Re: [Qemu-devel] [PATCHv2 1/1] Add usb option in machine options to enable/disable usb

[Markus Armbruster <armbru@redhat.com>]

Li Zhang <zhlcindy@gmail.com> writes:

> On Fri, Jun 15, 2012 at 8:04 PM, Markus Armbruster <armbru@redhat.com> wrote:
>> Li Zhang <zhlcindy@linux.vnet.ibm.com> writes:
>>
>>> For pseries machine, it needs to enable usb to add
>>> keyboard or usb mouse. -usb option won't be used in
>>> the future, and machine options is a better way to
>>> enable usb.
>>>
>>> So this patch is to add usb option to machine options
>>> (-machine type=psereis,usb=on/off)to enable/disable
>>> usb controller.
>>>
>>> In this patch, usb_on is an global option which can
>>> be checked by machines.
>>> For example, on pseries, it will check if usb_on is 1,
>>> if it is 1, it will create one usb ohci controller.
>>> As the following:
>>> if (usb_on == 1) {
>>>      pci_create_simple(bus, -1, "pci-ohci");
>>> }
>>>
>>> In this patch, usb is on by default. So, for -nodefault,
>>> usb should be set off in the command line as the following:
>>>  -machine type=pseries,usb=off.
>>>
>>> Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
>>>
>>> ---
>>>  hw/spapr.c |    5 +++++
>>>  sysemu.h   |    1 +
>>>  vl.c       |   17 +++++++++++++++++
>>>  3 files changed, 23 insertions(+)
>>>
>>> diff --git a/hw/spapr.c b/hw/spapr.c
>>> index d0bddbc..1feb739 100644
>>> --- a/hw/spapr.c
>>> +++ b/hw/spapr.c
>>> @@ -661,6 +661,11 @@ static void ppc_spapr_init(ram_addr_t ram_size,
>>>          spapr_vscsi_create(spapr->vio_bus);
>>>      }
>>>
>>> +    if (usb_on == 1) {
>>> +        pci_create_simple(QLIST_FIRST(&spapr->phbs)->host_state.bus,
>>> +                          -1, "pci-ohci");
>>> +    }
>>> +
>>>      if (rma_size < (MIN_RMA_SLOF << 20)) {
>>>          fprintf(stderr, "qemu: pSeries SLOF firmware requires >= "
>>>                  "%ldM guest RMA (Real Mode Area memory)\n", MIN_RMA_SLOF);
>>> diff --git a/sysemu.h b/sysemu.h
>>> index bc2c788..08134ae 100644
>>> --- a/sysemu.h
>>> +++ b/sysemu.h
>>> @@ -109,6 +109,7 @@ extern int vga_interface_type;
>>>  #define vmsvga_enabled (vga_interface_type == VGA_VMWARE)
>>>  #define qxl_enabled (vga_interface_type == VGA_QXL)
>>>
>>> +extern int usb_on;
>>>  extern int graphic_width;
>>>  extern int graphic_height;
>>>  extern int graphic_depth;
>>> diff --git a/vl.c b/vl.c
>>> index 204d85b..b200203 100644
>>> --- a/vl.c
>>> +++ b/vl.c
>>> @@ -202,6 +202,7 @@ int smp_cpus = 1;
>>>  int max_cpus = 0;
>>>  int smp_cores = 1;
>>>  int smp_threads = 1;
>>> +int usb_on = 0;
>>>  #ifdef CONFIG_VNC
>>>  const char *vnc_display;
>>>  #endif
>>> @@ -758,6 +759,21 @@ static int bt_parse(const char *opt)
>>>      return 1;
>>>  }
>>>
>>> +static int get_usb_opt(QemuOpts *opts)
>>> +{
>>> +    const char *usb_opt = NULL;
>>
>> Useless initializer.
> Thanks. I will remove it.
>>
>>> +    int usb_on = 0;
>>> +
>>> +    if (NULL == qemu_opt_get(opts, "usb"))
>>> +        qemu_opt_set(opts, "usb", "on");
>>
>> Why are you changing opts?
> USB is enabled by default when there is no usb option setting.
> For example,
> using  # qemu-system-ppc64 -machine type=pseries
> There is no usb option, but usb is set on.

Isn't it off by default for at least some machines now?

Anyway, I don't see why we need to update opts.  Who's using the updated
opts?

>>> +
>>> +    usb_opt = qemu_opt_get(opts, "usb");
>>> +    if (usb_opt && strcmp(usb_opt, "on") == 0)
>>
>> Please don't duplicate parsing of bools; use qemu_opt_get_bool().
> OK.
>>
>>> +        usb_on = 1;
>>> +
>>> +    return usb_on;
>>> +}
>>> +
>>>  /***********************************************************/
>>>  /* QEMU Block devices */
>>>
>>> @@ -3356,6 +3372,7 @@ int main(int argc, char **argv, char **envp)
>>>          kernel_filename = qemu_opt_get(machine_opts, "kernel");
>>>          initrd_filename = qemu_opt_get(machine_opts, "initrd");
>>>          kernel_cmdline = qemu_opt_get(machine_opts, "append");
>>> +        usb_on = get_usb_opt(machine_opts);
>>
>> Anything wrong with
>>
>>         usb_on = qemu_opt_get_bool(machine_opts, "usb", 0);
>>
>> ?
>>
>>>      } else {
>>>          kernel_filename = initrd_filename = kernel_cmdline = NULL;
>>>      }
>>
>> Your new global usb_on is still unused, and it's not integrated with
>> -usb.  I doubt it can be merged that way.
>>
> It is used in spapr.c. In the front of this patch, it is used.
> It seems that this is not good.
> Maybe it is better to move the options setting  to spapr.c.

Dang, I missed that.  Sorry for the noise.