From 1f9d04fb021cbf35cc420d401a88c696d6524c14 Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Thu, 15 Sep 2011 11:08:05 +0100 Subject: [PATCH] xenstored: allow guest to shutdown all its watches/transactions During kexec all old watches have to be removed, otherwise the new kernel will receive unexpected events. Allow a guest to reset itself and cleanup all of its watches and transactions. Add a new XS_RESET_WATCHES command to do the reset on behalf of the guest. (Changes by iwj: specify the argument to be a single nul byte. Permit read-only clients to use the new command.) Signed-off-by: Olaf Hering Signed-off-by: Ian Jackson Committed-by: Ian Jackson --- docs/misc/xenstore.txt | 3 +++ tools/xenstore/xenstored_core.c | 5 +++++ tools/xenstore/xenstored_domain.c | 9 +++++++++ tools/xenstore/xenstored_domain.h | 3 +++ xen/include/public/io/xs_wire.h | 3 ++- 5 files changed, 22 insertions(+), 1 deletion(-) diff --git a/docs/misc/xenstore.txt b/docs/misc/xenstore.txt index f46cf4f525..9f3087d2ea 100644 --- a/docs/misc/xenstore.txt +++ b/docs/misc/xenstore.txt @@ -217,6 +217,9 @@ WATCH_EVENT || UNWATCH ||? +RESET_WATCHES | + Reset all watches and transactions of the caller. + ---------- Transactions ---------- TRANSACTION_START | | diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index 3b1955a5c0..5d308cad86 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -120,6 +120,7 @@ static char *sockmsg_string(enum xsd_sockmsg_type type) case XS_IS_DOMAIN_INTRODUCED: return "XS_IS_DOMAIN_INTRODUCED"; case XS_RESUME: return "RESUME"; case XS_SET_TARGET: return "SET_TARGET"; + case XS_RESET_WATCHES: return "RESET_WATCHES"; default: return "**UNKNOWN**"; } @@ -1242,6 +1243,10 @@ static void process_message(struct connection *conn, struct buffered_data *in) do_set_target(conn, in); break; + case XS_RESET_WATCHES: + do_reset_watches(conn); + break; + default: eprintf("Client unknown operation %i", in->hdr.msg.type); send_error(conn, ENOSYS); diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c index 654185d4bb..443af8250a 100644 --- a/tools/xenstore/xenstored_domain.c +++ b/tools/xenstore/xenstored_domain.c @@ -537,6 +537,15 @@ void do_is_domain_introduced(struct connection *conn, const char *domid_str) send_reply(conn, XS_IS_DOMAIN_INTRODUCED, result ? "T" : "F", 2); } +/* Allow guest to reset all watches */ +void do_reset_watches(struct connection *conn) +{ + conn_delete_all_watches(conn); + conn_delete_all_transactions(conn); + + send_ack(conn, XS_RESET_WATCHES); +} + static int close_xc_handle(void *_handle) { xc_interface_close(*(xc_interface**)_handle); diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h index 6a1e8be09b..9e2afaea5e 100644 --- a/tools/xenstore/xenstored_domain.h +++ b/tools/xenstore/xenstored_domain.h @@ -40,6 +40,9 @@ void do_set_target(struct connection *conn, struct buffered_data *in); /* domid */ void do_get_domain_path(struct connection *conn, const char *domid_str); +/* Allow guest to reset all watches */ +void do_reset_watches(struct connection *conn); + void domain_init(void); /* Returns the implicit path of a connection (only domains have this) */ diff --git a/xen/include/public/io/xs_wire.h b/xen/include/public/io/xs_wire.h index e1debceb63..7e454c4b99 100644 --- a/xen/include/public/io/xs_wire.h +++ b/xen/include/public/io/xs_wire.h @@ -48,7 +48,8 @@ enum xsd_sockmsg_type XS_IS_DOMAIN_INTRODUCED, XS_RESUME, XS_SET_TARGET, - XS_RESTRICT + XS_RESTRICT, + XS_RESET_WATCHES }; #define XS_WRITE_NONE "NONE" -- 2.39.5