[PATCH v6 11/11] tools/proctrace: add proctrace tool

[Michał Leszczyński <michal.leszczynski@xxxxxxx>]

From: Michal Leszczynski <michal.leszczynski@xxxxxxx>

Add an demonstration tool that uses xc_vmtrace_* calls in order
to manage external IPT monitoring for DomU.

Signed-off-by: Michal Leszczynski <michal.leszczynski@xxxxxxx>
---
 tools/proctrace/Makefile    |  45 +++++++++
 tools/proctrace/proctrace.c | 179 ++++++++++++++++++++++++++++++++++++
 2 files changed, 224 insertions(+)
 create mode 100644 tools/proctrace/Makefile
 create mode 100644 tools/proctrace/proctrace.c

diff --git a/tools/proctrace/Makefile b/tools/proctrace/Makefile
new file mode 100644
index 0000000000..9c135229b9
--- /dev/null
+++ b/tools/proctrace/Makefile
@@ -0,0 +1,45 @@
+# Copyright (C) CERT Polska - NASK PIB
+# Author: Michał Leszczyński <michal.leszczynski@xxxxxxx>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; under version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+XEN_ROOT=$(CURDIR)/../..
+include $(XEN_ROOT)/tools/Rules.mk
+
+CFLAGS  += -Werror
+CFLAGS  += $(CFLAGS_libxenevtchn)
+CFLAGS  += $(CFLAGS_libxenctrl)
+LDLIBS  += $(LDLIBS_libxenctrl)
+LDLIBS  += $(LDLIBS_libxenevtchn)
+LDLIBS  += $(LDLIBS_libxenforeignmemory)
+
+.PHONY: all
+all: build
+
+.PHONY: build
+build: proctrace
+
+.PHONY: install
+install: build
+       $(INSTALL_DIR) $(DESTDIR)$(sbindir)
+       $(INSTALL_PROG) proctrace $(DESTDIR)$(sbindir)/proctrace
+
+.PHONY: uninstall
+uninstall:
+       rm -f $(DESTDIR)$(sbindir)/proctrace
+
+.PHONY: clean
+clean:
+       $(RM) -f proctrace $(DEPS_RM)
+
+.PHONY: distclean
+distclean: clean
+
+-include $(DEPS_INCLUDE)
diff --git a/tools/proctrace/proctrace.c b/tools/proctrace/proctrace.c
new file mode 100644
index 0000000000..3c1ccccee8
--- /dev/null
+++ b/tools/proctrace/proctrace.c
@@ -0,0 +1,179 @@
+/******************************************************************************
+ * tools/proctrace.c
+ *
+ * Demonstrative tool for collecting Intel Processor Trace data from Xen.
+ *  Could be used to externally monitor a given vCPU in given DomU.
+ *
+ * Copyright (C) 2020 by CERT Polska - NASK PIB
+ *
+ * Authors: Michał Leszczyński, michal.leszczynski@xxxxxxx
+ * Date:    June, 2020
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <signal.h>
+#include <errno.h>
+
+#include <xenctrl.h>
+#include <xen/xen.h>
+#include <xenforeignmemory.h>
+
+volatile int interrupted = 0;
+volatile int domain_down = 0;
+
+void term_handler(int signum) {
+    interrupted = 1;
+}
+
+int main(int argc, char* argv[]) {
+    xc_interface *xc;
+    uint32_t domid;
+    uint32_t vcpu_id;
+    uint64_t size;
+
+    int rc = -1;
+    uint8_t *buf = NULL;
+    uint64_t last_offset = 0;
+
+    xenforeignmemory_handle *fmem;
+    xenforeignmemory_resource_handle *fres;
+
+    if (signal(SIGINT, term_handler) == SIG_ERR)
+    {
+        fprintf(stderr, "Failed to register signal handler\n");
+        return 1;
+    }
+
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <domid> <vcpu_id>\n", argv[0]);
+        fprintf(stderr, "It's recommended to redirect this"
+                        "program's output to file\n");
+        fprintf(stderr, "or to pipe it's output to xxd or other program.\n");
+        return 1;
+    }
+
+    domid = atoi(argv[1]);
+    vcpu_id = atoi(argv[2]);
+
+    xc = xc_interface_open(0, 0, 0);
+
+    fmem = xenforeignmemory_open(0, 0);
+
+    if (!xc) {
+        fprintf(stderr, "Failed to open xc interface\n");
+        return 1;
+    }
+
+    rc = xc_vmtrace_pt_enable(xc, domid, vcpu_id);
+
+    if (rc) {
+        fprintf(stderr, "Failed to call xc_vmtrace_pt_enable\n");
+        return 1;
+    }
+    
+    rc = xc_vmtrace_pt_get_offset(xc, domid, vcpu_id, NULL, &size);
+
+    if (rc) {
+        fprintf(stderr, "Failed to get trace buffer size\n");
+        return 1;
+    }
+
+    fres = xenforeignmemory_map_resource(
+        fmem, domid, XENMEM_resource_vmtrace_buf,
+        /* vcpu: */ vcpu_id,
+        /* frame: */ 0,
+        /* num_frames: */ size >> XC_PAGE_SHIFT,
+        (void **)&buf,
+        PROT_READ, 0);
+
+    if (!buf) {
+        fprintf(stderr, "Failed to map trace buffer\n");
+        return 1;
+    }
+
+    while (!interrupted) {
+        uint64_t offset;
+        rc = xc_vmtrace_pt_get_offset(xc, domid, vcpu_id, &offset, NULL);
+
+        if (rc == ENODATA) {
+            interrupted = 1;
+            domain_down = 1;
+       } else if (rc) {
+            fprintf(stderr, "Failed to call xc_vmtrace_pt_get_offset\n");
+            return 1;
+        }
+
+        if (offset > last_offset)
+        {
+            fwrite(buf + last_offset, offset - last_offset, 1, stdout);
+        }
+        else if (offset < last_offset)
+        {
+            // buffer wrapped
+            fwrite(buf + last_offset, size - last_offset, 1, stdout);
+            fwrite(buf, offset, 1, stdout);
+        }
+
+        last_offset = offset;
+        usleep(1000 * 100);
+    }
+
+    rc = xenforeignmemory_unmap_resource(fmem, fres);
+
+    if (rc) {
+        fprintf(stderr, "Failed to unmap resource\n");
+        return 1;
+    }
+
+    rc = xenforeignmemory_close(fmem);
+
+    if (rc) {
+        fprintf(stderr, "Failed to close fmem\n");
+        return 1;
+    }
+
+    /*
+     * Don't try to disable PT if the domain is already dying.
+     */
+    if (!domain_down) {
+        rc = xc_vmtrace_pt_disable(xc, domid, vcpu_id);
+
+        if (rc) {
+            fprintf(stderr, "Failed to call xc_vmtrace_pt_disable\n");
+            return 1;
+        }
+    }
+
+    rc = xc_interface_close(xc);
+
+    if (rc) {
+        fprintf(stderr, "Failed to close xc interface\n");
+        return 1;
+    }
+
+    return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.17.1