hvm_xs_strings.h specifies xenstore entries which can be used to set or
override smbios strings.  hvmloader has support for reading them, but
xl/libxl support is not wired up.

Allow specifying the strings with the new xl.cfg option:
smbios=["bios_vendor=Xen Project","system_version=1.0"]

In terms of strings, the SMBIOS specification 3.5 says:
https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.5.0.pdf
"""
Strings must be encoded as UTF-8 with no byte order mark (BOM). For
compatibility with older SMBIOS parsers, US-ASCII characters should be
used.  NOTE There is no limit on the length of each individual text
string. However, the length of the entire structure table (including all
strings) must be reported in the Structure Table Length field of the
32-bit Structure Table Entry Point (see 5.2.1) and/or the Structure
Table Maximum Size field of the 64-bit Structure Table Entry Point (see
5.2.2).
"""

The strings aren't checked for utf-8 or length.  hvmloader has a sanity
check on the overall length.

The libxl_smbios_type enum starts at 1 since otherwise the 0th key is
not printed in the json output.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
---
v3
Disallow empty value strings
xstrdup listitem before modifying
Handle option=foo=bar -> option foo=bar
Fix compilation - remove stray }
Remove log message newline
Add multiline comment star
Rename variable v to key

v2:
Update s/_/-/ comment
Update debug print to xs_path = "value"
Error on xlu_cfg_get_listitem failure
Use EXIT_FAILURE consistently
free parsed strings
Move break to new line

The rendered man page and html don't have a newline at the end of the
new section.
"""
           battery_device_name=STRING
       ms_vm_genid="OPTION"
"""

however the txt format is correct:
"""
        battery_device_name=STRING

    ms_vm_genid="OPTION"
"""

I'm at a loss as to why this is happening.
---
 docs/man/xl.cfg.5.pod.in             | 45 +++++++++++++++++++++
 tools/golang/xenlight/helpers.gen.go | 51 ++++++++++++++++++++++++
 tools/golang/xenlight/types.gen.go   | 27 +++++++++++++
 tools/include/libxl.h                |  5 +++
 tools/libs/light/libxl_dom.c         | 21 ++++++++++
 tools/libs/light/libxl_types.idl     | 26 +++++++++++++
 tools/xl/xl_parse.c                  | 58 +++++++++++++++++++++++++++-
 7 files changed, 232 insertions(+), 1 deletion(-)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index 024bceeb61..bc4386ee96 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -2079,6 +2079,51 @@ number of vendor defined SMBIOS structures (type 128 - 255). Since SMBIOS
 structures do not present their overall size, each entry in the file must be
 preceded by a 32b integer indicating the size of the following structure.
 
+=item B<smbios=[ "SMBIOS_SPEC_STRING", "SMBIOS_SPEC_STRING", ...]>
+
+Specifies the SMBIOS values to be provided to the guest.  These set or
+override specific entries in the tables provided to the guest.
+
+Each B<SMBIOS_SPEC_STRING> is a C<KEY=VALUE> string from the following list:
+
+=over 4
+
+=item B<bios_vendor=STRING>
+
+=item B<bios_version=STRING>
+
+=item B<system_manufacturer=STRING>
+
+=item B<system_product_name=STRING>
+
+=item B<system_version=STRING>
+
+=item B<system_serial_number=STRING>
+
+=item B<baseboard_manufacturer=STRING>
+
+=item B<baseboard_product_name=STRING>
+
+=item B<baseboard_version=STRING>
+
+=item B<baseboard_serial_number=STRING>
+
+=item B<baseboard_asset_tag=STRING>
+
+=item B<baseboard_location_in_chassis=STRING>
+
+=item B<enclosure_manufacturer=STRING>
+
+=item B<enclosure_serial_number=STRING>
+
+=item B<enclosure_asset_tag=STRING>
+
+=item B<battery_manufacturer=STRING>
+
+=item B<battery_device_name=STRING>
+
+=back
+
 =item B<ms_vm_genid="OPTION">
 
 Provide a VM generation ID to the guest.
diff --git a/tools/golang/xenlight/helpers.gen.go b/tools/golang/xenlight/helpers.gen.go
index 3ac4938858..0a203d2232 100644
--- a/tools/golang/xenlight/helpers.gen.go
+++ b/tools/golang/xenlight/helpers.gen.go
@@ -589,6 +589,38 @@ xc.build_id = C.CString(x.BuildId)}
  return nil
  }
 
