Patchwork [Qemu-ppc,v8,1/2] Add USB option in machine options

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Submitter zhlcindy@gmail.com
Date Aug. 14, 2012, 5:49 p.m.
Message ID <1344966575-25952-1-git-send-email-zhlcindy@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/177399/
State New
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Comments

zhlcindy@gmail.com - Aug. 14, 2012, 5:49 p.m.
When -usb option is used, global varible usb_enabled is set.
And all the plafrom will create one USB controller according
to this variable. In fact, global varibles make code hard
to read.

So this patch is to remove global variable usb_enabled and
add USB option in machine options. All the plaforms will get
USB option value from machine options.

USB option of machine options will be set either by:
  * -usb
  * -machine type=pseries,usb=on

Both these ways can work now. They both set USB option in
machine options. In the future, the first way will be removed.

Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
---
 v7->v8 : 
  * Declare usb_enabled() and set_usb_option() in sysemu.h
  * Separate USB enablement on sPAPR platform.

 hw/nseries.c      |    2 +-
 hw/pc_piix.c      |    2 +-
 hw/ppc_newworld.c |    4 ++--
 hw/ppc_oldworld.c |    2 +-
 hw/ppc_prep.c     |    2 +-
 hw/pxa2xx.c       |    4 ++--
 hw/realview.c     |    2 +-
 hw/versatilepb.c  |    2 +-
 qemu-config.c     |    4 ++++
 sysemu.h          |    5 ++++-
 vl.c              |   34 ++++++++++++++++++++++++++++------
 11 files changed, 46 insertions(+), 17 deletions(-)
Alexander Graf - Aug. 14, 2012, 6:08 p.m.
On 14.08.2012, at 19:49, Li Zhang <zhlcindy@gmail.com> wrote:

> When -usb option is used, global varible usb_enabled is set.
> And all the plafrom will create one USB controller according
> to this variable. In fact, global varibles make code hard
> to read.
> 
> So this patch is to remove global variable usb_enabled and
> add USB option in machine options. All the plaforms will get
> USB option value from machine options.
> 
> USB option of machine options will be set either by:
>  * -usb
>  * -machine type=pseries,usb=on
> 
> Both these ways can work now. They both set USB option in
> machine options. In the future, the first way will be removed.
> 
> Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
> ---
> v7->v8 : 
>  * Declare usb_enabled() and set_usb_option() in sysemu.h
>  * Separate USB enablement on sPAPR platform.
> 
> hw/nseries.c      |    2 +-
> hw/pc_piix.c      |    2 +-
> hw/ppc_newworld.c |    4 ++--
> hw/ppc_oldworld.c |    2 +-
> hw/ppc_prep.c     |    2 +-
> hw/pxa2xx.c       |    4 ++--
> hw/realview.c     |    2 +-
> hw/versatilepb.c  |    2 +-
> qemu-config.c     |    4 ++++
> sysemu.h          |    5 ++++-
> vl.c              |   34 ++++++++++++++++++++++++++++------
> 11 files changed, 46 insertions(+), 17 deletions(-)
> 
> diff --git a/hw/nseries.c b/hw/nseries.c
> index 4df2670..c67e95a 100644
> --- a/hw/nseries.c
> +++ b/hw/nseries.c
> @@ -1322,7 +1322,7 @@ static void n8x0_init(ram_addr_t ram_size, const char *boot_device,
>     n8x0_dss_setup(s);
>     n8x0_cbus_setup(s);
>     n8x0_uart_setup(s);
> -    if (usb_enabled)
> +    if (usb_enabled(false))
>         n8x0_usb_setup(s);
> 
>     if (kernel_filename) {
> diff --git a/hw/pc_piix.c b/hw/pc_piix.c
> index 0c0096f..b662192 100644
> --- a/hw/pc_piix.c
> +++ b/hw/pc_piix.c
> @@ -267,7 +267,7 @@ static void pc_init1(MemoryRegion *system_memory,
>     pc_cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device,
>                  floppy, idebus[0], idebus[1], rtc_state);
> 
> -    if (pci_enabled && usb_enabled) {
> +    if (pci_enabled && usb_enabled(false)) {
>         pci_create_simple(pci_bus, piix3_devfn + 2, "piix3-usb-uhci");
>     }
> 
> diff --git a/hw/ppc_newworld.c b/hw/ppc_newworld.c
> index 4e2a6e6..fe92491 100644
> --- a/hw/ppc_newworld.c
> +++ b/hw/ppc_newworld.c
> @@ -350,7 +350,7 @@ static void ppc_core99_init (ram_addr_t ram_size,
> 
>     /* cuda also initialize ADB */
>     if (machine_arch == ARCH_MAC99_U3) {
> -        usb_enabled = 1;
> +         set_usb_option(true);

Semantically, this one sets the default usb_enabled to true. Just make the usb_enabled() call get its default value as true when arch == mac99_u3.

