[PATCH v3 09/10] xen/tools: add sve parameter in XL configuration

[Luca Fancellu <luca.fancellu@arm.com>]

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

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>
---
Changes from v2:
 - domain configuration field name has changed to sve_vl,
   also its value now is VL/128.
 - Add Ack-by George for the Golang bits
Changes from v1:
 - updated to use arch_capabilities field for vector length
Changes from RFC:
 - changed libxl_types.idl sve field to uint16
 - now toolstack uses info from physinfo to check against the
   sve XL value
 - Changed documentation
---
 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                  | 26 ++++++++++++++++++++++++--
 7 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index 10f37990be57..adf48fe8ac1d 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -2952,6 +2952,17 @@ 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
+supported bits value, then the domain creation will fail.
+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 35397be2f9e2..72a3a12a6065 100644
--- a/tools/golang/xenlight/helpers.gen.go
+++ b/tools/golang/xenlight/helpers.gen.go
@@ -1149,6 +1149,7 @@ 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 = uint16(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)
 }
@@ -1653,6 +1654,7 @@ 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.uint16_t(x.ArchArm.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 3d968a496744..3dc292b5f1be 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -564,6 +564,7 @@ TypeUnion DomainBuildInfoTypeUnion
 ArchArm struct {
 GicVersion GicVersion
 Vuart VuartType
+Sve uint16
 }
 ArchX86 struct {
 MsrRelaxed Defbool
diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index 5c65222f1ecb..c9719d2d785a 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -283,6 +283,11 @@
  */
 #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..16a49031fd51 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 = 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 fd31dacf7d5a..ef4a8358e54e 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -690,6 +690,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
 
     ("arch_arm", Struct(None, [("gic_version", libxl_gic_version),
                                ("vuart", libxl_vuart_type),
+                               ("sve", uint16),
                               ])),
     ("arch_x86", Struct(None, [("msr_relaxed", libxl_defbool),
                               ])),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index e344d4fda32e..3962ec6ec8cd 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -12,6 +12,7 @@
  * GNU Lesser General Public License for more details.
  */
 
+#include <arm-arch-capabilities.h>
 #include <ctype.h>
 #include <inttypes.h>
 #include <limits.h>
@@ -1317,8 +1318,6 @@ void parse_config_data(const char *config_source,
         exit(EXIT_FAILURE);
     }
 
-    libxl_physinfo_dispose(&physinfo);
-
     config= xlu_cfg_init(stderr, config_source);
     if (!config) {
         fprintf(stderr, "Failed to allocate for configuration\n");
@@ -2897,6 +2896,29 @@ skip_usbdev:
         }
     }
 
+    if (!xlu_cfg_get_long (config, "sve", &l, 0)) {
+        unsigned int arm_sve_vl =
+            arch_capabilities_arm_sve(physinfo.arch_capabilities);
+        if (!arm_sve_vl) {
+            fprintf(stderr, "SVE is not supported by the platform\n");
+            exit(-ERROR_FAIL);
+        } else 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);
+        } else if (l > arm_sve_vl) {
+            fprintf(stderr,
+                    "Invalid sve value: %ld. Platform supports up to %u bits\n",
+                    l, arm_sve_vl);
+            exit(-ERROR_FAIL);
+        }
+        /* Vector length is divided by 128 in domain configuration struct */
+        b_info->arch_arm.sve = l / 128U;
+    }
+
+    libxl_physinfo_dispose(&physinfo);
+
     parse_vkb_list(config, d_config);
 
     d_config->virtios = NULL;
-- 
2.34.1