+// NewSmbios returns an instance of Smbios initialized with defaults.
+func NewSmbios() (*Smbios, error) {
+var (
+x Smbios
+xc C.libxl_smbios)
+
+C.libxl_smbios_init(&xc)
+defer C.libxl_smbios_dispose(&xc)
+
+if err := x.fromC(&xc); err != nil {
+return nil, err }
+
+return &x, nil}
+
+func (x *Smbios) fromC(xc *C.libxl_smbios) error {
+ x.Key = SmbiosType(xc.key)
+x.Value = C.GoString(xc.value)
+
+ return nil}
+
+func (x *Smbios) toC(xc *C.libxl_smbios) (err error){defer func(){
+if err != nil{
+C.libxl_smbios_dispose(xc)}
+}()
+
+xc.key = C.libxl_smbios_type(x.Key)
+if x.Value != "" {
+xc.value = C.CString(x.Value)}
+
+ return nil
+ }
+
 // NewDomainCreateInfo returns an instance of DomainCreateInfo initialized with defaults.
 func NewDomainCreateInfo() (*DomainCreateInfo, error) {
 var (
@@ -1183,6 +1215,15 @@ return fmt.Errorf("converting field Altp2M: %v", err)
 }
 x.SystemFirmware = C.GoString(tmp.system_firmware)
 x.SmbiosFirmware = C.GoString(tmp.smbios_firmware)
+x.Smbios = nil
+if n := int(tmp.num_smbios); n > 0 {
+cSmbios := (*[1<<28]C.libxl_smbios)(unsafe.Pointer(tmp.smbios))[:n:n]
+x.Smbios = make([]Smbios, n)
+for i, v := range cSmbios {
+if err := x.Smbios[i].fromC(&v); err != nil {
+return fmt.Errorf("converting field Smbios: %v", err) }
+}
+}
 x.AcpiFirmware = C.GoString(tmp.acpi_firmware)
 x.Hdtype = Hdtype(tmp.hdtype)
 if err := x.Nographic.fromC(&tmp.nographic);err != nil {
@@ -1495,6 +1536,16 @@ if tmp.SystemFirmware != "" {
 hvm.system_firmware = C.CString(tmp.SystemFirmware)}
 if tmp.SmbiosFirmware != "" {
 hvm.smbios_firmware = C.CString(tmp.SmbiosFirmware)}
+if numSmbios := len(tmp.Smbios); numSmbios > 0 {
+hvm.smbios = (*C.libxl_smbios)(C.malloc(C.ulong(numSmbios)*C.sizeof_libxl_smbios))
+hvm.num_smbios = C.int(numSmbios)
+cSmbios := (*[1<<28]C.libxl_smbios)(unsafe.Pointer(hvm.smbios))[:numSmbios:numSmbios]
+for i,v := range tmp.Smbios {
+if err := v.toC(&cSmbios[i]); err != nil {
+return fmt.Errorf("converting field Smbios: %v", err)
+}
+}
+}
 if tmp.AcpiFirmware != "" {
 hvm.acpi_firmware = C.CString(tmp.AcpiFirmware)}
 hvm.hdtype = C.libxl_hdtype(tmp.Hdtype)
diff --git a/tools/golang/xenlight/types.gen.go b/tools/golang/xenlight/types.gen.go
index 16ce879e3f..2d8bc7654a 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -392,6 +392,32 @@ Commandline string
 BuildId string
 }
 
+type SmbiosType int
+const(
+SmbiosTypeBiosVendor SmbiosType = 1
+SmbiosTypeBiosVersion SmbiosType = 2
+SmbiosTypeSystemManufacturer SmbiosType = 3
+SmbiosTypeSystemProductName SmbiosType = 4
+SmbiosTypeSystemVersion SmbiosType = 5
+SmbiosTypeSystemSerialNumber SmbiosType = 6
+SmbiosTypeBaseboardManufacturer SmbiosType = 7
+SmbiosTypeBaseboardProductName SmbiosType = 8
+SmbiosTypeBaseboardVersion SmbiosType = 9
+SmbiosTypeBaseboardSerialNumber SmbiosType = 10
+SmbiosTypeBaseboardAssetTag SmbiosType = 11
+SmbiosTypeBaseboardLocationInChassis SmbiosType = 12
+SmbiosTypeEnclosureManufacturer SmbiosType = 13
+SmbiosTypeEnclosureSerialNumber SmbiosType = 14
+SmbiosTypeEnclosureAssetTag SmbiosType = 15
+SmbiosTypeBatteryManufacturer SmbiosType = 16
+SmbiosTypeBatteryDeviceName SmbiosType = 17
+)
+
+type Smbios struct {
+Key SmbiosType
+Value string
+}
+
 type DomainCreateInfo struct {
 Type DomainType
 Hap Defbool
@@ -572,6 +598,7 @@ NestedHvm Defbool
 Altp2M Defbool
 SystemFirmware string
 SmbiosFirmware string
+Smbios []Smbios
 AcpiFirmware string
 Hdtype Hdtype
 Nographic Defbool
diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index d652895075..5c65222f1e 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -174,6 +174,11 @@
  */
 #define LIBXL_HAVE_BUILDINFO_HVM_MS_VM_GENID 1
 
