diff mbox series

[v2,7/7] tools/xenstored: use new stable interface instead of libxenctrl

Message ID 20241206130221.17773-8-jgross@suse.com (mailing list archive)
State Superseded
Headers show
Series remove libxenctrl usage from xenstored | expand

Commit Message

Jürgen Groß Dec. 6, 2024, 1:02 p.m. UTC 
Replace the current use of the unstable xc_domain_getinfo_single()
interface with the stable domctl XEN_DOMCTL_get_domain_state call
via the new libxenmanage library.

This will remove the last usage of libxenctrl by Xenstore, so update
the library dependencies accordingly.

For now only do a direct replacement without using the functionality
of obtaining information about domains having changed the state.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V1:
- use library instead of direct hypercall, only replace current
  libxenctrl use case

Please note that this patch can be committed only after the related
Mini-OS patch "config: add support for libxenmanage" has gone in AND
the Mini-OS commit-id has been updated in Config.mk accordingly!

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 stubdom/Makefile                |  8 ++---
 stubdom/mini-os.mk              |  1 +
 tools/xenstored/Makefile        |  2 +-
 tools/xenstored/Makefile.common |  2 +-
 tools/xenstored/core.h          |  1 -
 tools/xenstored/domain.c        | 52 ++++++++++++---------------------
 tools/xenstored/lu.c            |  1 +
 tools/xenstored/lu_daemon.c     |  1 +
 8 files changed, 28 insertions(+), 40 deletions(-)

Comments

Samuel Thibault Dec. 8, 2024, 8:38 p.m. UTC | #1 
Juergen Gross, le ven. 06 déc. 2024 14:02:21 +0100, a ecrit:
> Replace the current use of the unstable xc_domain_getinfo_single()
> interface with the stable domctl XEN_DOMCTL_get_domain_state call
> via the new libxenmanage library.
> 
> This will remove the last usage of libxenctrl by Xenstore, so update
> the library dependencies accordingly.
> 
> For now only do a direct replacement without using the functionality
> of obtaining information about domains having changed the state.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

