[PATCH v3 5/7] tools/libxc: add xc_vmtrace_* functions

["Michał Leszczyński" <michal.leszczynski@cert.pl>]

Add functions in libxc that use the new HVMOP_vmtrace interface.

Signed-off-by: Michal Leszczynski <michal.leszczynski@cert.pl>
---
 tools/libxc/Makefile          |  1 +
 tools/libxc/include/xenctrl.h | 39 +++++++++++++++
 tools/libxc/xc_vmtrace.c      | 94 +++++++++++++++++++++++++++++++++++
 3 files changed, 134 insertions(+)
 create mode 100644 tools/libxc/xc_vmtrace.c

diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index fae5969a73..605e44501d 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -27,6 +27,7 @@ CTRL_SRCS-y       += xc_csched2.c
 CTRL_SRCS-y       += xc_arinc653.c
 CTRL_SRCS-y       += xc_rt.c
 CTRL_SRCS-y       += xc_tbuf.c
+CTRL_SRCS-y       += xc_vmtrace.c
 CTRL_SRCS-y       += xc_pm.c
 CTRL_SRCS-y       += xc_cpu_hotplug.c
 CTRL_SRCS-y       += xc_resume.c
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 113ddd935d..66966f6c17 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1585,6 +1585,45 @@ int xc_tbuf_set_cpu_mask(xc_interface *xch, xc_cpumap_t mask);
 
 int xc_tbuf_set_evt_mask(xc_interface *xch, uint32_t mask);
 
+/**
+ * Enable processor trace for given vCPU in given DomU.
+ * Allocate the trace ringbuffer with given size.
+ *
+ * @parm xch a handle to an open hypervisor interface
+ * @parm domid domain identifier
+ * @parm vcpu vcpu identifier
+ * @return 0 on success, -1 on failure
+ */
+int xc_vmtrace_pt_enable(xc_interface *xch, uint32_t domid,
+                         uint32_t vcpu);
+
+/**
+ * Disable processor trace for given vCPU in given DomU.
+ * Deallocate the trace ringbuffer.
+ *
+ * @parm xch a handle to an open hypervisor interface
+ * @parm domid domain identifier
+ * @parm vcpu vcpu identifier
+ * @return 0 on success, -1 on failure
+ */
+int xc_vmtrace_pt_disable(xc_interface *xch, uint32_t domid,
+                          uint32_t vcpu);
+
+/**
+ * Get current offset inside the trace ringbuffer.
+ * This allows to determine how much data was written into the buffer.
+ * Once buffer overflows, the offset will reset to 0 and the previous
+ * data will be overriden.
+ *
+ * @parm xch a handle to an open hypervisor interface
+ * @parm domid domain identifier
+ * @parm vcpu vcpu identifier
+ * @parm offset current offset inside trace buffer will be written there
+ * @return 0 on success, -1 on failure
+ */
+int xc_vmtrace_pt_get_offset(xc_interface *xch, uint32_t domid,
+                             uint32_t vcpu, uint64_t *offset);
+
 int xc_domctl(xc_interface *xch, struct xen_domctl *domctl);
 int xc_sysctl(xc_interface *xch, struct xen_sysctl *sysctl);
 
diff --git a/tools/libxc/xc_vmtrace.c b/tools/libxc/xc_vmtrace.c
new file mode 100644
index 0000000000..79aad2d9a8
--- /dev/null
+++ b/tools/libxc/xc_vmtrace.c
@@ -0,0 +1,94 @@
+/******************************************************************************
+ * xc_vmtrace.c
+ *
+ * API for manipulating hardware tracing features
+ *
+ * Copyright (c) 2020, Michal Leszczynski
+ *
+ * Copyright 2020 CERT Polska. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "xc_private.h"
+#include <xen/trace.h>
+
+int xc_vmtrace_pt_enable(
+        xc_interface *xch, uint32_t domid, uint32_t vcpu)
+{
+    DECLARE_HYPERCALL_BUFFER(xen_hvm_vmtrace_op_t, arg);
+    int rc = -1;
+
+    arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
+    if ( arg == NULL )
+        return -1;
+
+    arg->cmd = HVMOP_vmtrace_pt_enable;
+    arg->domain = domid;
+    arg->vcpu = vcpu;
+
+    rc = xencall2(xch->xcall, __HYPERVISOR_hvm_op, HVMOP_vmtrace,
+                  HYPERCALL_BUFFER_AS_ARG(arg));
+
+    xc_hypercall_buffer_free(xch, arg);
+    return rc;
+}
+
+int xc_vmtrace_pt_get_offset(
+        xc_interface *xch, uint32_t domid, uint32_t vcpu, uint64_t *offset)
+{
+    DECLARE_HYPERCALL_BUFFER(xen_hvm_vmtrace_op_t, arg);
+    int rc = -1;
+
+    arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
+    if ( arg == NULL )
+        return -1;
+
+    arg->cmd = HVMOP_vmtrace_pt_get_offset;
+    arg->domain = domid;
+    arg->vcpu = vcpu;
+
+    rc = xencall2(xch->xcall, __HYPERVISOR_hvm_op, HVMOP_vmtrace,
+                  HYPERCALL_BUFFER_AS_ARG(arg));
+
+    if ( rc == 0 )
+    {
+        *offset = arg->offset;
+    }
+
+    xc_hypercall_buffer_free(xch, arg);
+    return rc;
+}
+
+int xc_vmtrace_pt_disable(xc_interface *xch, uint32_t domid, uint32_t vcpu)
+{
+    DECLARE_HYPERCALL_BUFFER(xen_hvm_vmtrace_op_t, arg);
+    int rc = -1;
+
+    arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
+    if ( arg == NULL )
+        return -1;
+
+    arg->cmd = HVMOP_vmtrace_pt_disable;
+    arg->domain = domid;
+    arg->vcpu = vcpu;
+
+    rc = xencall2(xch->xcall, __HYPERVISOR_hvm_op, HVMOP_vmtrace,
+                  HYPERCALL_BUFFER_AS_ARG(arg));
+
+    xc_hypercall_buffer_free(xch, arg);
+    return rc;
+}
+
-- 
2.20.1