>     }
>     cuda_init(&cuda_mem, pic[0x19]);
> 
> @@ -360,7 +360,7 @@ static void ppc_core99_init (ram_addr_t ram_size,
>     macio_init(pci_bus, PCI_DEVICE_ID_APPLE_UNI_N_KEYL, 0, pic_mem,
>                dbdma_mem, cuda_mem, NULL, 3, ide_mem, escc_bar);
> 
> -    if (usb_enabled) {
> +    if (usb_enabled(true)) {

Why true?

>         pci_create_simple(pci_bus, -1, "pci-ohci");
>     }
> 
> diff --git a/hw/ppc_oldworld.c b/hw/ppc_oldworld.c
> index f2c6908..a62b3d8 100644
> --- a/hw/ppc_oldworld.c
> +++ b/hw/ppc_oldworld.c
> @@ -286,7 +286,7 @@ static void ppc_heathrow_init (ram_addr_t ram_size,
>     macio_init(pci_bus, PCI_DEVICE_ID_APPLE_343S1201, 1, pic_mem,
>                dbdma_mem, cuda_mem, nvr, 2, ide_mem, escc_bar);
> 
> -    if (usb_enabled) {
> +    if (usb_enabled(true)) {

Why true? Same for all occurencex of true as default below. Today, we always default to false, no?

>         pci_create_simple(pci_bus, -1, "pci-ohci");
>     }
> 
> diff --git a/hw/ppc_prep.c b/hw/ppc_prep.c
> index be2b268..84ead22 100644
> --- a/hw/ppc_prep.c
> +++ b/hw/ppc_prep.c
> @@ -661,7 +661,7 @@ static void ppc_prep_init (ram_addr_t ram_size,
>     memory_region_add_subregion(sysmem, 0xFEFF0000, xcsr);
> #endif
> 
> -    if (usb_enabled) {
> +    if (usb_enabled(true)) {
>         pci_create_simple(pci_bus, -1, "pci-ohci");
>     }
> 
> diff --git a/hw/pxa2xx.c b/hw/pxa2xx.c
> index d5f1420..28eb92e 100644
> --- a/hw/pxa2xx.c
> +++ b/hw/pxa2xx.c
> @@ -2108,7 +2108,7 @@ PXA2xxState *pxa270_init(MemoryRegion *address_space,
>         s->ssp[i] = (SSIBus *)qdev_get_child_bus(dev, "ssi");
>     }
> 
> -    if (usb_enabled) {
> +    if (usb_enabled(true)) {
>         sysbus_create_simple("sysbus-ohci", 0x4c000000,
>                         qdev_get_gpio_in(s->pic, PXA2XX_PIC_USBH1));
>     }
> @@ -2239,7 +2239,7 @@ PXA2xxState *pxa255_init(MemoryRegion *address_space, unsigned int sdram_size)
>         s->ssp[i] = (SSIBus *)qdev_get_child_bus(dev, "ssi");
>     }
> 
> -    if (usb_enabled) {
> +    if (usb_enabled(false)) {
>         sysbus_create_simple("sysbus-ohci", 0x4c000000,
>                         qdev_get_gpio_in(s->pic, PXA2XX_PIC_USBH1));
>     }
> diff --git a/hw/realview.c b/hw/realview.c
> index 19db4d0..a53f327 100644
> --- a/hw/realview.c
> +++ b/hw/realview.c
> @@ -227,7 +227,7 @@ static void realview_init(ram_addr_t ram_size,
>         sysbus_connect_irq(busdev, 2, pic[50]);
>         sysbus_connect_irq(busdev, 3, pic[51]);
>         pci_bus = (PCIBus *)qdev_get_child_bus(dev, "pci");
> -        if (usb_enabled) {
> +        if (usb_enabled(true)) {
>             pci_create_simple(pci_bus, -1, "pci-ohci");
>         }
>         n = drive_get_max_bus(IF_SCSI);
> diff --git a/hw/versatilepb.c b/hw/versatilepb.c
> index 4fd5d9b..f76671c 100644
> --- a/hw/versatilepb.c
> +++ b/hw/versatilepb.c
> @@ -247,7 +247,7 @@ static void versatile_init(ram_addr_t ram_size,
>             pci_nic_init_nofail(nd, "rtl8139", NULL);
>         }
>     }
> -    if (usb_enabled) {
> +    if (usb_enabled(false)) {
>         pci_create_simple(pci_bus, -1, "pci-ohci");
>     }
>     n = drive_get_max_bus(IF_SCSI);
> diff --git a/qemu-config.c b/qemu-config.c
> index 5c3296b..b86ee36 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -595,6 +595,10 @@ static QemuOptsList qemu_machine_opts = {
>             .name = "dt_compatible",
>             .type = QEMU_OPT_STRING,
>             .help = "Overrides the \"compatible\" property of the dt root node",
> +        },{
> +            .name = "usb",
> +            .type = QEMU_OPT_BOOL,
> +            .help = "Set on/off to enable/disable usb",
>         },
>         { /* End of list */ }
>     },
> diff --git a/sysemu.h b/sysemu.h
> index 4669348..3492fef 100644
> --- a/sysemu.h
> +++ b/sysemu.h
> @@ -118,7 +118,6 @@ extern const char *keyboard_layout;
> extern int win2k_install_hack;
> extern int alt_grab;
> extern int ctrl_grab;
> -extern int usb_enabled;
> extern int smp_cpus;
> extern int max_cpus;
> extern int cursor_hide;
> @@ -188,4 +187,8 @@ void register_devices(void);
> void add_boot_device_path(int32_t bootindex, DeviceState *dev,
>                           const char *suffix);
> char *get_boot_devices_list(uint32_t *size);
> +
> +bool usb_enabled(bool default_usb);
> +void set_usb_option(bool usb_option);