> ---
> V1:
> - use library instead of direct hypercall, only replace current
>   libxenctrl use case
> 
> Please note that this patch can be committed only after the related
> Mini-OS patch "config: add support for libxenmanage" has gone in AND
> the Mini-OS commit-id has been updated in Config.mk accordingly!
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
>  stubdom/Makefile                |  8 ++---
>  stubdom/mini-os.mk              |  1 +
>  tools/xenstored/Makefile        |  2 +-
>  tools/xenstored/Makefile.common |  2 +-
>  tools/xenstored/core.h          |  1 -
>  tools/xenstored/domain.c        | 52 ++++++++++++---------------------
>  tools/xenstored/lu.c            |  1 +
>  tools/xenstored/lu_daemon.c     |  1 +
>  8 files changed, 28 insertions(+), 40 deletions(-)
> 
> diff --git a/stubdom/Makefile b/stubdom/Makefile
> index 2a81af28a1..ca800b243c 100644
> --- a/stubdom/Makefile
> +++ b/stubdom/Makefile
> @@ -307,7 +307,7 @@ endif
>  # libraries under tools/libs
>  #######
>  
> -STUB_LIBS := toolcore toollog evtchn gnttab call foreignmemory devicemodel ctrl guest
> +STUB_LIBS := toolcore toollog evtchn gnttab call foreignmemory devicemodel ctrl guest manage
>  
>  LIBDEP_guest := cross-zlib
>  
> @@ -465,7 +465,7 @@ grub: cross-polarssl grub-upstream $(CROSS_ROOT) grub-$(XEN_TARGET_ARCH)-minios-
>  # xenstore
>  ##########
>  
> -xenstore-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog ctrl
> +xenstore-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog manage
>  xenstore-minios.gen.cfg: xenstore-minios.cfg Makefile
>  	$(GEN_config) >$@
>  
> @@ -480,7 +480,7 @@ xenstore: $(CROSS_ROOT) xenstore-minios-config.mk
>  # xenstorepvh
>  #############
>  
> -xenstorepvh-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog ctrl
> +xenstorepvh-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog manage
>  xenstorepvh-minios.gen.cfg: xenstorepvh-minios.cfg Makefile
>  	$(GEN_config) >$@
>  
> @@ -523,7 +523,7 @@ else
>  pv-grub-if-enabled:
>  endif
>  
> -XENSTORE_DEPS := libxenevtchn libxengnttab libxenctrl
> +XENSTORE_DEPS := libxenevtchn libxengnttab libxenmanage
>  
>  .PHONY: xenstore-stubdom
>  xenstore-stubdom: mini-os-$(XEN_TARGET_ARCH)-xenstore $(XENSTORE_DEPS) xenstore
> diff --git a/stubdom/mini-os.mk b/stubdom/mini-os.mk
> index 7e4968e026..be32302f9e 100644
> --- a/stubdom/mini-os.mk
> +++ b/stubdom/mini-os.mk
> @@ -13,5 +13,6 @@ GNTTAB_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/gnttab
>  CALL_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/call
>  FOREIGNMEMORY_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/foreignmemory
>  DEVICEMODEL_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/devicemodel
> +MANAGE_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/manage
>  CTRL_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/ctrl
>  GUEST_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/guest
> diff --git a/tools/xenstored/Makefile b/tools/xenstored/Makefile
> index 09adfe1d50..81c42838e0 100644
> --- a/tools/xenstored/Makefile
> +++ b/tools/xenstored/Makefile
> @@ -5,7 +5,7 @@ include Makefile.common
>  
>  xenstored: LDLIBS += $(LDLIBS_libxenevtchn)
>  xenstored: LDLIBS += $(LDLIBS_libxengnttab)
> -xenstored: LDLIBS += $(LDLIBS_libxenctrl)
> +xenstored: LDLIBS += $(LDLIBS_libxenmanage)
>  xenstored: LDLIBS += -lrt
>  xenstored: LDLIBS += $(SOCKET_LIBS)
>  
> diff --git a/tools/xenstored/Makefile.common b/tools/xenstored/Makefile.common
> index 27fdb3b49e..271134fcc1 100644
> --- a/tools/xenstored/Makefile.common
> +++ b/tools/xenstored/Makefile.common
> @@ -12,7 +12,7 @@ XENSTORED_OBJS-$(CONFIG_MiniOS) += minios.o lu_minios.o
>  # Include configure output (config.h)
>  CFLAGS += -include $(XEN_ROOT)/tools/config.h
>  CFLAGS += $(CFLAGS_libxenevtchn)
> -CFLAGS += $(CFLAGS_libxenctrl)
> +CFLAGS += $(CFLAGS_libxenmanage)
>  CFLAGS += $(CFLAGS_libxentoolcore)
>  
>  $(XENSTORED_OBJS-y): CFLAGS += $(CFLAGS_libxengnttab)
> diff --git a/tools/xenstored/core.h b/tools/xenstored/core.h
> index e58779e88c..632886cecf 100644
> --- a/tools/xenstored/core.h
> +++ b/tools/xenstored/core.h
> @@ -19,7 +19,6 @@
>  #ifndef _XENSTORED_CORE_H
>  #define _XENSTORED_CORE_H
>  
> -#include <xenctrl.h>
>  #include <xengnttab.h>
>  
>  #include <sys/types.h>
> diff --git a/tools/xenstored/domain.c b/tools/xenstored/domain.c
> index 64c8fd0cc3..c0264d9477 100644
> --- a/tools/xenstored/domain.c
