As both xen-netfront and xen-blkfront support multi-queue, they would
consume a lot of grant table references when there are many paravirtual
devices and vcpus assigned to guest. Guest domU might panic or hang due to
grant allocation failure when nr_grant_frames in guest has reached its max
value.
This utility would help the administrators to diagnose xen issue. There is
only one command gnttab_query_size so far to monitor the guest grant table
frame usage on dom0 side so that it is not required to debug on guest
kernel side for crash/hang analysis anymore.
It is extensible for adding new commands for more diagnostic functions and
the framework of xen-diag.c is from xen-livepatch.c.
Signed-off-by: Dongli Zhang
---
Changed since v1:
* rewrite xen-gnttab-query.c to xen-diag.c based on livepatch.c framework
---
tools/misc/Makefile | 4 ++
tools/misc/xen-diag.c | 129 ++
2 files changed, 133 insertions(+)
create mode 100644 tools/misc/xen-diag.c
diff --git a/tools/misc/Makefile b/tools/misc/Makefile
index 8152f7b..c1113b9 100644
--- a/tools/misc/Makefile
+++ b/tools/misc/Makefile
@@ -31,6 +31,7 @@ INSTALL_SBIN += xenperf
INSTALL_SBIN += xenpm
INSTALL_SBIN += xenwatchdogd
INSTALL_SBIN += xen-livepatch
+INSTALL_SBIN += xen-diag
INSTALL_SBIN += $(INSTALL_SBIN-y)
# Everything to be installed in a private bin/
@@ -102,6 +103,9 @@ xenwatchdogd: xenwatchdogd.o
xen-livepatch: xen-livepatch.o
$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
+xen-diag: xen-diag.o
+ $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
+
xen-lowmemd: xen-lowmemd.o
$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenevtchn) $(LDLIBS_libxenctrl)
$(LDLIBS_libxenstore) $(APPEND_LDFLAGS)
diff --git a/tools/misc/xen-diag.c b/tools/misc/xen-diag.c
new file mode 100644
index 000..1da50e1
--- /dev/null
+++ b/tools/misc/xen-diag.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+#include
+
+static xc_interface *xch;
+
+#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
+
+void show_help(void)
+{
+fprintf(stderr,
+"xen-diag: xen diagnostic utility\n"
+"Usage: xen-diag command [args]\n"
+"Commands:\n"
+" help display this help\n"
+" gnttab_query_size dump the current and max grant
frames for \n");
+}
+
+/* wrapper function */
+static int help_func(int argc, char *argv[])
+{
+show_help();
+return 0;
+}
+
+static int gnttab_query_size_func(int argc, char *argv[])
+{
+int domid, rc = 1;
+struct gnttab_query_size query;
+
+if ( argc != 1 )
+{
+show_help();
+return rc;
+}
+
+domid = strtol(argv[0], NULL, 10);
+query.dom = domid;
+rc = xc_gnttab_query_size(xch, );
+
+if ( rc == 0 && (query.status == GNTST_okay) )
+printf("domid=%d: nr_frames=%d, max_nr_frames=%d\n",
+ query.dom, query.nr_frames, query.max_nr_frames);
+
+return rc == 0 && (query.status == GNTST_okay) ? 0 : 1;
+}
+
+struct {
+const char *name;
+int (*function)(int argc, char *argv[]);
+} main_options[] = {
+{ "help", help_func },
+{ "gnttab_query_size", gnttab_query_size_func},
+};
+
+int main(int argc, char *argv[])
+{
+int ret, i;
+
+/*
+ * Set stdout to be unbuffered to avoid having to fflush when
+ * printing without a newline.
+ */
+setvbuf(stdout, NULL, _IONBF, 0);
+
+if ( argc <= 1 )
+{
+show_help();
+return 0;
+}
+
+for ( i = 0; i < ARRAY_SIZE(main_options); i++ )
+if ( !strncmp(main_options[i].name, argv[1], strlen(argv[1])) )
+break;
+
+if ( i == ARRAY_SIZE(main_options) )
+{
+show_help();
+return 0;
+}
+else
+{
+xch = xc_interface_open(0, 0, 0);
+if ( !xch )
+{
+fprintf(stderr, "failed to get the handler\n");
+return 0;
+}
+
+ret = main_options[i].function(argc - 2, argv + 2);
+
+xc_interface_close(xch);
+}
+
+/*
+ * Exitcode 0 for success.
+ * Exitcode 1 for an error.
+ * Exitcode 2 if the operation should be retried for any reason (e.g. a
+ * timeout or because another operation was in progress).
+ */
+
+#define EXIT_TIMEOUT (EXIT_FAILURE + 1)
+
+BUILD_BUG_ON(EXIT_SUCCESS != 0);
+BUILD_BUG_ON(EXIT_FAILURE != 1);
+BUILD_BUG_ON(EXIT_TIMEOUT != 2);
+
+switch ( ret )
+{
+case 0:
+return EXIT_SUCCESS;
+case EAGAIN:
+case EBUSY:
+return EXIT_TIMEOUT;
+default:
+return EXIT_FAILURE;
+}
+}
--
2.7.4
___