[PATCH v7 01/10] xen+tools: Introduce XEN_SYSCTL_PHYSCAP_vmtrace

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

We're about to introduce support for Intel Processor Trace, but similar
functionality exists in other platforms.

Aspects of vmtrace can reasonably can be common, so start with
XEN_SYSCTL_PHYSCAP_vmtrace and plumb the signal from Xen all the way down into
`xl info`.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Ian Jackson <iwj@xxxxxxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Michał Leszczyński <michal.leszczynski@xxxxxxx>
CC: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>

v7:
 * New
---
 tools/golang/xenlight/helpers.gen.go | 2 ++
 tools/golang/xenlight/types.gen.go   | 1 +
 tools/include/libxl.h                | 7 +++++++
 tools/libs/light/libxl.c             | 2 ++
 tools/libs/light/libxl_types.idl     | 1 +
 tools/xl/xl_info.c                   | 5 +++--
 xen/common/domain.c                  | 2 ++
 xen/common/sysctl.c                  | 2 ++
 xen/include/public/sysctl.h          | 1 +
 xen/include/xen/domain.h             | 2 ++
 10 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/tools/golang/xenlight/helpers.gen.go 
b/tools/golang/xenlight/helpers.gen.go
index c8605994e7..62fb98ba30 100644
--- a/tools/golang/xenlight/helpers.gen.go
+++ b/tools/golang/xenlight/helpers.gen.go
@@ -3345,6 +3345,7 @@ x.CapHvmDirectio = bool(xc.cap_hvm_directio)
 x.CapHap = bool(xc.cap_hap)
 x.CapShadow = bool(xc.cap_shadow)
 x.CapIommuHapPtShare = bool(xc.cap_iommu_hap_pt_share)
+x.CapVmtrace = bool(xc.cap_vmtrace)
 
  return nil}
 
@@ -3375,6 +3376,7 @@ xc.cap_hvm_directio = C.bool(x.CapHvmDirectio)
 xc.cap_hap = C.bool(x.CapHap)
 xc.cap_shadow = C.bool(x.CapShadow)
 xc.cap_iommu_hap_pt_share = C.bool(x.CapIommuHapPtShare)
+xc.cap_vmtrace = C.bool(x.CapVmtrace)
 
  return nil
  }
diff --git a/tools/golang/xenlight/types.gen.go 
b/tools/golang/xenlight/types.gen.go
index b4c5df0f2c..369da6dd1e 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -998,6 +998,7 @@ CapHvmDirectio bool
 CapHap bool
 CapShadow bool
 CapIommuHapPtShare bool
+CapVmtrace bool
 }
 
 type Connectorinfo struct {
diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index 3433c950f9..c4d920f1e5 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -464,6 +464,13 @@
 #define LIBXL_HAVE_DEVICE_PCI_ASSIGNABLE_LIST_FREE 1
 
 /*
+ * LIBXL_HAVE_PHYSINFO_CAP_VMTRACE indicates that libxl_physinfo has a
+ * cap_vmtrace field, which indicates the availability of platform tracing
+ * functionality.
+ */
+#define LIBXL_HAVE_PHYSINFO_CAP_VMTRACE 1
+
+/*
  * libxl ABI compatibility
  *
  * The only guarantee which libxl makes regarding ABI compatibility
diff --git a/tools/libs/light/libxl.c b/tools/libs/light/libxl.c
index d2a87157a2..204eb0be2d 100644
--- a/tools/libs/light/libxl.c
+++ b/tools/libs/light/libxl.c
@@ -402,6 +402,8 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo 
*physinfo)
         !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_shadow);
     physinfo->cap_iommu_hap_pt_share =
         !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_iommu_hap_pt_share);
+    physinfo->cap_vmtrace =
+        !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_vmtrace);
 
