struct agentx *agentx, void *cookie, int close)
+{
+	struct conn *conn = cookie;
+
+	conn->agentx = agentx;
+	event_del(&conn->ev);
+	if (close)
+		free(conn);
+	else
+		vm_agentx_tryconnect(-1, 0, conn);
+}
+
+static void
+vm_agentx_tryconnect(int fd, short event, void *cookie)
+{
+	struct sockaddr_un sun;
+	struct timeval timeout = {3, 0};
+	struct conn *conn = cookie;
+
+	sun.sun_len = sizeof(sun);
+	sun.sun_family = AF_UNIX;
+	strlcpy(sun.sun_path, vmd_agentx->ax_path, sizeof(sun.sun_path));
+	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
+		log_warn("socket");
+		goto fail;
+	} else if (connect(fd, (struct sockaddr *)&sun, sun.sun_len) == -1) {
+		log_warn("connect");
+		close(fd);
+		goto fail;
+	}
+	agentx_connect(conn->agentx, fd);
+
+	event_set(&conn->ev, fd, EV_READ|EV_PERSIST, vm_agentx_read, conn);
+	event_add(&conn->ev, NULL);
+
+	return;
+fail:
+	evtimer_set(&conn->ev, vm_agentx_tryconnect, conn);
+	evtimer_add(&conn->ev, &timeout);
+}
+
+static void
+vm_agentx_read(int fd, short event, void *cookie)
+{
+	struct conn *conn = cookie;
+
+	agentx_read(conn->agentx);
+}
+
+static void
+vm_agentx_flush_pending(void)
+{
+	size_t i;
+
+	for (i = 0; i < vminfolen; i++)
+		agentx_varbind_notfound(vminfo[i]);
+	vminfolen = 0;
+}
+
+static int
+vm_agentx_sortvir(const void *c1, const void *c2)
+{
+	const struct vmop_info_result *v1 = c1, *v2 = c2;
+
+	return (v1->vir_info.vir_id < v2->vir_info.vir_id ? -1 :
+	    v1->vir_info.vir_id > v2->vir_info.vir_id);
+}
+
+static int
+vm_agentx_adminstate(int mask)
+{
+	if (mask & VM_STATE_PAUSED)
+                return (3);
+        else if (mask & VM_STATE_RUNNING)
+                return (1);
+        else if (mask & VM_STATE_SHUTDOWN)
+                return (4);
+        /* Presence of absence of other flags */
+        else if (!mask || (mask & VM_STATE_DISABLED))
+                return (4);
+
+        return 4;
+}
+
+static int
+vm_agentx_operstate(int mask)
+{
+	if (mask & VM_STATE_PAUSED)
+                return (8);
+        else if (mask & VM_STATE_RUNNING)
+                return (4);
+        else if (mask & VM_STATE_SHUTDOWN)
+                return (11);
+        /* Presence of absence of other flags */
+        else if (!mask || (mask & VM_STATE_DISABLED))
+                return (11);
+
+        return (11);
+}
+
+static void
+vm_agentx_vmHvSoftware(struct agentx_varbind *vb)
+{
+	agentx_varbind_string(vb, "OpenBSD VMM");
+}
+
+static void
+vm_agentx_vmHvVersion(struct agentx_varbind *vb)
+{
+	int osversid[] = {CTL_KERN, KERN_OSRELEASE};
+	static char osvers[10] = "";
+	size_t osverslen;
+
+	if (osvers[0] == '\0') {
+		osverslen = sizeof(osvers);
+		if (sysctl(osversid, 2, osvers, &osverslen, NULL,
+		    0) == -1) {
+			log_warn("Failed vmHvVersion sysctl");
+			agentx_varbind_string(vb, "unknown");
+			return;
+		}
+		if (osverslen >= sizeof(osvers))
+			osverslen = sizeof(osvers) - 1;
+		osvers[osverslen] = '\0';
+	}
+	agentx_varbind_string(vb, osvers);
+}
+
+static void
+vm_agentx_vmHvObjectID(struct agentx_varbind *vb)
+{
+	agentx_varbind_oid(vb, AGENTX_OID(0, 0));
+}
+
+static void
+vm_agentx_vminfo(struct agentx_varbind *vb)
+{
+	extern struct vmd *env;
+	struct agentx_varbind **tvminfo;
+
+	if (vminfolen >= vminfosize) {
+		if ((tvminfo = reallocarray(vminfo, vminfosize + 10,
+		    sizeof(*vminfo))) == NULL) {
+			log_warn("%s: Couldn't retrieve vm information",
+			    __func__);
+			agentx_varbind_error(vb);
+			return;
+		}
+		vminfo = tvminfo;
+		vminfosize += 10;
+	}
+
+	if (!vmcollecting) {
+		if (proc_compose_imsg(&(env->vmd_ps), PROC_PARENT, -1,
+		    IMSG_VMDOP_GET_INFO_VM_REQUEST, IMSG_AGENTX_PEERID,
+		    -1, NULL, 0) == -1) {
+			log_warn("%s: Couldn't retrieve vm information",
+			    __func__);
+			agentx_varbind_error(vb);
+			return;
+		}
+		vmcollecting = 1;
+	}
+
+	vminfo[vminfolen++] = vb;
+}
diff --git a/usr.sbin/vmd/vmd.c b/usr.sbin/vmd/vmd.c
index 74b4a3ffe8e..2f3ac1a76f2 100644
--- a/usr.sbin/vmd/vmd.c
+++ b/usr.sbin/vmd/vmd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmd.c,v 1.131 2022/05/08 14:44:54 dv Exp $	*/
+/*	$OpenBSD: vmd.c,v 1.132 2022/09/13 10:28:19 martijn Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -57,6 +57,7 @@ void	 vmd_shutdown(void);
 int	 vmd_control_run(void);
 int	 vmd_dispatch_control(int, struct privsep_proc *, struct imsg *);
 int	 vmd_dispatch_vmm(int, struct privsep_proc *, struct imsg *);
+int	 vmd_dispatch_agentx(int, struct privsep_proc *, struct imsg *);
 int	 vmd_dispatch_priv(int, struct privsep_proc *, struct imsg *);
 int	 vmd_check_vmh(struct vm_dump_header *);
 