> +++ b/tools/xenstored/domain.c
> @@ -34,14 +34,15 @@
>  #include "control.h"
>  
>  #include <xenevtchn.h>
> -#include <xenctrl.h>
> +#include <xenmanage.h>
> +#include <xen-barrier.h>
>  #include <xen/grant_table.h>
>  
>  #ifdef __MINIOS__
>  #include <mini-os/xenbus.h>
>  #endif
>  
> -static xc_interface **xc_handle;
> +static xenmanage_handle *xm_handle;
>  xengnttab_handle **xgt_handle;
>  static evtchn_port_t virq_port;
>  
> @@ -619,32 +620,28 @@ static int destroy_domain(void *_domain)
>  	return 0;
>  }
>  
> -static bool get_domain_info(unsigned int domid, xc_domaininfo_t *dominfo)
> -{
> -	return xc_domain_getinfo_single(*xc_handle, domid, dominfo) == 0;
> -}
> -
>  static int check_domain(const void *k, void *v, void *arg)
>  {
> -	xc_domaininfo_t dominfo;
> +	unsigned int state;
>  	struct connection *conn;
> -	bool dom_valid;
> +	int dom_invalid;
>  	struct domain *domain = v;
>  	bool *notify = arg;
>  
> -	dom_valid = get_domain_info(domain->domid, &dominfo);
> +	dom_invalid = xenmanage_get_domain_info(xm_handle, domain->domid,
> +						&state, NULL);
>  	if (!domain->introduced) {
> -		if (!dom_valid)
> +		if (dom_invalid)
>  			talloc_free(domain);
>  		return 0;
>  	}
> -	if (dom_valid) {
> -		if ((dominfo.flags & XEN_DOMINF_shutdown)
> +	if (!dom_invalid) {
> +		if ((state & XENMANAGE_GETDOMSTATE_STATE_SHUTDOWN)
>  		    && !domain->shutdown) {
>  			domain->shutdown = true;
>  			*notify = true;
>  		}
> -		if (!(dominfo.flags & XEN_DOMINF_dying))
> +		if (!(state & XENMANAGE_GETDOMSTATE_STATE_DYING))
>  			return 0;
>  	}
>  	if (domain->conn) {
> @@ -786,10 +783,9 @@ static struct domain *find_or_alloc_domain(const void *ctx, unsigned int domid)
>  static struct domain *find_or_alloc_existing_domain(unsigned int domid)
>  {
>  	struct domain *domain;
> -	xc_domaininfo_t dominfo;
>  
>  	domain = find_domain_struct(domid);
> -	if (!domain && get_domain_info(domid, &dominfo))
> +	if (!domain && !xenmanage_get_domain_info(xm_handle, domid, NULL, NULL))
>  		domain = alloc_domain(NULL, domid);
>  
>  	return domain;
> @@ -1187,12 +1183,6 @@ int do_reset_watches(const void *ctx, struct connection *conn,
>  	return 0;
>  }
>  
> -static int close_xc_handle(void *_handle)
> -{
> -	xc_interface_close(*(xc_interface**)_handle);
> -	return 0;
> -}
> -
>  static int close_xgt_handle(void *_handle)
>  {
>  	xengnttab_close(*(xengnttab_handle **)_handle);
> @@ -1258,15 +1248,9 @@ void domain_early_init(void)
>  	if (!domhash)
>  		barf_perror("Failed to allocate domain hashtable");
>  
> -	xc_handle = talloc(talloc_autofree_context(), xc_interface*);
> -	if (!xc_handle)
> -		barf_perror("Failed to allocate domain handle");
> -
> -	*xc_handle = xc_interface_open(0,0,0);
> -	if (!*xc_handle)
> -		barf_perror("Failed to open connection to hypervisor");
> -
> -	talloc_set_destructor(xc_handle, close_xc_handle);
> +	xm_handle = xenmanage_open(NULL, 0);
> +	if (!xm_handle)
> +		barf_perror("Failed to open connection to libxenmanage");
>  
>  	xgt_handle = talloc(talloc_autofree_context(), xengnttab_handle*);
>  	if (!xgt_handle)
> @@ -1306,6 +1290,8 @@ void domain_deinit(void)
>  {
>  	if (virq_port)
>  		xenevtchn_unbind(xce_handle, virq_port);
> +
> +	xenmanage_close(xm_handle);
>  }
>  
>  /*
> @@ -1335,13 +1321,13 @@ int domain_alloc_permrefs(struct node_perms *perms)
>  {
>  	unsigned int i, domid;
>  	struct domain *d;
> -	xc_domaininfo_t dominfo;
>  
>  	for (i = 0; i < perms->num; i++) {
>  		domid = perms->p[i].id;
>  		d = find_domain_struct(domid);
>  		if (!d) {
> -			if (!get_domain_info(domid, &dominfo))
> +			if (xenmanage_get_domain_info(xm_handle, domid,
> +						      NULL, NULL))
>  				perms->p[i].perms |= XS_PERM_IGNORE;
>  			else if (!alloc_domain(NULL, domid))
>  				return ENOMEM;
> diff --git a/tools/xenstored/lu.c b/tools/xenstored/lu.c
> index bec2a84e10..4fccbbc195 100644
> --- a/tools/xenstored/lu.c
> +++ b/tools/xenstored/lu.c
> @@ -11,6 +11,7 @@
>  #include <stdlib.h>
>  #include <syslog.h>
>  #include <time.h>
> +#include <unistd.h>
>  #include <sys/mman.h>
>  #include <sys/stat.h>
>  
> diff --git a/tools/xenstored/lu_daemon.c b/tools/xenstored/lu_daemon.c
> index 6df6c80a2a..88d8d9e1b3 100644
> --- a/tools/xenstored/lu_daemon.c
> +++ b/tools/xenstored/lu_daemon.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <syslog.h>
> +#include <unistd.h>
>  #include <sys/stat.h>
>  
>  #include "talloc.h"
> -- 
> 2.43.0
>
diff mbox series