I don't think we need an exported helper to set the option. Machines only ever want to be able to override the default.


Alex

> +
> #endif
> diff --git a/vl.c b/vl.c
> index d01256a..bf51249 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -198,7 +198,6 @@ CharDriverState *serial_hds[MAX_SERIAL_PORTS];
> CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
> CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
> int win2k_install_hack = 0;
> -int usb_enabled = 0;
> int singlestep = 0;
> int smp_cpus = 1;
> int max_cpus = 0;
> @@ -765,6 +764,27 @@ static int bt_parse(const char *opt)
>     return 1;
> }
> 
> +/*********Qemu USB setting******/
> +bool usb_enabled(bool default_usb)
> +{
> +    QemuOpts *mach_opts;
> +    mach_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
> +    if (mach_opts) {
> +        return qemu_opt_get_bool(mach_opts, "usb", default_usb);
> +    }
> +    return default_usb;
> +}
> +
> +void set_usb_option(bool usb_option)
> +{
> +    QemuOpts *mach_opts;
> +    mach_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
> +    if (mach_opts) {
> +        qemu_opt_set_bool(mach_opts, "usb", usb_option);
> +    }
> +}
> +
> +
> /***********************************************************/
> /* QEMU Block devices */
> 
> @@ -1053,8 +1073,9 @@ static int usb_device_add(const char *devname)
>     const char *p;
>     USBDevice *dev = NULL;
> 
> -    if (!usb_enabled)
> +    if (!usb_enabled(false)) {
>         return -1;
> +    }
> 
>     /* drivers with .usbdevice_name entry in USBDeviceInfo */
>     dev = usbdevice_create(devname);
> @@ -1090,8 +1111,9 @@ static int usb_device_del(const char *devname)
>     if (strstart(devname, "host:", &p))
>         return usb_host_device_close(p);
> 
> -    if (!usb_enabled)
> +    if (!usb_enabled(false)) {
>         return -1;
> +    }
> 
>     p = strchr(devname, '.');
>     if (!p)
> @@ -3027,10 +3049,10 @@ int main(int argc, char **argv, char **envp)
>                 }
>                 break;
>             case QEMU_OPTION_usb:
> -                usb_enabled = 1;
> +                set_usb_option(true);
>                 break;
>             case QEMU_OPTION_usbdevice:
> -                usb_enabled = 1;
> +                set_usb_option(true);
>                 add_device_config(DEV_USB, optarg);
>                 break;
>             case QEMU_OPTION_device:
> @@ -3578,7 +3600,7 @@ int main(int argc, char **argv, char **envp)
>     current_machine = machine;
> 
>     /* init USB devices */
> -    if (usb_enabled) {
> +    if (usb_enabled(false)) {
>         if (foreach_device_config(DEV_USB, usb_parse) < 0)
>             exit(1);
>     }
> -- 
> 1.7.7.6
>
zhlcindy@gmail.com - Aug. 15, 2012, 1:23 a.m.
On Wed, Aug 15, 2012 at 2:08 AM, Alexander Graf <agraf@suse.de> wrote:
>
>
> On 14.08.2012, at 19:49, Li Zhang <zhlcindy@gmail.com> wrote:
>
>> When -usb option is used, global varible usb_enabled is set.
>> And all the plafrom will create one USB controller according
