Changeset
hw/usb/host-libusb.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++
hw/usb/host-stub.c   |  9 ++++++++
qapi/misc.json       | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 135 insertions(+)
Git apply log
Switched to a new branch '1523698174-22832-1-git-send-email-agk@godking.net'
Applying: qapi: [PATCH v2] Implement query-usbhost QMP command
To https://github.com/patchew-project/qemu
 * [new tag]         patchew/1523698174-22832-1-git-send-email-agk@godking.net -> patchew/1523698174-22832-1-git-send-email-agk@godking.net
Test passed: checkpatch

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Test passed: docker-mingw@fedora

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Test passed: docker-build@min-glib

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Test passed: s390x

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[Qemu-devel] qapi: [PATCH v2] Implement query-usbhost QMP command
Posted by Alexander Kappner, 13 weeks ago
Implement a QMP command similar to the HMP's "info usbhost" command.
This allows a QMP client to query which USB devices may be available
for redirection. Because the availability of the command needs to
depend on the target's (not the build host's) USB configuration,
a stub function in host-stub.c is provided for targets without USB support.

v2 of this patch resolves build failure under some configurations
without libusb.

Signed-off-by: Alexander Kappner <agk@godking.net>
---
 hw/usb/host-libusb.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/usb/host-stub.c   |  9 ++++++++
 qapi/misc.json       | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 135 insertions(+)

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index 1b0be07..efdf577 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -40,6 +40,7 @@
 #include <libusb.h>
 
 #include "qapi/error.h"
+#include "qapi/qapi-commands-misc.h"
 #include "qemu-common.h"
 #include "monitor/monitor.h"
 #include "qemu/error-report.h"
@@ -1743,6 +1744,69 @@ bool usb_host_dev_is_scsi_storage(USBDevice *ud)
     return is_scsi_storage;
 }
 
+UsbDeviceInfoList *qmp_query_usbhost(Error **errp)
+{
+    UsbDeviceInfoList *usb_list = NULL;
+    UsbDeviceInfoList *info;
+    libusb_device **devs = NULL;
+    struct libusb_device_descriptor ddesc;
+    char port[16];
+    int i, n;
+
+    if (usb_host_init() != 0) {
+        return NULL;
+    }
+    n = libusb_get_device_list(ctx, &devs);
+
+    for (i = 0; i < n; i++) {
+        if (libusb_get_device_descriptor(devs[i], &ddesc) != 0) {
+            continue;
+        }
+        if (ddesc.bDeviceClass == LIBUSB_CLASS_HUB) {
+            continue;
+        }
+        usb_host_get_port(devs[i], port, sizeof(port));
+        info = g_new0(UsbDeviceInfoList, 1);
+        info->value = g_new0(UsbDeviceInfo, 1);
+        info->value->id_vendor = ddesc.idVendor;
+        info->value->bus_num = libusb_get_bus_number(devs[i]);
+        info->value->dev_addr = libusb_get_device_address(devs[i]);
+        info->value->id_product = ddesc.idProduct;
+        info->value->b_device_class = ddesc.bDeviceClass;
+        info->value->speed = libusb_get_device_speed(devs[i]);
+        info->next = usb_list;
+        usb_list = info;
+
+        if (ddesc.iProduct) {
+            libusb_device_handle *handle;
+            if (libusb_open(devs[i], &handle) == 0) {
+                unsigned char name[64] = "";
+                libusb_get_string_descriptor_ascii(handle,
+                                                   ddesc.iProduct,
+                                                   name, sizeof(name));
+                libusb_close(handle);
+                info->value->str_product = g_strdup((gchar *)name);
+            }
+        } else
+            info->value->str_product = NULL;
+
+        if (ddesc.iManufacturer) {
+            libusb_device_handle *handle;
+            if (libusb_open(devs[i], &handle) == 0) {
+                unsigned char name[64] = "";
+                libusb_get_string_descriptor_ascii(handle,
+                                                   ddesc.iManufacturer,
+                                                   name, sizeof(name));
+                libusb_close(handle);
+                info->value->str_manufacturer = g_strdup((gchar *)name);
+            }
+        } else
+        info->value->str_manufacturer = NULL;
+    }
+    libusb_free_device_list(devs, 1);
+    return usb_list;
+}
+
 void hmp_info_usbhost(Monitor *mon, const QDict *qdict)
 {
     libusb_device **devs = NULL;
diff --git a/hw/usb/host-stub.c b/hw/usb/host-stub.c
index 41d93ec..fd227c4 100644
--- a/hw/usb/host-stub.c
+++ b/hw/usb/host-stub.c
@@ -35,6 +35,9 @@
 #include "ui/console.h"
 #include "hw/usb.h"
 #include "monitor/monitor.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-misc.h"
+#include "qapi/qmp/qerror.h"
 