Patch

diff --git a/stubdom/Makefile b/stubdom/Makefile
index 2a81af28a1..ca800b243c 100644
--- a/stubdom/Makefile
+++ b/stubdom/Makefile
@@ -307,7 +307,7 @@  endif
 # libraries under tools/libs
 #######
 
-STUB_LIBS := toolcore toollog evtchn gnttab call foreignmemory devicemodel ctrl guest
+STUB_LIBS := toolcore toollog evtchn gnttab call foreignmemory devicemodel ctrl guest manage
 
 LIBDEP_guest := cross-zlib
 
@@ -465,7 +465,7 @@  grub: cross-polarssl grub-upstream $(CROSS_ROOT) grub-$(XEN_TARGET_ARCH)-minios-
 # xenstore
 ##########
 
-xenstore-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog ctrl
+xenstore-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog manage
 xenstore-minios.gen.cfg: xenstore-minios.cfg Makefile
 	$(GEN_config) >$@
 
@@ -480,7 +480,7 @@  xenstore: $(CROSS_ROOT) xenstore-minios-config.mk
 # xenstorepvh
 #############
 
-xenstorepvh-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog ctrl
+xenstorepvh-minios.gen.cfg: APP_LIBS = gnttab evtchn toollog manage
 xenstorepvh-minios.gen.cfg: xenstorepvh-minios.cfg Makefile
 	$(GEN_config) >$@
 
@@ -523,7 +523,7 @@  else
 pv-grub-if-enabled:
 endif
 
-XENSTORE_DEPS := libxenevtchn libxengnttab libxenctrl
+XENSTORE_DEPS := libxenevtchn libxengnttab libxenmanage
 
 .PHONY: xenstore-stubdom
 xenstore-stubdom: mini-os-$(XEN_TARGET_ARCH)-xenstore $(XENSTORE_DEPS) xenstore
diff --git a/stubdom/mini-os.mk b/stubdom/mini-os.mk
index 7e4968e026..be32302f9e 100644
--- a/stubdom/mini-os.mk
+++ b/stubdom/mini-os.mk
@@ -13,5 +13,6 @@  GNTTAB_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/gnttab
 CALL_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/call
 FOREIGNMEMORY_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/foreignmemory
 DEVICEMODEL_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/devicemodel
+MANAGE_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/manage
 CTRL_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/ctrl
 GUEST_PATH = $(XEN_ROOT)/stubdom/libs-$(MINIOS_TARGET_ARCH)/guest
diff --git a/tools/xenstored/Makefile b/tools/xenstored/Makefile
index 09adfe1d50..81c42838e0 100644
--- a/tools/xenstored/Makefile
+++ b/tools/xenstored/Makefile
@@ -5,7 +5,7 @@  include Makefile.common
 