>> to this variable. In fact, global varibles make code hard
>> to read.
>>
>> So this patch is to remove global variable usb_enabled and
>> add USB option in machine options. All the plaforms will get
>> USB option value from machine options.
>>
>> USB option of machine options will be set either by:
>>  * -usb
>>  * -machine type=pseries,usb=on
>>
>> Both these ways can work now. They both set USB option in
>> machine options. In the future, the first way will be removed.
>>
>> Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
>> ---
>> v7->v8 :
>>  * Declare usb_enabled() and set_usb_option() in sysemu.h
>>  * Separate USB enablement on sPAPR platform.
>>
>> hw/nseries.c      |    2 +-
>> hw/pc_piix.c      |    2 +-
>> hw/ppc_newworld.c |    4 ++--
>> hw/ppc_oldworld.c |    2 +-
>> hw/ppc_prep.c     |    2 +-
>> hw/pxa2xx.c       |    4 ++--
>> hw/realview.c     |    2 +-
>> hw/versatilepb.c  |    2 +-
>> qemu-config.c     |    4 ++++
>> sysemu.h          |    5 ++++-
>> vl.c              |   34 ++++++++++++++++++++++++++++------
>> 11 files changed, 46 insertions(+), 17 deletions(-)
>>
>> diff --git a/hw/nseries.c b/hw/nseries.c
>> index 4df2670..c67e95a 100644
>> --- a/hw/nseries.c
>> +++ b/hw/nseries.c
>> @@ -1322,7 +1322,7 @@ static void n8x0_init(ram_addr_t ram_size, const char *boot_device,
>>     n8x0_dss_setup(s);
>>     n8x0_cbus_setup(s);
>>     n8x0_uart_setup(s);
>> -    if (usb_enabled)
>> +    if (usb_enabled(false))
>>         n8x0_usb_setup(s);
>>
>>     if (kernel_filename) {
>> diff --git a/hw/pc_piix.c b/hw/pc_piix.c
>> index 0c0096f..b662192 100644
>> --- a/hw/pc_piix.c
>> +++ b/hw/pc_piix.c
>> @@ -267,7 +267,7 @@ static void pc_init1(MemoryRegion *system_memory,
>>     pc_cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device,
>>                  floppy, idebus[0], idebus[1], rtc_state);
>>
>> -    if (pci_enabled && usb_enabled) {
>> +    if (pci_enabled && usb_enabled(false)) {
>>         pci_create_simple(pci_bus, piix3_devfn + 2, "piix3-usb-uhci");
>>     }
>>
>> diff --git a/hw/ppc_newworld.c b/hw/ppc_newworld.c
>> index 4e2a6e6..fe92491 100644
>> --- a/hw/ppc_newworld.c
>> +++ b/hw/ppc_newworld.c
>> @@ -350,7 +350,7 @@ static void ppc_core99_init (ram_addr_t ram_size,
>>
>>     /* cuda also initialize ADB */
>>     if (machine_arch == ARCH_MAC99_U3) {
>> -        usb_enabled = 1;
>> +         set_usb_option(true);
>
> Semantically, this one sets the default usb_enabled to true. Just make the usb_enabled() call get its default value as true when arch == mac99_u3.
>
>>     }
>>     cuda_init(&cuda_mem, pic[0x19]);
>>
>> @@ -360,7 +360,7 @@ static void ppc_core99_init (ram_addr_t ram_size,
>>     macio_init(pci_bus, PCI_DEVICE_ID_APPLE_UNI_N_KEYL, 0, pic_mem,
>>                dbdma_mem, cuda_mem, NULL, 3, ide_mem, escc_bar);
>>
>> -    if (usb_enabled) {
>> +    if (usb_enabled(true)) {
>
> Why true?
Oh, we had some discussion about it before on sPAPR.
So I set the default as true on all ppc platform.
If this is a problem, I will set it as false.

