[libvirt] [PATCH 2/2] libxl: allow an <emulator> to be selected in the domain config XML

[Jim Fehlig]

Jim Fehlig wrote:
> David Scott wrote:
>   
>> We cross-check the given path against the capabilties, and translate
>> it into a libxl_device_model_version.
>>
>> Signed-off-by: David Scott <dave.scott at eu.citrix.com>
>> ---
>>  src/libxl/libxl_conf.c |   41 +++++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 41 insertions(+), 0 deletions(-)
>>
>> diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
>> index 472d116..868d0cf 100644
>> --- a/src/libxl/libxl_conf.c
>> +++ b/src/libxl/libxl_conf.c
>> @@ -75,6 +75,11 @@ static const char* emulator_lib32_path [] = {
>>      EMULATOR_LIB32 EMULATOR_UPSTREAM,
>>  };
>>  
>> +static const libxl_device_model_version emulator_to_device_model [] = {
>> +    LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL,
>> +    LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN,
>> +};
>> +
>>  struct guest_arch {
>>      virArch arch;
>>      int bits;
>> @@ -833,6 +838,38 @@ libxlMakeCapabilities(libxl_ctx *ctx)
>>  }
>>  
>>  int
>> +libxlMakeEmulator(virDomainDefPtr def, libxl_domain_config *d_config)
>> +{
>> +    virArch hostarch;
>> +    const char *path;
>> +    int i;
>> +
>> +    /* No explicit override means use the default */
>> +    if (!def->emulator) {
>> +        return 0;
>> +    }
>> +
>> +    hostarch = virArchFromHost();
>> +
>> +    for (i = 0; i < emulator_last; ++i) {
>> +       path = ((hostarch == VIR_ARCH_X86_64) ?
>> +               emulator_lib64_path[i] :
>> +               emulator_lib32_path[i]);
>> +       if (STREQ(path, def->emulator)) {
>>   
>>     
>
> I thought there was a virCapabilitiesSupportsGuestEmulator() or similar,
> but I don't see it in src/conf/capabilities.c.  I think it makes sense
> to add such a function to the capabilities and then just call it here,
> passing the requested emulator.  Perhaps other libvirt developers can
> comment on the usefulness of virCapabilitiesSupportGuestEmulator().
>   

Daniel already clarified this, so no need to do even more work David :).

As mentioned in my other response [1], your original patch (with a check
to verify the requested emulator exists) should be sufficient.

Regards,
Jim

[1] https://www.redhat.com/archives/libvir-list/2013-April/msg02087.html