 void hmp_info_usbhost(Monitor *mon, const QDict *qdict)
 {
@@ -45,3 +48,9 @@ bool usb_host_dev_is_scsi_storage(USBDevice *ud)
 {
     return false;
 }
+
+UsbDeviceInfoList *qmp_query_usbhost(Error **errp)
+{
+    error_setg(errp, QERR_FEATURE_DISABLED, "usb");
+    return NULL;
+};
diff --git a/qapi/misc.json b/qapi/misc.json
index 5636f4a..19a1453 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -270,6 +270,46 @@
 { 'command': 'query-kvm', 'returns': 'KvmInfo' }
 
 ##
+# @query-usbhost:
+#
+# Returns information about USB devices available on the host
+#
+# Returns: a [UsbDeviceInfo]. Returns an error if compiled without
+# CONFIG_USB_LIBUSB
+#
+# Since: TODO (maintainer insert version number if mainlined)
+#
+# Example:
+#
+# -> {"execute": "query-usbhost" }
+# {
+#     "return": [
+#         {
+#             "b_device_class": 239,
+#             "id_product": 793,
+#             "id_vendor": 3468,
+#             "speed": 3,
+#             "str_manufacturer": "Schiit Audio",
+#             "str_product": "Schiit Modi Uber"
+#             "bus_num": 5,
+#             "dev_addr": 21
+#         },
+#         {
+#             "b_device_class": 0,
+#             "id_product": 6944,
+#             "id_vendor": 6940,
+#             "speed": 2,
+#             "str_manufacturer": "Corsair",
+#             "str_product": "Corsair STRAFE RGB Gaming Keyboard"
+#             "bus_num": 5,
+#             "dev_addr": 35
+#         }
+#     ]
+# }
+##
+{ 'command': 'query-usbhost', 'returns': ['UsbDeviceInfo'] }
+
+##
 # @UuidInfo:
 #
 # Guest UUID information (Universally Unique Identifier).
@@ -876,6 +916,28 @@
            'regions': ['PciMemoryRegion']} }
 
 ##
+# @UsbDeviceInfo:
+#
+# @speed: the speed
+#
+# @id_vendor: idVendor field from device descriptor
+#
+# @id_product: idProduct field from device descriptor
+#
+# @str_product: string descriptor referenced by iProduct index, if any
+#
+# @str_manufacturer: string descriptor referenced by iManufacturer index, if any
+#
+# @dev_addr: address on bus that device is connected to
+#
+# @bus_num: bus number device is connected to
+##
+{ 'struct': 'UsbDeviceInfo',
+  'data':
+  {'speed': 'int', 'id_vendor': 'int', 'id_product' : 'int', 'str_product': 'str',
+   'b_device_class': 'int', 'str_manufacturer' : 'str', 'dev_addr' : 'int', 'bus_num' : 'int'} }
+
+##
 # @PciInfo:
 #
 # Information about a PCI bus
-- 
2.1.4


Re: [Qemu-devel] qapi: [PATCH v2] Implement query-usbhost QMP command
Posted by Gerd Hoffmann, 13 weeks ago
On Sat, Apr 14, 2018 at 02:29:34AM -0700, Alexander Kappner wrote:
> Implement a QMP command similar to the HMP's "info usbhost" command.

The hmp version of the command should be switched over to call the
qmp_query_usbhost() and pretty-print the qapi struct then, to make
sure hmp and qmp versions of the command deliver consistent results.

> This allows a QMP client to query which USB devices may be available
> for redirection.

I'm wondering what the use case is?

