Re: [Qemu-devel] [Xen-devel] [XEN][RFC PATCH V2 12/17] xl: Add interface to handle qemu disaggregation

[Julien Grall <julien.grall@citrix.com>]

On 08/23/2012 02:30 PM, Ian Campbell wrote:
> On Wed, 2012-08-22 at 13:31 +0100, Julien Grall wrote:
>    
>> This patch modifies libxl interface for qemu disaggregation.
>>      
> I'd rather see the interfaces changes in the same patch as the
> implementation of the new interfaces.
>
>    
>> For the moment, due to some dependencies between devices, we
>> can't let the user choose which QEMU emulate a device.
>>
>> Moreoever this patch adds an "id" field to nic interface.
>> It will be used in config file to specify which QEMU handle
>> the network card.
>>      
> Is domid+devid not sufficient to identify which nic?
>    
Is the user can specify or find devid easily ?
I added "id" because, I would like that the user
can identify without any problem a network
interface.

>> A possible disaggregation is:
>>      - UI: Emulate graphic card, USB, keyboard, mouse, default devices
>>      (PIIX4, root bridge, ...)
>>      - IDE: Emulate disk
>>      - Serial: Emulate serial port
>>      - Audio: Emulate audio card
>>      - Net: Emulate one or more network cards, multiple QEMU can emulate
>>      different card. The emulated card is specified with its nic ID.
>>
>> Signed-off-by: Julien Grall<julien.grall@citrix.com>
>> ---
>>   tools/libxl/libxl.h         |    3 +++
>>   tools/libxl/libxl_types.idl |   15 +++++++++++++++
>>   2 files changed, 18 insertions(+), 0 deletions(-)
>>
>> diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
>> index c614d6f..71d4808 100644
>> --- a/tools/libxl/libxl.h
>> +++ b/tools/libxl/libxl.h
>> @@ -307,6 +307,7 @@ void libxl_cpuid_dispose(libxl_cpuid_policy_list *cpuid_list);
>>   #define LIBXL_PCI_FUNC_ALL (~0U)
>>
>>   typedef uint32_t libxl_domid;
>> +typedef uint32_t libxl_dmid;
>>
>>   /*
>>    * Formatting Enumerations.
>> @@ -478,12 +479,14 @@ typedef struct {
>>       libxl_domain_build_info b_info;
>>
>>       int num_disks, num_nics, num_pcidevs, num_vfbs, num_vkbs;
>> +    int num_dms;
>>
>>       libxl_device_disk *disks;
>>       libxl_device_nic *nics;
>>       libxl_device_pci *pcidevs;
>>       libxl_device_vfb *vfbs;
>>       libxl_device_vkb *vkbs;
>> +    libxl_dm *dms;
>>
>>       libxl_action_on_shutdown on_poweroff;
>>       libxl_action_on_shutdown on_reboot;
>> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
>> index daa8c79..36c802a 100644
>> --- a/tools/libxl/libxl_types.idl
>> +++ b/tools/libxl/libxl_types.idl
>> @@ -246,6 +246,20 @@ libxl_domain_sched_params = Struct("domain_sched_params",[
>>       ("extratime",    integer, {'init_val': 'LIBXL_DOMAIN_SCHED_PARAM_EXTRATIME_DEFAULT'}),
>>       ])
>>
>> +libxl_dm_cap = Enumeration("dm_cap", [
>> +    (1, "UI"), # Emulate all UI + default device
>>      
> What does "default device" equate too?
>    
The following devices:
    - i440fx
    - piix3
    - piix4
    - dma
    - xen apic
    - xen platform


>> +    (2, "IDE"), # Emulate IDE
>> +    (4, "SERIAL"), # Emulate Serial
>> +    (8, "AUDIO"), # Emulate audio
>> +    ])
>> +
>> +libxl_dm = Struct("dm", [
>> +    ("name",         string),
>> +    ("path",         string),
>> +    ("capabilities",   uint64),
>>      
> uint64 and not libxl_dm_cap?
>    
Will be fixed in the next patch version.

-- 
Julien