[RFC PATCH 7/8] xen/tools: add sve parameter in XL configuration

[Luca Fancellu <luca.fancellu@xxxxxxx>]

Add sve parameter in XL configuration to allow guests to use
SVE feature.

Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
---
 docs/man/xl.cfg.5.pod.in             | 11 +++++++++++
 tools/golang/xenlight/helpers.gen.go |  2 ++
 tools/golang/xenlight/types.gen.go   |  1 +
 tools/include/libxl.h                |  5 +++++
 tools/libs/light/libxl_arm.c         |  2 ++
 tools/libs/light/libxl_types.idl     |  1 +
 tools/xl/xl_parse.c                  | 10 ++++++++++
 7 files changed, 32 insertions(+)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index 024bceeb61b2..60412f7e32a0 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -2903,6 +2903,17 @@ Currently, only the "sbsa_uart" model is supported for 
ARM.
 
 =back
 
+=item B<sve="NUMBER">
+
+To enable SVE, user must specify a number different from zero, maximum 2048 and
+multiple of 128. That value will be the maximum number of SVE registers bits
+that the hypervisor will impose to this guest. If the platform has a lower bits
+value, then the lower value will be chosen.
+A value equal to zero is the default and it means this guest is not allowed to
+use SVE.
+
+=back
+
 =head3 x86
 
 =over 4
diff --git a/tools/golang/xenlight/helpers.gen.go 
b/tools/golang/xenlight/helpers.gen.go
index 3ac4938858f2..7f3b1e758b00 100644
--- a/tools/golang/xenlight/helpers.gen.go
+++ b/tools/golang/xenlight/helpers.gen.go
@@ -1117,6 +1117,7 @@ default:
 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.ArchArm.Sve = int(xc.arch_arm.sve)
 if err := x.ArchX86.MsrRelaxed.fromC(&xc.arch_x86.msr_relaxed);err != nil {
 return fmt.Errorf("converting field ArchX86.MsrRelaxed: %v", err)
 }
@@ -1602,6 +1603,7 @@ default:
 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.arch_arm.sve = C.int(x.Sve)
 if err := x.ArchX86.MsrRelaxed.toC(&xc.arch_x86.msr_relaxed); err != nil {
 return fmt.Errorf("converting field ArchX86.MsrRelaxed: %v", err)
 }
diff --git a/tools/golang/xenlight/types.gen.go 
b/tools/golang/xenlight/types.gen.go
index 16ce879e3fb7..ed144325682e 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -537,6 +537,7 @@ TypeUnion DomainBuildInfoTypeUnion
 ArchArm struct {
 GicVersion GicVersion
 Vuart VuartType
+Sve uint32
 }
 ArchX86 struct {
 MsrRelaxed Defbool
diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index d652895075a0..1057962e2e3f 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -278,6 +278,11 @@
  */
 #define LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE 1
 
+/*
+ * libxl_domain_build_info has the arch_arm.sve field.
+ */
+#define LIBXL_HAVE_BUILDINFO_ARCH_ARM_SVE 1
+
 /*
  * LIBXL_HAVE_SOFT_RESET indicates that libxl supports performing
  * 'soft reset' for domains and there is 'soft_reset' shutdown reason
diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index ddc7b2a15975..31f30e054bf4 100644
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -211,6 +211,8 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
         return ERROR_FAIL;
     }
 
+    config->arch.sve_vl_bits = d_config->b_info.arch_arm.sve;
+
     return 0;
 }
 
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 0cfad8508dbd..27e22523c7c2 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -663,6 +663,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
 
     ("arch_arm", Struct(None, [("gic_version", libxl_gic_version),
                                ("vuart", libxl_vuart_type),
+                               ("sve", uint32),
                               ])),
     ("arch_x86", Struct(None, [("msr_relaxed", libxl_defbool),
                               ])),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 853e9f357a1a..49b2f28807e5 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -2828,6 +2828,16 @@ skip_usbdev:
         }
     }
 
+    if (!xlu_cfg_get_long (config, "sve", &l, 0)) {
+        if (((l % 128) != 0) || (l > 2048)) {
+            fprintf(stderr,
+                    "Invalid sve value: %ld. Needs to be <= 2048 and multiple"
+                    " of 128\n", l);
+            exit(-ERROR_FAIL);
+        }
+        b_info->arch_arm.sve = l;
+    }
+
     parse_vkb_list(config, d_config);
 
     d_config->virtios = NULL;
-- 
2.17.1