+/*
+ * libxl_domain_build_info has the u.hvm.smbios field.
+ */
+#define LIBXL_HAVE_BUILDINFO_HVM_SMBIOS 1
+
 /*
  * LIBXL_HAVE_VCPUINFO_SOFT_AFFINITY indicates that a 'cpumap_soft'
  * field (of libxl_bitmap type) is present in libxl_vcpuinfo,
diff --git a/tools/libs/light/libxl_dom.c b/tools/libs/light/libxl_dom.c
index f6311eea6e..5433301f70 100644
--- a/tools/libs/light/libxl_dom.c
+++ b/tools/libs/light/libxl_dom.c
@@ -773,6 +773,27 @@ static int hvm_build_set_xs_values(libxl__gc *gc,
             goto err;
     }
 
+    for (int i = 0; i < info->u.hvm.num_smbios; i++) {
+        char *p;
+        path = GCSPRINTF("/local/domain/%d/"HVM_XS_BIOS_STRINGS"/%s", domid,
+                   libxl_smbios_type_to_string(info->u.hvm.smbios[i].key));
+
+        /* Convert libxl_smbios_type string to xenstore path that hvmloader
+         * will use, as defined by HVM_XS_*. That is convert the '_' to '-'. */
+        p = strrchr(path, '/');
+        for ( ; *p; p++) {
+            if (*p == '_')
+                *p = '-';
+        }
+
+        LOGD(DEBUG, domid, "Writing %s = \"%s\"", path,
+             info->u.hvm.smbios[i].value);
+        ret = libxl__xs_printf(gc, XBT_NULL, path, "%s",
+                               info->u.hvm.smbios[i].value);
+        if (ret)
+            goto err;
+    }
+
     /* Only one module can be passed. PVHv2 guests do not support this. */
     if (dom->acpi_modules[0].guest_addr_out && 
         info->type == LIBXL_DOMAIN_TYPE_HVM) {
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 0cfad8508d..df4dd36697 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -423,6 +423,31 @@ libxl_version_info = Struct("version_info", [
     ("build_id",          string),
     ], dir=DIR_OUT)
 
+libxl_smbios_type = Enumeration("smbios_type", [
+    (1,  "bios_vendor"),
+    (2,  "bios_version"),
+    (3,  "system_manufacturer"),
+    (4,  "system_product_name"),
+    (5,  "system_version"),
+    (6,  "system_serial_number"),
+    (7,  "baseboard_manufacturer"),
+    (8,  "baseboard_product_name"),
+    (9,  "baseboard_version"),
+    (10, "baseboard_serial_number"),
+    (11, "baseboard_asset_tag"),
+    (12, "baseboard_location_in_chassis"),
+    (13, "enclosure_manufacturer"),
+    (14, "enclosure_serial_number"),
+    (15, "enclosure_asset_tag"),
+    (16, "battery_manufacturer"),
+    (17, "battery_device_name"),
+    ])
+
+libxl_smbios = Struct("smbios", [
+    ("key",          libxl_smbios_type),
+    ("value",        string),
+    ], dir=DIR_IN)
+
 libxl_domain_create_info = Struct("domain_create_info",[
     ("type",         libxl_domain_type),
     ("hap",          libxl_defbool),
@@ -609,6 +634,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
                                        ("altp2m",           libxl_defbool),
                                        ("system_firmware",  string),
                                        ("smbios_firmware",  string),
+                                       ("smbios",           Array(libxl_smbios, "num_smbios")),
                                        ("acpi_firmware",    string),
                                        ("hdtype",           libxl_hdtype),
                                        ("nographic",        libxl_defbool),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 853e9f357a..ba219024b6 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -1297,8 +1297,9 @@ void parse_config_data(const char *config_source,
     XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms,
                    *usbctrls, *usbdevs, *p9devs, *vdispls, *pvcallsifs_devs;
     XLU_ConfigList *channels, *ioports, *irqs, *iomem, *viridian, *dtdevs,
-                   *mca_caps;
+                   *mca_caps, *smbios;
     int num_ioports, num_irqs, num_iomem, num_cpus, num_viridian, num_mca_caps;
+    int num_smbios;
     int pci_power_mgmt = 0;
     int pci_msitranslate = 0;
     int pci_permissive = 0;
@@ -1860,6 +1861,61 @@ void parse_config_data(const char *config_source,
         xlu_cfg_replace_string(config, "acpi_firmware",
                                &b_info->u.hvm.acpi_firmware, 0);
 