At least libvirt sandboxes qemu, for security reasons, and you wouldn't
get any useful results because qemu hasn't the permissions needed to
scan the usb bus.

>  ##
> +# @query-usbhost:
> +#
> +# Returns information about USB devices available on the host
> +#
> +# Returns: a [UsbDeviceInfo]. Returns an error if compiled without
> +# CONFIG_USB_LIBUSB
> +#
> +# Since: TODO (maintainer insert version number if mainlined)

Will not make it into 2.12, so 2.13.

> +# @UsbDeviceInfo:
> +#
> +# @speed: the speed

Use an enum for this?

> +# @id_vendor: idVendor field from device descriptor
> +#
> +# @id_product: idProduct field from device descriptor
> +#
> +# @str_product: string descriptor referenced by iProduct index, if any
> +#
> +# @str_manufacturer: string descriptor referenced by iManufacturer index, if any
> +#
> +# @dev_addr: address on bus that device is connected to
> +#
> +# @bus_num: bus number device is connected to

No port?

cheers,
  Gerd


Re: [Qemu-devel] qapi: [PATCH v2] Implement query-usbhost QMP command
Posted by Alexander Kappner, 13 weeks ago
Hi Gerd,

thanks for reviewing. I'll follow up with a v3 of the patch addressing your proposed changes.

>> This allows a QMP client to query which USB devices may be available
>> for redirection.

> At least libvirt sandboxes qemu, for security reasons, and you wouldn't
> get any useful results because qemu hasn't the permissions needed to
> scan the usb bus.
Then at least this tells you that you can't make anything available via redirection either, which is also useful information.

> I'm wondering what the use case is?
I'm working on a smartphone client that talks to a QEMU instance via QMP, and that allows the user to switch USB devices between host and QEMU guest. This removes the need for a separate set of input devices permanently assigned to the host (since if I pass through a keyboard/mouse to the VM, I can't use that same keyboard/mouse to run a command that re-attaches those devices to the host, so I need some external channel). Basically using the phone as a KVM switch.

Best
Alexander

On 04/16/2018 01:29 AM, Gerd Hoffmann wrote:
> On Sat, Apr 14, 2018 at 02:29:34AM -0700, Alexander Kappner wrote:
>> Implement a QMP command similar to the HMP's "info usbhost" command.
> 
> The hmp version of the command should be switched over to call the
> qmp_query_usbhost() and pretty-print the qapi struct then, to make
> sure hmp and qmp versions of the command deliver consistent results.
> 
>> This allows a QMP client to query which USB devices may be available
>> for redirection.
> 
> I'm wondering what the use case is?
> 
> At least libvirt sandboxes qemu, for security reasons, and you wouldn't
> get any useful results because qemu hasn't the permissions needed to
> scan the usb bus.
> 
>>  ##
>> +# @query-usbhost:
>> +#
>> +# Returns information about USB devices available on the host
>> +#
>> +# Returns: a [UsbDeviceInfo]. Returns an error if compiled without
>> +# CONFIG_USB_LIBUSB
>> +#
>> +# Since: TODO (maintainer insert version number if mainlined)
> 
> Will not make it into 2.12, so 2.13.
> 
>> +# @UsbDeviceInfo:
>> +#
>> +# @speed: the speed
> 
> Use an enum for this?
> 
>> +# @id_vendor: idVendor field from device descriptor
>> +#
>> +# @id_product: idProduct field from device descriptor
>> +#
>> +# @str_product: string descriptor referenced by iProduct index, if any
>> +#
>> +# @str_manufacturer: string descriptor referenced by iManufacturer index, if any
>> +#
>> +# @dev_addr: address on bus that device is connected to
>> +#
>> +# @bus_num: bus number device is connected to
> 
> No port?
> 
> cheers,
>   Gerd
> 

Re: [Qemu-devel] qapi: [PATCH v2] Implement query-usbhost QMP command
Posted by Gerd Hoffmann, 13 weeks ago
On Mon, Apr 16, 2018 at 03:52:03PM -0700, Alexander Kappner wrote:
> Hi Gerd,
> 
> thanks for reviewing. I'll follow up with a v3 of the patch addressing your proposed changes.
> 
> >> This allows a QMP client to query which USB devices may be available
> >> for redirection.
> 
> > At least libvirt sandboxes qemu, for security reasons, and you wouldn't
> > get any useful results because qemu hasn't the permissions needed to
> > scan the usb bus.
> Then at least this tells you that you can't make anything available via redirection either, which is also useful information.