     GC_FREE;
     return 0;
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 05324736b7..b43d5f1265 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -1050,6 +1050,7 @@ libxl_physinfo = Struct("physinfo", [
     ("cap_hap", bool),
     ("cap_shadow", bool),
     ("cap_iommu_hap_pt_share", bool),
+    ("cap_vmtrace", bool),
     ], dir=DIR_OUT)
 
 libxl_connectorinfo = Struct("connectorinfo", [
diff --git a/tools/xl/xl_info.c b/tools/xl/xl_info.c
index ca417df8e8..8383e4a6df 100644
--- a/tools/xl/xl_info.c
+++ b/tools/xl/xl_info.c
@@ -210,14 +210,15 @@ static void output_physinfo(void)
          info.hw_cap[4], info.hw_cap[5], info.hw_cap[6], info.hw_cap[7]
         );
 
-    maybe_printf("virt_caps              :%s%s%s%s%s%s%s\n",
+    maybe_printf("virt_caps              :%s%s%s%s%s%s%s%s\n",
          info.cap_pv ? " pv" : "",
          info.cap_hvm ? " hvm" : "",
          info.cap_hvm && info.cap_hvm_directio ? " hvm_directio" : "",
          info.cap_pv && info.cap_hvm_directio ? " pv_directio" : "",
          info.cap_hap ? " hap" : "",
          info.cap_shadow ? " shadow" : "",
-         info.cap_iommu_hap_pt_share ? " iommu_hap_pt_share" : ""
+         info.cap_iommu_hap_pt_share ? " iommu_hap_pt_share" : "",
+         info.cap_vmtrace ? " vmtrace" : ""
         );
 
     vinfo = libxl_get_version_info(ctx);
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 2b461655c3..d1e94d88cf 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -82,6 +82,8 @@ struct vcpu *idle_vcpu[NR_CPUS] __read_mostly;
 
 vcpu_info_t dummy_vcpu_info;
 
+bool __read_mostly vmtrace_available;
+
 static void __domain_finalise_shutdown(struct domain *d)
 {
     struct vcpu *v;
diff --git a/xen/common/sysctl.c b/xen/common/sysctl.c
index ec916424e5..3558641cd9 100644
--- a/xen/common/sysctl.c
+++ b/xen/common/sysctl.c
@@ -277,6 +277,8 @@ long do_sysctl(XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) 
u_sysctl)
             if ( iommu_hap_pt_share )
                 pi->capabilities |= XEN_SYSCTL_PHYSCAP_iommu_hap_pt_share;
         }
+        if ( vmtrace_available )
+            pi->capabilities |= XEN_SYSCTL_PHYSCAP_vmtrace;
 
         if ( copy_to_guest(u_sysctl, op, 1) )
             ret = -EFAULT;
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index a073647117..d4453d2eab 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -100,6 +100,7 @@ struct xen_sysctl_tbuf_op {
 #define _XEN_SYSCTL_PHYSCAP_iommu_hap_pt_share 5
 #define XEN_SYSCTL_PHYSCAP_iommu_hap_pt_share  \
     (1u << _XEN_SYSCTL_PHYSCAP_iommu_hap_pt_share)
+#define XEN_SYSCTL_PHYSCAP_vmtrace       (1 << 6)
 
 /* Max XEN_SYSCTL_PHYSCAP_* constant.  Used for ABI checking. */
 #define XEN_SYSCTL_PHYSCAP_MAX XEN_SYSCTL_PHYSCAP_iommu_hap_pt_share
diff --git a/xen/include/xen/domain.h b/xen/include/xen/domain.h
index cde0d9c7fe..1708c36964 100644
--- a/xen/include/xen/domain.h
+++ b/xen/include/xen/domain.h
@@ -131,4 +131,6 @@ void vnuma_destroy(struct vnuma_info *vnuma);
 static inline void vnuma_destroy(struct vnuma_info *vnuma) { ASSERT(!vnuma); }
 #endif
 
+extern bool vmtrace_available;
+
 #endif /* __XEN_DOMAIN_H__ */
-- 
2.11.0