Re: [PATCH 1/5] hw/smbios: support loading OEM strings values from a file

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Sep 08, 2020 at 08:24:35PM +0200, Philippe Mathieu-Daudé wrote:
> Hi Daniel,
> 
> On 9/8/20 6:54 PM, Daniel P. Berrangé wrote:
> > Some applications want to pass quite large values for the OEM strings
> > entries. Rather than having huge strings on the command line, it would
> > be better to load them from a file, as supported with -fw_cfg.
> > 
> > This introduces the "valuefile" parameter allowing for:
> > 
> >   $ echo -n "thisthing" > mydata.txt
> >   $ qemu-system-x86_64 \
> >     -smbios type=11,value=something \
> >     -smbios type=11,valuefile=mydata.txt \
> >     -smbios type=11,value=somemore \
> >     ...other args...
> > 
> > Now in the guest
> > 
> > $ dmidecide -t 11
> > Getting SMBIOS data from sysfs.
> > SMBIOS 2.8 present.
> > 
> > Handle 0x0E00, DMI type 11, 5 bytes
> > OEM Strings
> > 	String 1: something
> > 	String 2: thisthing
> > 	String 3: somemore
> > 
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> > ---
> >  hw/smbios/smbios.c | 72 +++++++++++++++++++++++++++++++++++++---------
> >  1 file changed, 59 insertions(+), 13 deletions(-)
> > 
> > diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
> > index 7cc950b41c..8450fad285 100644
> > --- a/hw/smbios/smbios.c
> > +++ b/hw/smbios/smbios.c
> > @@ -110,7 +110,7 @@ static struct {
> >  
> >  static struct {
> >      size_t nvalues;
> > -    const char **values;
> > +    char **values;
> >  } type11;
> >  
> >  static struct {
> > @@ -314,6 +314,11 @@ static const QemuOptDesc qemu_smbios_type11_opts[] = {
> >          .type = QEMU_OPT_STRING,
> >          .help = "OEM string data",
> >      },
> > +    {
> > +        .name = "path",
> > +        .type = QEMU_OPT_STRING,
> > +        .help = "OEM string data from file",
> > +    },
> >  };
> >  
> >  static const QemuOptDesc qemu_smbios_type17_opts[] = {
> > @@ -641,6 +646,8 @@ static void smbios_build_type_11_table(void)
> >  
> >      for (i = 0; i < type11.nvalues; i++) {
> >          SMBIOS_TABLE_SET_STR_LIST(11, type11.values[i]);
> > +        g_free(type11.values[i]);
> > +        type11.values[i] = NULL;
> >      }
> >  
> >      SMBIOS_BUILD_TABLE_POST;
> > @@ -940,9 +947,8 @@ static void save_opt(const char **dest, QemuOpts *opts, const char *name)
> >  
> >  
> >  struct opt_list {
> > -    const char *name;
> >      size_t *ndest;
> > -    const char ***dest;
> > +    char ***dest;
> >  };
> >  
> >  static int save_opt_one(void *opaque,
> > @@ -951,23 +957,61 @@ static int save_opt_one(void *opaque,
> >  {
> >      struct opt_list *opt = opaque;
> >  
> > -    if (!g_str_equal(name, opt->name)) {
> > -        return 0;
> > +    if (g_str_equal(name, "path")) {
> > +        g_autoptr(GByteArray) data = g_byte_array_new();
> > +        g_autofree char *buf = g_new(char, 4096);
> > +        ssize_t ret;
> > +        int fd = qemu_open(value, O_RDONLY);
> 
> While not use g_file_get_contents()?

qemu_open lets mgmt apps pass in pre-opened FDs using /dev/fdset/NN
syntax.


Regards,
Daniel
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