Well, you can, but you have to go through libvirt instead.  Libvirt will
whitelist the usb device you want assign then (and only that one) so
qemu can access it.

> > I'm wondering what the use case is?

> I'm working on a smartphone client that talks to a QEMU instance via
> QMP, and that allows the user to switch USB devices between host and
> QEMU guest. This removes the need for a separate set of input devices
> permanently assigned to the host (since if I pass through a
> keyboard/mouse to the VM, I can't use that same keyboard/mouse to run
> a command that re-attaches those devices to the host, so I need some
> external channel). Basically using the phone as a KVM switch.

That wouldn't work for any libvirt-managed guests.

Also: Do you know input-linux (see ui/input-linux.c)?  That allows
switching input devices between host and (one) guest by keyboard hotkey.

cheers,
  Gerd


Re: [Qemu-devel] qapi: [PATCH v2] Implement query-usbhost QMP command
Posted by Eric Blake, 12 weeks ago
On 04/14/2018 04:29 AM, Alexander Kappner wrote:
> Implement a QMP command similar to the HMP's "info usbhost" command.
> This allows a QMP client to query which USB devices may be available
> for redirection. Because the availability of the command needs to
> depend on the target's (not the build host's) USB configuration,
> a stub function in host-stub.c is provided for targets without USB support.
> 
> v2 of this patch resolves build failure under some configurations
> without libusb.
> 
> Signed-off-by: Alexander Kappner <agk@godking.net>
> ---
>  hw/usb/host-libusb.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/usb/host-stub.c   |  9 ++++++++
>  qapi/misc.json       | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 135 insertions(+)
> 

> +++ b/qapi/misc.json
> @@ -270,6 +270,46 @@
>  { 'command': 'query-kvm', 'returns': 'KvmInfo' }
>  
>  ##
> +# @query-usbhost:
> +#
> +# Returns information about USB devices available on the host
> +#
> +# Returns: a [UsbDeviceInfo]. Returns an error if compiled without
> +# CONFIG_USB_LIBUSB

s/a [UsbDeviceInfo]/a list of UsbDeviceInfo

> +#
> +# Since: TODO (maintainer insert version number if mainlined)

2.13 (it's easier to guess the next version, on the likely chance that
it does not need tweaking, than it is to force the maintainer to have to
tweak the patch on acceptance)


> +##
> +{ 'command': 'query-usbhost', 'returns': ['UsbDeviceInfo'] }
> +
> +##
>  # @UuidInfo:
>  #
>  # Guest UUID information (Universally Unique Identifier).
> @@ -876,6 +916,28 @@
>             'regions': ['PciMemoryRegion']} }
>  
>  ##
> +# @UsbDeviceInfo:
> +#
> +# @speed: the speed
> +#
> +# @id_vendor: idVendor field from device descriptor

Please, new QMP interfaces should favor '-' over '_' in naming; so this
should be id-vendor, and so on.

> +#
> +# @id_product: idProduct field from device descriptor
> +#
> +# @str_product: string descriptor referenced by iProduct index, if any

What's the difference between idProduct and iProduct in the text here?

> +#
> +# @str_manufacturer: string descriptor referenced by iManufacturer index, if any

Is the 'str_' (or my preferred switch to 'str-') prefix necessary; or
can this field just be 'manufacturer'?

> +#
> +# @dev_addr: address on bus that device is connected to
> +#
> +# @bus_num: bus number device is connected to
> +##
> +{ 'struct': 'UsbDeviceInfo',
> +  'data':
> +  {'speed': 'int', 'id_vendor': 'int', 'id_product' : 'int', 'str_product': 'str',
> +   'b_device_class': 'int', 'str_manufacturer' : 'str', 'dev_addr' : 'int', 'bus_num' : 'int'} }

Long line; please fit things within 80 columns.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org