@@ -73,6 +74,7 @@ static struct privsep_proc procs[] = {
 	{ "priv",	PROC_PRIV,	vmd_dispatch_priv, priv },
 	{ "control",	PROC_CONTROL,	vmd_dispatch_control, control },
 	{ "vmm",	PROC_VMM,	vmd_dispatch_vmm, vmm, vmm_shutdown },
+	{ "agentx", 	PROC_AGENTX,	vmd_dispatch_agentx, vm_agentx, vm_agentx_shutdown, "/" }
 };
 
 enum privsep_procid privsep_process;
@@ -501,7 +503,9 @@ vmd_dispatch_vmm(int fd, struct privsep_proc *p, struct imsg *imsg)
 			vir.vir_uid = vm->vm_uid;
 			vir.vir_gid = vm->vm_params.vmc_owner.gid;
 		}
-		if (proc_compose_imsg(ps, PROC_CONTROL, -1, imsg->hdr.type,
+		if (proc_compose_imsg(ps,
+		    imsg->hdr.peerid == IMSG_AGENTX_PEERID ?
+		    PROC_AGENTX : PROC_CONTROL, -1, imsg->hdr.type,
 		    imsg->hdr.peerid, -1, &vir, sizeof(vir)) == -1) {
 			log_debug("%s: GET_INFO_VM failed for vm %d, removing",
 			    __func__, vm->vm_vmid);
@@ -533,7 +537,9 @@ vmd_dispatch_vmm(int fd, struct privsep_proc *p, struct imsg *imsg)
 				log_debug("%s: vm: %d, vm_state: 0x%x",
 				    __func__, vm->vm_vmid, vm->vm_state);
 				vir.vir_state = vm->vm_state;
-				if (proc_compose_imsg(ps, PROC_CONTROL, -1,
+				if (proc_compose_imsg(ps,
+				    imsg->hdr.peerid == IMSG_AGENTX_PEERID ?
+				    PROC_AGENTX : PROC_CONTROL, -1,
 				    IMSG_VMDOP_GET_INFO_VM_DATA,
 				    imsg->hdr.peerid, -1, &vir,
 				    sizeof(vir)) == -1) {
@@ -545,7 +551,9 @@ vmd_dispatch_vmm(int fd, struct privsep_proc *p, struct imsg *imsg)
 			}
 		}
 		IMSG_SIZE_CHECK(imsg, &res);
-		proc_forward_imsg(ps, imsg, PROC_CONTROL, -1);
+		proc_forward_imsg(ps, imsg,
+		    imsg->hdr.peerid == IMSG_AGENTX_PEERID ?
+		    PROC_AGENTX : PROC_CONTROL, -1);
 		break;
 	default:
 		return (-1);
@@ -555,6 +563,21 @@ vmd_dispatch_vmm(int fd, struct privsep_proc *p, struct imsg *imsg)
 }
 