>
>>         pci_create_simple(pci_bus, -1, "pci-ohci");
>>     }
>>
>> diff --git a/hw/ppc_oldworld.c b/hw/ppc_oldworld.c
>> index f2c6908..a62b3d8 100644
>> --- a/hw/ppc_oldworld.c
>> +++ b/hw/ppc_oldworld.c
>> @@ -286,7 +286,7 @@ static void ppc_heathrow_init (ram_addr_t ram_size,
>>     macio_init(pci_bus, PCI_DEVICE_ID_APPLE_343S1201, 1, pic_mem,
>>                dbdma_mem, cuda_mem, nvr, 2, ide_mem, escc_bar);
>>
>> -    if (usb_enabled) {
>> +    if (usb_enabled(true)) {
>
> Why true? Same for all occurencex of true as default below. Today, we always default to false, no?
I considered sPAPR as true before.
It only disable USB by passing "usb=off".
I will set other platforms  as true.

For sPAPR, I may need to consider when VGA is enabled to set USB as true
according to Ben's suggestion. :)

>
>>         pci_create_simple(pci_bus, -1, "pci-ohci");
>>     }
>>
>> diff --git a/hw/ppc_prep.c b/hw/ppc_prep.c
>> index be2b268..84ead22 100644
>> --- a/hw/ppc_prep.c
>> +++ b/hw/ppc_prep.c
>> @@ -661,7 +661,7 @@ static void ppc_prep_init (ram_addr_t ram_size,
>>     memory_region_add_subregion(sysmem, 0xFEFF0000, xcsr);
>> #endif
>>
>> -    if (usb_enabled) {
>> +    if (usb_enabled(true)) {
>>         pci_create_simple(pci_bus, -1, "pci-ohci");
>>     }
>>
>> diff --git a/hw/pxa2xx.c b/hw/pxa2xx.c
>> index d5f1420..28eb92e 100644
>> --- a/hw/pxa2xx.c
>> +++ b/hw/pxa2xx.c
>> @@ -2108,7 +2108,7 @@ PXA2xxState *pxa270_init(MemoryRegion *address_space,
>>         s->ssp[i] = (SSIBus *)qdev_get_child_bus(dev, "ssi");
>>     }
>>
>> -    if (usb_enabled) {
>> +    if (usb_enabled(true)) {
>>         sysbus_create_simple("sysbus-ohci", 0x4c000000,
>>                         qdev_get_gpio_in(s->pic, PXA2XX_PIC_USBH1));
>>     }
>> @@ -2239,7 +2239,7 @@ PXA2xxState *pxa255_init(MemoryRegion *address_space, unsigned int sdram_size)
>>         s->ssp[i] = (SSIBus *)qdev_get_child_bus(dev, "ssi");
>>     }
>>
>> -    if (usb_enabled) {
>> +    if (usb_enabled(false)) {
>>         sysbus_create_simple("sysbus-ohci", 0x4c000000,
>>                         qdev_get_gpio_in(s->pic, PXA2XX_PIC_USBH1));
>>     }
>> diff --git a/hw/realview.c b/hw/realview.c
>> index 19db4d0..a53f327 100644
>> --- a/hw/realview.c
>> +++ b/hw/realview.c
>> @@ -227,7 +227,7 @@ static void realview_init(ram_addr_t ram_size,
>>         sysbus_connect_irq(busdev, 2, pic[50]);
>>         sysbus_connect_irq(busdev, 3, pic[51]);
>>         pci_bus = (PCIBus *)qdev_get_child_bus(dev, "pci");
>> -        if (usb_enabled) {
>> +        if (usb_enabled(true)) {
>>             pci_create_simple(pci_bus, -1, "pci-ohci");
>>         }
>>         n = drive_get_max_bus(IF_SCSI);
>> diff --git a/hw/versatilepb.c b/hw/versatilepb.c
>> index 4fd5d9b..f76671c 100644
>> --- a/hw/versatilepb.c
>> +++ b/hw/versatilepb.c
>> @@ -247,7 +247,7 @@ static void versatile_init(ram_addr_t ram_size,
>>             pci_nic_init_nofail(nd, "rtl8139", NULL);
>>         }
>>     }
>> -    if (usb_enabled) {
>> +    if (usb_enabled(false)) {
>>         pci_create_simple(pci_bus, -1, "pci-ohci");
>>     }
>>     n = drive_get_max_bus(IF_SCSI);
>> diff --git a/qemu-config.c b/qemu-config.c
>> index 5c3296b..b86ee36 100644
>> --- a/qemu-config.c
>> +++ b/qemu-config.c
>> @@ -595,6 +595,10 @@ static QemuOptsList qemu_machine_opts = {
>>             .name = "dt_compatible",
>>             .type = QEMU_OPT_STRING,
>>             .help = "Overrides the \"compatible\" property of the dt root node",
>> +        },{
>> +            .name = "usb",
>> +            .type = QEMU_OPT_BOOL,
>> +            .help = "Set on/off to enable/disable usb",
>>         },
>>         { /* End of list */ }
>>     },
>> diff --git a/sysemu.h b/sysemu.h
>> index 4669348..3492fef 100644
>> --- a/sysemu.h
>> +++ b/sysemu.h
>> @@ -118,7 +118,6 @@ extern const char *keyboard_layout;
>> extern int win2k_install_hack;
>> extern int alt_grab;
