From 0aa64f1929a0407c71d0ff948524ac038646240a Mon Sep 17 00:00:00 2001
From: Ross Lagerwall <ross.lagerwall@citrix.com>
Date: Fri, 11 Sep 2026 10:12:44 +0100
Subject: [PATCH] tools/libxl: Add support for Viridian stimer direct mode

Add support to libxl for using the stimer enlightenments in direct mode.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
---
 docs/man/xl.cfg.5.pod.in           | 5 +++++
 tools/golang/xenlight/types.gen.go | 1 +
 tools/include/libxl.h              | 6 ++++++
 tools/libs/light/libxl_types.idl   | 1 +
 tools/libs/light/libxl_x86.c       | 5 +++++
 5 files changed, 18 insertions(+)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index d34951edb9..30c401588f 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -2496,6 +2496,11 @@ ticks and hence enabling this group will ensure that ticks will be
 consistent with use of an enlightened time source (B<time_ref_count> or
 B<reference_tsc>).
 
+=item B<stimer_direct>
+
+This set is the same as the B<stimer> set but additionally supports
+using synthetic timers in direct mode.
+
 =item B<hcall_ipi>
 
 This set incorporates use of a hypercall for interprocessor interrupts.
diff --git a/tools/golang/xenlight/types.gen.go b/tools/golang/xenlight/types.gen.go
index 897100d9b6..3d3bcc1382 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -234,6 +234,7 @@ ViridianEnlightenmentHcallIpi ViridianEnlightenment = 9
 ViridianEnlightenmentExProcessorMasks ViridianEnlightenment = 10
 ViridianEnlightenmentNoVpLimit ViridianEnlightenment = 11
 ViridianEnlightenmentCpuHotplug ViridianEnlightenment = 12
+ViridianEnlightenmentStimerDirect ViridianEnlightenment = 13
 )
 
 type Hdtype int
diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index 617ce973b2..d294fb36bd 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -389,6 +389,12 @@
  */
 #define LIBXL_HAVE_VIRIDIAN_HCALL_IPI 1
 
+/*
+ * LIBXL_HAVE_VIRIDIAN_STIMER_DIRECT indicates that the 'stimer_direct' value
+ * is present in the viridian enlightenment enumeration.
+ */
+#define LIBXL_HAVE_VIRIDIAN_STIMER_DIRECT 1
+
 /*
  * LIBXL_HAVE_BUILDINFO_HVM_ACPI_LAPTOP_SLATE indicates that
  * libxl_domain_build_info has the u.hvm.acpi_laptop_slate field.
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index d3121ea277..27755801d1 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -260,6 +260,7 @@ libxl_viridian_enlightenment = Enumeration("viridian_enlightenment", [
     (10, "ex_processor_masks"),
     (11, "no_vp_limit"),
     (12, "cpu_hotplug"),
+    (13, "stimer_direct"),
     ])
 
 libxl_hdtype = Enumeration("hdtype", [
diff --git a/tools/libs/light/libxl_x86.c b/tools/libs/light/libxl_x86.c
index 60d4e8661c..9e8b48372d 100644
--- a/tools/libs/light/libxl_x86.c
+++ b/tools/libs/light/libxl_x86.c
@@ -389,6 +389,11 @@ static int hvm_set_viridian_features(libxl__gc *gc, uint32_t domid,
     if (libxl_bitmap_test(&enlightenments, LIBXL_VIRIDIAN_ENLIGHTENMENT_CPU_HOTPLUG))
         mask |= HVMPV_cpu_hotplug;
 
+    if (libxl_bitmap_test(&enlightenments,
+                          LIBXL_VIRIDIAN_ENLIGHTENMENT_STIMER_DIRECT))
+        mask |= HVMPV_time_ref_count | HVMPV_synic | HVMPV_stimer |
+                HVMPV_stimer_direct;
+
     if (mask != 0 &&
         xc_hvm_param_set(CTX->xch,
                          domid,