[PATCH v9 08/11] tools/misc: Add xen-vmtrace tool

[Andrew Cooper <andrew.cooper3@citrix.com>]

From: Michał Leszczyński <michal.leszczynski@cert.pl>

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

Signed-off-by: Michał Leszczyński <michal.leszczynski@cert.pl>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
---
CC: Ian Jackson <iwj@xenproject.org>
CC: Wei Liu <wl@xen.org>
CC: Michał Leszczyński <michal.leszczynski@cert.pl>
CC: Tamas K Lengyel <tamas@tklengyel.com>

v9:
 * Fix truncated data on clean exit

v8:
 * Switch to being a build-only target
---
 tools/misc/.gitignore    |   1 +
 tools/misc/Makefile      |   7 ++
 tools/misc/xen-vmtrace.c | 166 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 174 insertions(+)
 create mode 100644 tools/misc/xen-vmtrace.c

diff --git a/tools/misc/.gitignore b/tools/misc/.gitignore
index b2c3b21f57..ce6f937d0c 100644
--- a/tools/misc/.gitignore
+++ b/tools/misc/.gitignore
@@ -1,3 +1,4 @@
 xen-access
 xen-memshare
 xen-ucode
+xen-vmtrace
diff --git a/tools/misc/Makefile b/tools/misc/Makefile
index 912c5d4f0e..2b683819d4 100644
--- a/tools/misc/Makefile
+++ b/tools/misc/Makefile
@@ -50,6 +50,10 @@ TARGETS_COPY += xenpvnetboot
 # Everything which needs to be built
 TARGETS_BUILD := $(filter-out $(TARGETS_COPY),$(TARGETS_ALL))
 
+# ... including build-only targets
+TARGETS_BUILD-$(CONFIG_X86)    += xen-vmtrace
+TARGETS_BUILD += $(TARGETS_BUILD-y)
+
 .PHONY: all build
 all build: $(TARGETS_BUILD)
 
@@ -90,6 +94,9 @@ xen-hvmcrash: xen-hvmcrash.o
 xen-memshare: xen-memshare.o
 	$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
 
+xen-vmtrace: xen-vmtrace.o
+	$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(LDLIBS_libxenforeignmemory) $(APPEND_LDFLAGS)
+
 xenperf: xenperf.o
 	$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
 
diff --git a/tools/misc/xen-vmtrace.c b/tools/misc/xen-vmtrace.c
new file mode 100644
index 0000000000..cc58a0707b
--- /dev/null
+++ b/tools/misc/xen-vmtrace.c
@@ -0,0 +1,166 @@
+/******************************************************************************
+ * tools/vmtrace.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@cert.pl
+ * 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 <err.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+
+#include <xenctrl.h>
+#include <xenforeignmemory.h>
+
+#define MSR_RTIT_CTL                        0x00000570
+#define  RTIT_CTL_OS                        (1 <<  2)
+#define  RTIT_CTL_USR                       (1 <<  3)
+#define  RTIT_CTL_BRANCH_EN                 (1 << 13)
+
+static xc_interface *xch;
+static xenforeignmemory_handle *fh;
+static uint32_t domid, vcpu;
+static size_t size;
+static char *buf;
+
+static sig_atomic_t interrupted = 0;
+static void int_handler(int signum)
+{
+    interrupted = 1;
+}
+
+static int get_more_data(void)
+{
+    static uint64_t last_pos;
+    uint64_t pos;
+
+    if ( xc_vmtrace_output_position(xch, domid, vcpu, &pos) )
+    {
+        perror("xc_vmtrace_output_position()");
+        return -1;
+    }
+
+    if ( pos > last_pos )
+        fwrite(buf + last_pos, pos - last_pos, 1, stdout);
+    else if ( pos < last_pos )
+    {
+        /* buffer wrapped */
+        fwrite(buf + last_pos, size - last_pos, 1, stdout);
+        fwrite(buf, pos, 1, stdout);
+    }
+
+    last_pos = pos;
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    int rc, exit = 1;
+    xenforeignmemory_resource_handle *fres = NULL;
+
+    if ( signal(SIGINT, int_handler) == SIG_ERR )
+        err(1, "Failed to register signal handler\n");
+
+    if ( argc != 3 )
+    {
+        fprintf(stderr, "Usage: %s <domid> <vcpu_id>\n", argv[0]);
+        fprintf(stderr, "It's recommended to redirect thisprogram'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  = atoi(argv[2]);
+
+    xch = xc_interface_open(NULL, NULL, 0);
+    fh = xenforeignmemory_open(NULL, 0);
+
+    if ( !xch )
+        err(1, "xc_interface_open()");
+    if ( !fh )
+        err(1, "xenforeignmemory_open()");
+
+    rc = xenforeignmemory_resource_size(
+        fh, domid, XENMEM_resource_vmtrace_buf, vcpu, &size);
+    if ( rc )
+        err(1, "xenforeignmemory_resource_size()");
+
+    fres = xenforeignmemory_map_resource(
+        fh, domid, XENMEM_resource_vmtrace_buf, vcpu,
+        0, size >> XC_PAGE_SHIFT, (void **)&buf, PROT_READ, 0);
+    if ( !fres )
+        err(1, "xenforeignmemory_map_resource()");
+
+    if ( xc_vmtrace_set_option(
+             xch, domid, vcpu, MSR_RTIT_CTL,
+             RTIT_CTL_BRANCH_EN | RTIT_CTL_USR | RTIT_CTL_OS) )
+    {
+        perror("xc_vmtrace_set_option()");
+        goto out;
+    }
+
+    if ( xc_vmtrace_enable(xch, domid, vcpu) )
+    {
+        perror("xc_vmtrace_enable()");
+        goto out;
+    }
+
+    while ( !interrupted )
+    {
+        xc_dominfo_t dominfo;
+
+        if ( get_more_data() )
+            goto out;
+
+        usleep(1000 * 100);
+
+        if ( xc_domain_getinfo(xch, domid, 1, &dominfo) != 1 ||
+             dominfo.domid != domid || dominfo.shutdown )
+        {
+            if ( get_more_data() )
+                goto out;
+            break;
+        }
+    }
+
+    exit = 0;
+
+ out:
+    if ( xc_vmtrace_disable(xch, domid, vcpu) )
+        perror("xc_vmtrace_disable()");
+
+    if ( fres && xenforeignmemory_unmap_resource(fh, fres) )
+        perror("xenforeignmemory_unmap_resource()");
+
+    return exit;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.11.0