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

[Julien Grall]

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<address@hidden>
> > ---
> >   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