[RFC PATCH 2/2] tools/misc: Add xen-stats tool

[Matias Ezequiel Vara Larsen <matiasevara@xxxxxxxxx>]

Add a demostration tool that uses the stats_table resource to
query vcpu time for a DomU.

Signed-off-by: Matias Ezequiel Vara Larsen <matias.vara@xxxxxxxx>
---
 tools/misc/Makefile    |  5 +++
 tools/misc/xen-stats.c | 83 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 tools/misc/xen-stats.c

diff --git a/tools/misc/Makefile b/tools/misc/Makefile
index 2b683819d4..b510e3aceb 100644
--- a/tools/misc/Makefile
+++ b/tools/misc/Makefile
@@ -135,4 +135,9 @@ xencov: xencov.o
 xen-ucode: xen-ucode.o
        $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
 
+xen-stats.o: CFLAGS += $(CFLAGS_libxenforeginmemory)
+
+xen-stats: xen-stats.o
+       $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) 
$(LDLIBS_libxenforeignmemory) $(APPEND_LDFLAGS)
+
 -include $(DEPS_INCLUDE)
diff --git a/tools/misc/xen-stats.c b/tools/misc/xen-stats.c
new file mode 100644
index 0000000000..5d4a3239cc
--- /dev/null
+++ b/tools/misc/xen-stats.c
@@ -0,0 +1,83 @@
+#include <err.h>
+#include <errno.h>
+#include <error.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <signal.h>
+
+#include <xenctrl.h>
+#include <xenforeignmemory.h>
+#include <xen-tools/libs.h>
+
+static sig_atomic_t interrupted;
+static void close_handler(int signum)
+{
+    interrupted = 1;
+}
+
+int main(int argc, char **argv)
+{
+    xenforeignmemory_handle *fh;
+    xenforeignmemory_resource_handle *res;
+    size_t size;
+    int rc, nr_frames, domid, frec, vcpu;
+    uint64_t * info;
+    struct sigaction act;
+
+    if (argc != 4 ) {
+        fprintf(stderr, "Usage: %s <domid> <vcpu> <period>\n", argv[0]);
+        return 1;
+    }
+
+    // TODO: this depends on the resource
+    nr_frames = 1;
+
+    domid = atoi(argv[1]);
+    frec = atoi(argv[3]);
+    vcpu = atoi(argv[2]);
+
+    act.sa_handler = close_handler;
+    act.sa_flags = 0;
+    sigemptyset(&act.sa_mask);
+    sigaction(SIGHUP,  &act, NULL);
+    sigaction(SIGTERM, &act, NULL);
+    sigaction(SIGINT,  &act, NULL);
+    sigaction(SIGALRM, &act, NULL);
+
+    fh = xenforeignmemory_open(NULL, 0);
+
+    if ( !fh )
+        err(1, "xenforeignmemory_open");
+
+    rc = xenforeignmemory_resource_size(
+        fh, domid, XENMEM_resource_stats_table,
+        vcpu, &size);
+
+    if ( rc )
+        err(1, "    Fail: Get size: %d - %s\n", errno, strerror(errno));
+
+    if ( (size >> XC_PAGE_SHIFT) != nr_frames )
+        err(1, "    Fail: Get size: expected %u frames, got %zu\n",
+                    nr_frames, size >> XC_PAGE_SHIFT);
+
+    res = xenforeignmemory_map_resource(
+        fh, domid, XENMEM_resource_stats_table,
+        vcpu, 0, size >> XC_PAGE_SHIFT,
+        (void **)&info, PROT_READ, 0);
+
+    if ( !res )
+        err(1, "    Fail: Map %d - %s\n", errno, strerror(errno));
+
+    while ( !interrupted ) {
+        sleep(frec);
+        printf("running cpu_time: %ld\n", *info);
+    }
+
+    rc = xenforeignmemory_unmap_resource(fh, res);
+    if ( rc )
+        err(1, "    Fail: Unmap %d - %s\n", errno, strerror(errno));
+
+    return 0;
+}
-- 
2.25.1