+        switch (xlu_cfg_get_list(config, "smbios", &smbios, &num_smbios, 0))
+        {
+        case 0: /* Success */
+            b_info->u.hvm.num_smbios = num_smbios;
+            b_info->u.hvm.smbios = xcalloc(num_smbios, sizeof(libxl_smbios));
+            for (i = 0; i < num_smbios; i++) {
+                libxl_smbios_type type;
+                char *option;
+                char *value;
+
+                buf = xlu_cfg_get_listitem(smbios, i);
+                if (!buf) {
+                    fprintf(stderr,
+                            "xl: Unable to get element #%d in smbios list\n",
+                            i);
+                    exit(EXIT_FAILURE);
+                }
+
+                option = xstrdup(buf);
+                value = strchr(option, '=');
+                if (value == NULL) {
+                    fprintf(stderr, "xl: failed to split \"%s\" at '='\n",
+                            option);
+                    exit(EXIT_FAILURE);
+                }
+
+                *value = '\0';
+                value++;
+
+                if (*value == '\0') {
+                    fprintf(stderr,
+                            "xl: empty value not allowed for smbios \"%s=\"\n",
+                            option);
+                    exit(EXIT_FAILURE);
+                }
+
+                e = libxl_smbios_type_from_string(option, &type);
+                if (e) {
+                    fprintf(stderr, "xl: unknown smbios type '%s'\n", option);
+                    exit(EXIT_FAILURE);
+                }
+
+                b_info->u.hvm.smbios[i].key = type;
+                b_info->u.hvm.smbios[i].value = xstrdup(value);
+
+                free(option);
+            }
+            break;
+        case ESRCH: /* Option not present */
+            break;
+        default:
+            fprintf(stderr,"xl: Unable to parse smbios options.\n");
+            exit(EXIT_FAILURE);
+        }
+
         if (!xlu_cfg_get_string(config, "ms_vm_genid", &buf, 0)) {
             if (!strcmp(buf, "generate")) {
                 e = libxl_ms_vm_genid_generate(ctx, &b_info->u.hvm.ms_vm_genid);
-- 
2.39.2

On Mon, Mar 06, 2023 at 03:40:23PM -0500, Jason Andryuk wrote:
> hvm_xs_strings.h specifies xenstore entries which can be used to set or
> override smbios strings.  hvmloader has support for reading them, but
> xl/libxl support is not wired up.
> 
> Allow specifying the strings with the new xl.cfg option:
> smbios=["bios_vendor=Xen Project","system_version=1.0"]
> 
> In terms of strings, the SMBIOS specification 3.5 says:
> https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.5.0.pdf
> """
> Strings must be encoded as UTF-8 with no byte order mark (BOM). For
> compatibility with older SMBIOS parsers, US-ASCII characters should be
> used.  NOTE There is no limit on the length of each individual text
> string. However, the length of the entire structure table (including all
> strings) must be reported in the Structure Table Length field of the
> 32-bit Structure Table Entry Point (see 5.2.1) and/or the Structure
> Table Maximum Size field of the 64-bit Structure Table Entry Point (see
> 5.2.2).
> """
> 
> The strings aren't checked for utf-8 or length.  hvmloader has a sanity
> check on the overall length.
> 
> The libxl_smbios_type enum starts at 1 since otherwise the 0th key is
> not printed in the json output.
> 
> Signed-off-by: Jason Andryuk <jandryuk@gmail.com>

Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

Thanks,

-- 
Anthony PERARD