[PATCH v3 6/7] tools/libxl: add vmtrace_pt_size parameter

[Michał Leszczyński <michal.leszczynski@xxxxxxx>]

Allow to specify the size of per-vCPU trace buffer upon
domain creation. This is zero by default (meaning: not enabled).

Signed-off-by: Michal Leszczynski <michal.leszczynski@xxxxxxx>
---
 docs/man/xl.cfg.5.pod.in             | 10 ++++++++++
 tools/golang/xenlight/helpers.gen.go |  2 ++
 tools/golang/xenlight/types.gen.go   |  1 +
 tools/libxl/libxl_create.c           |  1 +
 tools/libxl/libxl_types.idl          |  2 ++
 tools/xl/xl_parse.c                  |  4 ++++
 6 files changed, 20 insertions(+)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index 0532739c1f..78f434b722 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -278,6 +278,16 @@ memory=8096 will report significantly less memory 
available for use
 than a system with maxmem=8096 memory=8096 due to the memory overhead
 of having to track the unused pages.
 
+=item B<vmtrace_pt_size=BYTES>
+
+Specifies the size of processor trace buffer that would be allocated
+for each vCPU belonging to this domain. Disabled (i.e. B<vmtrace_pt_size=0>
+by default. This must be set to non-zero value in order to be able to
+use processor tracing features with this domain.
+
+B<NOTE>: The size value must be between 4 kB and 4 GB and it must
+be also a power of 2.
+
 =back
 
 =head3 Guest Virtual NUMA Configuration
diff --git a/tools/golang/xenlight/helpers.gen.go 
b/tools/golang/xenlight/helpers.gen.go
index 935d3bc50a..986ebbd681 100644
--- a/tools/golang/xenlight/helpers.gen.go
+++ b/tools/golang/xenlight/helpers.gen.go
@@ -1117,6 +1117,7 @@ return fmt.Errorf("invalid union key '%v'", x.Type)}
 x.ArchArm.GicVersion = GicVersion(xc.arch_arm.gic_version)
 x.ArchArm.Vuart = VuartType(xc.arch_arm.vuart)
 x.Altp2M = Altp2MMode(xc.altp2m)
+x.VmtracePtSize = int(xc.vmtrace_pt_size)
 
  return nil}
 
@@ -1592,6 +1593,7 @@ return fmt.Errorf("invalid union key '%v'", x.Type)}
 xc.arch_arm.gic_version = C.libxl_gic_version(x.ArchArm.GicVersion)
 xc.arch_arm.vuart = C.libxl_vuart_type(x.ArchArm.Vuart)
 xc.altp2m = C.libxl_altp2m_mode(x.Altp2M)
+xc.vmtrace_pt_size = C.int(x.VmtracePtSize)
 
  return nil
  }
diff --git a/tools/golang/xenlight/types.gen.go 
b/tools/golang/xenlight/types.gen.go
index 663c1e86b4..41ec7cdd32 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -516,6 +516,7 @@ GicVersion GicVersion
 Vuart VuartType
 }
 Altp2M Altp2MMode
+VmtracePtSize int
 }
 
 type domainBuildInfoTypeUnion interface {
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 75862dc6ed..32204b83b0 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -608,6 +608,7 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config 
*d_config,
             .max_evtchn_port = b_info->event_channels,
             .max_grant_frames = b_info->max_grant_frames,
             .max_maptrack_frames = b_info->max_maptrack_frames,
+            .vmtrace_pt_size = b_info->vmtrace_pt_size,
         };
 
         if (info->type != LIBXL_DOMAIN_TYPE_PV) {
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 9d3f05f399..04c1704b72 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -645,6 +645,8 @@ libxl_domain_build_info = Struct("domain_build_info",[
     # supported by x86 HVM and ARM support is planned.
     ("altp2m", libxl_altp2m_mode),
 
+    ("vmtrace_pt_size", integer),
+
     ], dir=DIR_IN,
        copy_deprecated_fn="libxl__domain_build_info_copy_deprecated",
 )
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 61b4ef7b7e..6ab98dda55 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -1861,6 +1861,10 @@ void parse_config_data(const char *config_source,
         }
     }
 
+    if (!xlu_cfg_get_long(config, "vmtrace_pt_size", &l, 1)) {
+        b_info->vmtrace_pt_size = l;
+    }
+
     if (!xlu_cfg_get_list(config, "ioports", &ioports, &num_ioports, 0)) {
         b_info->num_ioports = num_ioports;
         b_info->ioports = calloc(num_ioports, sizeof(*b_info->ioports));
-- 
2.20.1