 int
+vmd_dispatch_agentx(int fd, struct privsep_proc *p, struct imsg *imsg)
+{
+	struct privsep			*ps = p->p_ps;
+
+	switch (imsg->hdr.type) {
+	case IMSG_VMDOP_GET_INFO_VM_REQUEST:
+		proc_forward_imsg(ps, imsg, PROC_VMM, -1);
+		return (0);
+	default:
+		break;
+	}
+	return (-1);
+}
+
+int
 vmd_dispatch_priv(int fd, struct privsep_proc *p, struct imsg *imsg)
 {
 	struct vmop_addr_result	 var;
@@ -1236,24 +1259,24 @@ vm_claimid(const char *name, int uid, uint32_t *id)
 
 	if (++env->vmd_nvm == 0) {
 		log_warnx("too many vms");
-		return -1;
+		return (-1);
 	}
 	if ((n2i = calloc(1, sizeof(struct name2id))) == NULL) {
 		log_warnx("could not alloc vm name");
-		return -1;
+		return (-1);
 	}
 	n2i->id = env->vmd_nvm;
 	n2i->uid = uid;
 	if (strlcpy(n2i->name, name, sizeof(n2i->name)) >= sizeof(n2i->name)) {
 		log_warnx("vm name too long");
 		free(n2i);
-		return -1;
+		return (-1);
 	}
 	TAILQ_INSERT_TAIL(env->vmd_known, n2i, entry);
 
 out:
 	*id = n2i->id;
-	return 0;
+	return (0);
 }
 
 int
diff --git a/usr.sbin/vmd/vmd.h b/usr.sbin/vmd/vmd.h
index 31bc642afdb..9010ad6eb9f 100644
--- a/usr.sbin/vmd/vmd.h
+++ b/usr.sbin/vmd/vmd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmd.h,v 1.109 2022/05/03 21:39:18 dv Exp $	*/
+/*	$OpenBSD: vmd.h,v 1.110 2022/09/13 10:28:19 martijn Exp $	*/
 
 /*
  * Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org>
@@ -18,6 +18,7 @@
 
 #include <sys/types.h>
 #include <sys/queue.h>
+#include <sys/un.h>
 #include <sys/socket.h>
 
 #include <machine/vmmvar.h>
@@ -78,6 +79,8 @@
 #define VMD_CDROM_INVALID	1006
 #define VMD_PARENT_INVALID	1007
 
+#define IMSG_AGENTX_PEERID	(uint32_t)-2
+
 /* Image file signatures */
 #define VM_MAGIC_QCOW		"QFI\xfb"
 
@@ -330,6 +333,17 @@ struct address {
 };
 TAILQ_HEAD(addresslist, address);
 
+#define SUN_PATH_LEN		(sizeof(((struct sockaddr_un *)NULL)->sun_path))
+struct vmd_agentx {
+	int			 ax_enabled;
+	char			 ax_path[SUN_PATH_LEN];
+	/*
+	 * SNMP-VIEW-BASED-ACM-MIB:vacmContextName
+	 * Should probably be a define in agentx.h
+	 */
+	char			 ax_context[32 + 1];
+};
+
 struct vmd_config {
 	unsigned int		 cfg_flags;
 #define VMD_CFG_INET6		0x01
@@ -340,6 +354,7 @@ struct vmd_config {
 	int			 parallelism;
 	struct address		 cfg_localprefix;
 	struct address		 cfg_localprefix6;
+	struct vmd_agentx	 cfg_agentx;
 };
 
 struct vmd {
@@ -481,6 +496,10 @@ int	 config_getdisk(struct privsep *, struct imsg *);
 int	 config_getif(struct privsep *, struct imsg *);
 int	 config_getcdrom(struct privsep *, struct imsg *);
 
+/* vm_agentx.c */
+void vm_agentx(struct privsep *, struct privsep_proc *);
+void vm_agentx_shutdown(void);
+
 /* parse.y */
 int	 parse_config(const char *);
 int	 cmdline_symset(char *);