>> extern int ctrl_grab;
>> -extern int usb_enabled;
>> extern int smp_cpus;
>> extern int max_cpus;
>> extern int cursor_hide;
>> @@ -188,4 +187,8 @@ void register_devices(void);
>> void add_boot_device_path(int32_t bootindex, DeviceState *dev,
>>                           const char *suffix);
>> char *get_boot_devices_list(uint32_t *size);
>> +
>> +bool usb_enabled(bool default_usb);
>> +void set_usb_option(bool usb_option);
>
> I don't think we need an exported helper to set the option. Machines only ever want to be able to override the default.
>
>
> Alex
>
>> +
>> #endif
>> diff --git a/vl.c b/vl.c
>> index d01256a..bf51249 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -198,7 +198,6 @@ CharDriverState *serial_hds[MAX_SERIAL_PORTS];
>> CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
>> CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
>> int win2k_install_hack = 0;
>> -int usb_enabled = 0;
>> int singlestep = 0;
>> int smp_cpus = 1;
>> int max_cpus = 0;
>> @@ -765,6 +764,27 @@ static int bt_parse(const char *opt)
>>     return 1;
>> }
>>
>> +/*********Qemu USB setting******/
>> +bool usb_enabled(bool default_usb)
>> +{
>> +    QemuOpts *mach_opts;
>> +    mach_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
>> +    if (mach_opts) {
>> +        return qemu_opt_get_bool(mach_opts, "usb", default_usb);
>> +    }
>> +    return default_usb;
>> +}
>> +
>> +void set_usb_option(bool usb_option)
>> +{
>> +    QemuOpts *mach_opts;
>> +    mach_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
>> +    if (mach_opts) {
>> +        qemu_opt_set_bool(mach_opts, "usb", usb_option);
>> +    }
>> +}
>> +
>> +
>> /***********************************************************/
>> /* QEMU Block devices */
>>
>> @@ -1053,8 +1073,9 @@ static int usb_device_add(const char *devname)
>>     const char *p;
>>     USBDevice *dev = NULL;
>>
>> -    if (!usb_enabled)
>> +    if (!usb_enabled(false)) {
>>         return -1;
>> +    }
>>
>>     /* drivers with .usbdevice_name entry in USBDeviceInfo */
>>     dev = usbdevice_create(devname);
>> @@ -1090,8 +1111,9 @@ static int usb_device_del(const char *devname)
>>     if (strstart(devname, "host:", &p))
>>         return usb_host_device_close(p);
>>
>> -    if (!usb_enabled)
>> +    if (!usb_enabled(false)) {
>>         return -1;
>> +    }
>>
>>     p = strchr(devname, '.');
>>     if (!p)
>> @@ -3027,10 +3049,10 @@ int main(int argc, char **argv, char **envp)
>>                 }
>>                 break;
>>             case QEMU_OPTION_usb:
>> -                usb_enabled = 1;
>> +                set_usb_option(true);
>>                 break;
>>             case QEMU_OPTION_usbdevice:
>> -                usb_enabled = 1;
>> +                set_usb_option(true);
>>                 add_device_config(DEV_USB, optarg);
>>                 break;
>>             case QEMU_OPTION_device:
>> @@ -3578,7 +3600,7 @@ int main(int argc, char **argv, char **envp)
>>     current_machine = machine;
>>
>>     /* init USB devices */
>> -    if (usb_enabled) {
>> +    if (usb_enabled(false)) {
>>         if (foreach_device_config(DEV_USB, usb_parse) < 0)
>>             exit(1);
>>     }
>> --
>> 1.7.7.6
>>

Patch

diff --git a/hw/nseries.c b/hw/nseries.c
index 4df2670..c67e95a 100644
--- a/hw/nseries.c
+++ b/hw/nseries.c
@@ -1322,7 +1322,7 @@  static void n8x0_init(ram_addr_t ram_size, const char *boot_device,
     n8x0_dss_setup(s);
     n8x0_cbus_setup(s);
     n8x0_uart_setup(s);
-    if (usb_enabled)
+    if (usb_enabled(false))
         n8x0_usb_setup(s);
 
     if (kernel_filename) {
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 0c0096f..b662192 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -267,7 +267,7 @@  static void pc_init1(MemoryRegion *system_memory,
     pc_cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device,
                  floppy, idebus[0], idebus[1], rtc_state);
 
