xen/tools: add sve parameter in XL configuration

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

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

docs/man/xl.cfg.5.pod.in

@@ -2955,6 +2955,22 @@ Currently, only the "sbsa_uart" model is supported for ARM.
 
 =back
 
+=item B<sve="vl">
+
+The `sve` parameter enables Arm Scalable Vector Extension (SVE) usage for the
+guest and sets the maximum SVE vector length, the option is applicable only to
+AArch64 guests.
+A value equal to "disabled" disables the feature, this is the default value.
+Allowed values are "disabled", "128", "256", "384", "512", "640", "768", "896",
+"1024", "1152", "1280", "1408", "1536", "1664", "1792", "1920", "2048", "hw".
+Specifying "hw" means that the maximum vector length supported by the platform
+will be used.
+Please be aware that if a specific vector length is passed and its value is
+above the maximum vector length supported by the platform, an error will be
+raised.
+
+=back
+
 =head3 x86
 
 =over 4

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.SveVl = SveType(xc.arch_arm.sve_vl)
 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_vl = C.libxl_sve_type(x.ArchArm.SveVl)
 if err := x.ArchX86.MsrRelaxed.toC(&xc.arch_x86.msr_relaxed); err != nil {
 return fmt.Errorf("converting field ArchX86.MsrRelaxed: %v", err)
 }

tools/golang/xenlight/types.gen.go

@@ -490,6 +490,28 @@ TeeTypeNone TeeType = 0
 TeeTypeOptee TeeType = 1
 )
 
+type SveType int
+const(
+SveTypeHw SveType = -1
+SveTypeDisabled SveType = 0
+SveType128 SveType = 128
+SveType256 SveType = 256
+SveType384 SveType = 384
+SveType512 SveType = 512
+SveType640 SveType = 640
+SveType768 SveType = 768
+SveType896 SveType = 896
+SveType1024 SveType = 1024
+SveType1152 SveType = 1152
+SveType1280 SveType = 1280
+SveType1408 SveType = 1408
+SveType1536 SveType = 1536
+SveType1664 SveType = 1664
+SveType1792 SveType = 1792
+SveType1920 SveType = 1920
+SveType2048 SveType = 2048
+)
+
 type RdmReserve struct {
 Strategy RdmReserveStrategy
 Policy RdmReservePolicy
@@ -564,6 +586,7 @@ TypeUnion DomainBuildInfoTypeUnion
 ArchArm struct {
 GicVersion GicVersion
 Vuart VuartType
+SveVl SveType
 }
 ArchX86 struct {
 MsrRelaxed Defbool

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_vl field.
+ */
+#define LIBXL_HAVE_BUILDINFO_ARCH_ARM_SVE_VL 1
+
 /*
  * LIBXL_HAVE_SOFT_RESET indicates that libxl supports performing
  * 'soft reset' for domains and there is 'soft_reset' shutdown reason

tools/libs/light/libxl_arm.c

@@ -3,6 +3,8 @@
 #include "libxl_libfdt_compat.h"
 #include "libxl_arm.h"
 
+#include <xen-tools/arm-arch-capabilities.h>
+
 #include <stdbool.h>
 #include <libfdt.h>
 #include <assert.h>
@@ -211,6 +213,12 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
         return ERROR_FAIL;
     }
 
+    /* Parameter is sanitised in libxl__arch_domain_build_info_setdefault */
+    if (d_config->b_info.arch_arm.sve_vl) {
+        /* Vector length is divided by 128 in struct xen_domctl_createdomain */
+        config->arch.sve_vl = d_config->b_info.arch_arm.sve_vl / 128U;
+    }
+
     return 0;
 }
 
@@ -1685,6 +1693,31 @@ int libxl__arch_domain_build_info_setdefault(libxl__gc *gc,
     /* ACPI is disabled by default */
     libxl_defbool_setdefault(&b_info->acpi, false);
 
+    /* Sanitise SVE parameter */
+    if (b_info->arch_arm.sve_vl) {
+        unsigned int max_sve_vl =
+            arch_capabilities_arm_sve(physinfo->arch_capabilities);
+
+        if (!max_sve_vl) {
+            LOG(ERROR, "SVE is unsupported on this machine.");
+            return ERROR_FAIL;
+        }
+
+        if (LIBXL_SVE_TYPE_HW == b_info->arch_arm.sve_vl) {
+            b_info->arch_arm.sve_vl = max_sve_vl;
+        } else if (b_info->arch_arm.sve_vl > max_sve_vl) {
+            LOG(ERROR,
+                "Invalid sve value: %d. Platform supports up to %u bits",
+                b_info->arch_arm.sve_vl, max_sve_vl);
+            return ERROR_FAIL;
+        } else if (b_info->arch_arm.sve_vl % 128) {
+            LOG(ERROR,
+                "Invalid sve value: %d. It must be multiple of 128",
+                b_info->arch_arm.sve_vl);
+            return ERROR_FAIL;
+        }
+    }
+
     if (b_info->type != LIBXL_DOMAIN_TYPE_PV)
         return 0;
 

tools/libs/light/libxl_types.idl

@@ -523,6 +523,27 @@ libxl_tee_type = Enumeration("tee_type", [
     (1, "optee")
     ], init_val = "LIBXL_TEE_TYPE_NONE")
 
+libxl_sve_type = Enumeration("sve_type", [
+    (-1, "hw"),
+    (0, "disabled"),
+    (128, "128"),
+    (256, "256"),
+    (384, "384"),
+    (512, "512"),
+    (640, "640"),
+    (768, "768"),
+    (896, "896"),
+    (1024, "1024"),
+    (1152, "1152"),
+    (1280, "1280"),
+    (1408, "1408"),
+    (1536, "1536"),
+    (1664, "1664"),
+    (1792, "1792"),
+    (1920, "1920"),
+    (2048, "2048")
+    ], init_val = "LIBXL_SVE_TYPE_DISABLED")
+
 libxl_rdm_reserve = Struct("rdm_reserve", [
     ("strategy",    libxl_rdm_reserve_strategy),
     ("policy",      libxl_rdm_reserve_policy),
@@ -690,6 +711,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
 
     ("arch_arm", Struct(None, [("gic_version", libxl_gic_version),
                                ("vuart", libxl_vuart_type),
+                               ("sve_vl", libxl_sve_type),
                               ])),
     ("arch_x86", Struct(None, [("msr_relaxed", libxl_defbool),
                               ])),

tools/xl/xl_parse.c

@@ -2887,6 +2887,14 @@ skip_usbdev:
         }
     }
 
+    if (!xlu_cfg_get_string (config, "sve", &buf, 1)) {
+        e = libxl_sve_type_from_string(buf, &b_info->arch_arm.sve_vl);
+        if (e) {
+            fprintf(stderr, "Unknown sve \"%s\" specified\n", buf);
+            exit(EXIT_FAILURE);
+        }
+    }
+
     parse_vkb_list(config, d_config);
 
     d_config->virtios = NULL;