 xenstored: LDLIBS += $(LDLIBS_libxenevtchn)
 xenstored: LDLIBS += $(LDLIBS_libxengnttab)
-xenstored: LDLIBS += $(LDLIBS_libxenctrl)
+xenstored: LDLIBS += $(LDLIBS_libxenmanage)
 xenstored: LDLIBS += -lrt
 xenstored: LDLIBS += $(SOCKET_LIBS)
 
diff --git a/tools/xenstored/Makefile.common b/tools/xenstored/Makefile.common
index 27fdb3b49e..271134fcc1 100644
--- a/tools/xenstored/Makefile.common
+++ b/tools/xenstored/Makefile.common
@@ -12,7 +12,7 @@  XENSTORED_OBJS-$(CONFIG_MiniOS) += minios.o lu_minios.o
 # Include configure output (config.h)
 CFLAGS += -include $(XEN_ROOT)/tools/config.h
 CFLAGS += $(CFLAGS_libxenevtchn)
-CFLAGS += $(CFLAGS_libxenctrl)
+CFLAGS += $(CFLAGS_libxenmanage)
 CFLAGS += $(CFLAGS_libxentoolcore)
 
 $(XENSTORED_OBJS-y): CFLAGS += $(CFLAGS_libxengnttab)
diff --git a/tools/xenstored/core.h b/tools/xenstored/core.h
index e58779e88c..632886cecf 100644
--- a/tools/xenstored/core.h
+++ b/tools/xenstored/core.h
@@ -19,7 +19,6 @@ 
 #ifndef _XENSTORED_CORE_H
 #define _XENSTORED_CORE_H
 
-#include <xenctrl.h>
 #include <xengnttab.h>
 
 #include <sys/types.h>
diff --git a/tools/xenstored/domain.c b/tools/xenstored/domain.c
index 64c8fd0cc3..c0264d9477 100644
--- a/tools/xenstored/domain.c
+++ b/tools/xenstored/domain.c
@@ -34,14 +34,15 @@ 
 #include "control.h"
 
 #include <xenevtchn.h>
-#include <xenctrl.h>
+#include <xenmanage.h>
+#include <xen-barrier.h>
 #include <xen/grant_table.h>
 
 #ifdef __MINIOS__
 #include <mini-os/xenbus.h>
 #endif
 
-static xc_interface **xc_handle;
+static xenmanage_handle *xm_handle;
 xengnttab_handle **xgt_handle;
 static evtchn_port_t virq_port;
 
@@ -619,32 +620,28 @@  static int destroy_domain(void *_domain)
 	return 0;
 }
 
-static bool get_domain_info(unsigned int domid, xc_domaininfo_t *dominfo)
-{
-	return xc_domain_getinfo_single(*xc_handle, domid, dominfo) == 0;
-}
-
 static int check_domain(const void *k, void *v, void *arg)
 {
-	xc_domaininfo_t dominfo;
+	unsigned int state;
 	struct connection *conn;
-	bool dom_valid;
+	int dom_invalid;
 	struct domain *domain = v;
 	bool *notify = arg;
 