-    if (pci_enabled && usb_enabled) {
+    if (pci_enabled && usb_enabled(false)) {
         pci_create_simple(pci_bus, piix3_devfn + 2, "piix3-usb-uhci");
     }
 
diff --git a/hw/ppc_newworld.c b/hw/ppc_newworld.c
index 4e2a6e6..fe92491 100644
--- a/hw/ppc_newworld.c
+++ b/hw/ppc_newworld.c
@@ -350,7 +350,7 @@  static void ppc_core99_init (ram_addr_t ram_size,
 
     /* cuda also initialize ADB */
     if (machine_arch == ARCH_MAC99_U3) {
-        usb_enabled = 1;
+         set_usb_option(true);
     }
     cuda_init(&cuda_mem, pic[0x19]);
 
@@ -360,7 +360,7 @@  static void ppc_core99_init (ram_addr_t ram_size,
     macio_init(pci_bus, PCI_DEVICE_ID_APPLE_UNI_N_KEYL, 0, pic_mem,
                dbdma_mem, cuda_mem, NULL, 3, ide_mem, escc_bar);
 
-    if (usb_enabled) {
+    if (usb_enabled(true)) {
         pci_create_simple(pci_bus, -1, "pci-ohci");
     }
 
diff --git a/hw/ppc_oldworld.c b/hw/ppc_oldworld.c
index f2c6908..a62b3d8 100644
--- a/hw/ppc_oldworld.c
+++ b/hw/ppc_oldworld.c
@@ -286,7 +286,7 @@  static void ppc_heathrow_init (ram_addr_t ram_size,
     macio_init(pci_bus, PCI_DEVICE_ID_APPLE_343S1201, 1, pic_mem,
                dbdma_mem, cuda_mem, nvr, 2, ide_mem, escc_bar);
 
-    if (usb_enabled) {
+    if (usb_enabled(true)) {
         pci_create_simple(pci_bus, -1, "pci-ohci");
     }
 
diff --git a/hw/ppc_prep.c b/hw/ppc_prep.c
index be2b268..84ead22 100644
--- a/hw/ppc_prep.c
+++ b/hw/ppc_prep.c
@@ -661,7 +661,7 @@  static void ppc_prep_init (ram_addr_t ram_size,
     memory_region_add_subregion(sysmem, 0xFEFF0000, xcsr);
 #endif
 
-    if (usb_enabled) {
+    if (usb_enabled(true)) {
         pci_create_simple(pci_bus, -1, "pci-ohci");
     }
 
diff --git a/hw/pxa2xx.c b/hw/pxa2xx.c
index d5f1420..28eb92e 100644
--- a/hw/pxa2xx.c
+++ b/hw/pxa2xx.c
@@ -2108,7 +2108,7 @@  PXA2xxState *pxa270_init(MemoryRegion *address_space,
         s->ssp[i] = (SSIBus *)qdev_get_child_bus(dev, "ssi");
     }
 
-    if (usb_enabled) {
+    if (usb_enabled(true)) {
         sysbus_create_simple("sysbus-ohci", 0x4c000000,
                         qdev_get_gpio_in(s->pic, PXA2XX_PIC_USBH1));
     }
@@ -2239,7 +2239,7 @@  PXA2xxState *pxa255_init(MemoryRegion *address_space, unsigned int sdram_size)
         s->ssp[i] = (SSIBus *)qdev_get_child_bus(dev, "ssi");
     }
 