-	dom_valid = get_domain_info(domain->domid, &dominfo);
+	dom_invalid = xenmanage_get_domain_info(xm_handle, domain->domid,
+						&state, NULL);
 	if (!domain->introduced) {
-		if (!dom_valid)
+		if (dom_invalid)
 			talloc_free(domain);
 		return 0;
 	}
-	if (dom_valid) {
-		if ((dominfo.flags & XEN_DOMINF_shutdown)
+	if (!dom_invalid) {
+		if ((state & XENMANAGE_GETDOMSTATE_STATE_SHUTDOWN)
 		    && !domain->shutdown) {
 			domain->shutdown = true;
 			*notify = true;
 		}
-		if (!(dominfo.flags & XEN_DOMINF_dying))
+		if (!(state & XENMANAGE_GETDOMSTATE_STATE_DYING))
 			return 0;
 	}
 	if (domain->conn) {
@@ -786,10 +783,9 @@  static struct domain *find_or_alloc_domain(const void *ctx, unsigned int domid)
 static struct domain *find_or_alloc_existing_domain(unsigned int domid)
 {
 	struct domain *domain;
-	xc_domaininfo_t dominfo;
 
 	domain = find_domain_struct(domid);
-	if (!domain && get_domain_info(domid, &dominfo))
+	if (!domain && !xenmanage_get_domain_info(xm_handle, domid, NULL, NULL))
 		domain = alloc_domain(NULL, domid);
 
 	return domain;
@@ -1187,12 +1183,6 @@  int do_reset_watches(const void *ctx, struct connection *conn,
 	return 0;
 }
 
-static int close_xc_handle(void *_handle)
-{
-	xc_interface_close(*(xc_interface**)_handle);
-	return 0;
-}
-
 static int close_xgt_handle(void *_handle)
 {
 	xengnttab_close(*(xengnttab_handle **)_handle);
@@ -1258,15 +1248,9 @@  void domain_early_init(void)
 	if (!domhash)
 		barf_perror("Failed to allocate domain hashtable");
 
-	xc_handle = talloc(talloc_autofree_context(), xc_interface*);
-	if (!xc_handle)
-		barf_perror("Failed to allocate domain handle");
-
-	*xc_handle = xc_interface_open(0,0,0);
-	if (!*xc_handle)
-		barf_perror("Failed to open connection to hypervisor");
-
-	talloc_set_destructor(xc_handle, close_xc_handle);
+	xm_handle = xenmanage_open(NULL, 0);
+	if (!xm_handle)
+		barf_perror("Failed to open connection to libxenmanage");
 
 	xgt_handle = talloc(talloc_autofree_context(), xengnttab_handle*);
 	if (!xgt_handle)
@@ -1306,6 +1290,8 @@  void domain_deinit(void)
 {
 	if (virq_port)
 		xenevtchn_unbind(xce_handle, virq_port);
+
+	xenmanage_close(xm_handle);
 }
 
 /*
@@ -1335,13 +1321,13 @@  int domain_alloc_permrefs(struct node_perms *perms)
 {
 	unsigned int i, domid;
 	struct domain *d;
-	xc_domaininfo_t dominfo;
 
 	for (i = 0; i < perms->num; i++) {
 		domid = perms->p[i].id;
 		d = find_domain_struct(domid);
 		if (!d) {
-			if (!get_domain_info(domid, &dominfo))
+			if (xenmanage_get_domain_info(xm_handle, domid,
+						      NULL, NULL))
 				perms->p[i].perms |= XS_PERM_IGNORE;
 			else if (!alloc_domain(NULL, domid))
 				return ENOMEM;
diff --git a/tools/xenstored/lu.c b/tools/xenstored/lu.c
index bec2a84e10..4fccbbc195 100644
--- a/tools/xenstored/lu.c
+++ b/tools/xenstored/lu.c
@@ -11,6 +11,7 @@ 
 #include <stdlib.h>
 #include <syslog.h>
 #include <time.h>
+#include <unistd.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 
diff --git a/tools/xenstored/lu_daemon.c b/tools/xenstored/lu_daemon.c
index 6df6c80a2a..88d8d9e1b3 100644
--- a/tools/xenstored/lu_daemon.c
+++ b/tools/xenstored/lu_daemon.c
@@ -6,6 +6,7 @@ 
  */
 
 #include <syslog.h>
+#include <unistd.h>
 #include <sys/stat.h>
 
 #include "talloc.h"