-    if (usb_enabled) {
+    if (usb_enabled(false)) {
         sysbus_create_simple("sysbus-ohci", 0x4c000000,
                         qdev_get_gpio_in(s->pic, PXA2XX_PIC_USBH1));
     }
diff --git a/hw/realview.c b/hw/realview.c
index 19db4d0..a53f327 100644
--- a/hw/realview.c
+++ b/hw/realview.c
@@ -227,7 +227,7 @@  static void realview_init(ram_addr_t ram_size,
         sysbus_connect_irq(busdev, 2, pic[50]);
         sysbus_connect_irq(busdev, 3, pic[51]);
         pci_bus = (PCIBus *)qdev_get_child_bus(dev, "pci");
-        if (usb_enabled) {
+        if (usb_enabled(true)) {
             pci_create_simple(pci_bus, -1, "pci-ohci");
         }
         n = drive_get_max_bus(IF_SCSI);
diff --git a/hw/versatilepb.c b/hw/versatilepb.c
index 4fd5d9b..f76671c 100644
--- a/hw/versatilepb.c
+++ b/hw/versatilepb.c
@@ -247,7 +247,7 @@  static void versatile_init(ram_addr_t ram_size,
             pci_nic_init_nofail(nd, "rtl8139", NULL);
         }
     }
-    if (usb_enabled) {
+    if (usb_enabled(false)) {
         pci_create_simple(pci_bus, -1, "pci-ohci");
     }
     n = drive_get_max_bus(IF_SCSI);
diff --git a/qemu-config.c b/qemu-config.c
index 5c3296b..b86ee36 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -595,6 +595,10 @@  static QemuOptsList qemu_machine_opts = {
             .name = "dt_compatible",
             .type = QEMU_OPT_STRING,
             .help = "Overrides the \"compatible\" property of the dt root node",
+        },{
+            .name = "usb",
+            .type = QEMU_OPT_BOOL,
+            .help = "Set on/off to enable/disable usb",
         },
         { /* End of list */ }
     },
diff --git a/sysemu.h b/sysemu.h
index 4669348..3492fef 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -118,7 +118,6 @@  extern const char *keyboard_layout;
 extern int win2k_install_hack;
 extern int alt_grab;
 extern int ctrl_grab;
-extern int usb_enabled;
 extern int smp_cpus;
 extern int max_cpus;
 extern int cursor_hide;
@@ -188,4 +187,8 @@  void register_devices(void);
 void add_boot_device_path(int32_t bootindex, DeviceState *dev,
                           const char *suffix);
 char *get_boot_devices_list(uint32_t *size);
+
+bool usb_enabled(bool default_usb);
+void set_usb_option(bool usb_option);
+
 #endif
diff --git a/vl.c b/vl.c
index d01256a..bf51249 100644
--- a/vl.c
+++ b/vl.c
@@ -198,7 +198,6 @@  CharDriverState *serial_hds[MAX_SERIAL_PORTS];
 CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
 CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
 int win2k_install_hack = 0;
-int usb_enabled = 0;
 int singlestep = 0;
 int smp_cpus = 1;
 int max_cpus = 0;
@@ -765,6 +764,27 @@  static int bt_parse(const char *opt)
     return 1;
 }
 
+/*********Qemu USB setting******/
+bool usb_enabled(bool default_usb)
+{
+    QemuOpts *mach_opts;
+    mach_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
+    if (mach_opts) {
+        return qemu_opt_get_bool(mach_opts, "usb", default_usb);
+    }
+    return default_usb;
+}
+
+void set_usb_option(bool usb_option)
+{
+    QemuOpts *mach_opts;
+    mach_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
+    if (mach_opts) {
+        qemu_opt_set_bool(mach_opts, "usb", usb_option);
+    }
+}
+
+
 /***********************************************************/
 /* QEMU Block devices */
 
@@ -1053,8 +1073,9 @@  static int usb_device_add(const char *devname)
     const char *p;
     USBDevice *dev = NULL;
 
-    if (!usb_enabled)
+    if (!usb_enabled(false)) {
         return -1;
+    }
 
     /* drivers with .usbdevice_name entry in USBDeviceInfo */
     dev = usbdevice_create(devname);
@@ -1090,8 +1111,9 @@  static int usb_device_del(const char *devname)
     if (strstart(devname, "host:", &p))
         return usb_host_device_close(p);
 
-    if (!usb_enabled)
+    if (!usb_enabled(false)) {
         return -1;
+    }
 
     p = strchr(devname, '.');
     if (!p)
@@ -3027,10 +3049,10 @@  int main(int argc, char **argv, char **envp)
                 }
                 break;
             case QEMU_OPTION_usb:
-                usb_enabled = 1;
+                set_usb_option(true);
                 break;
             case QEMU_OPTION_usbdevice:
-                usb_enabled = 1;
+                set_usb_option(true);
                 add_device_config(DEV_USB, optarg);
                 break;
             case QEMU_OPTION_device:
@@ -3578,7 +3600,7 @@  int main(int argc, char **argv, char **envp)
     current_machine = machine;
 
     /* init USB devices */
-    if (usb_enabled) {
+    if (usb_enabled(false)) {
         if (foreach_device_config(DEV_USB, usb_parse) < 0)
             exit(1);
     }