[PATCH v3 0/3] usb, xen: add pvUSB backend

[PATCH v3 0/3] usb, xen: add pvUSB backend

[Juergen Gross]

This series adds a Xen pvUSB backend driver to qemu. USB devices
connected to the host can be passed through to a Xen guest. The
devices are specified via Xenstore. Access to the devices is done
via host-libusb.c

I've tested the backend with various USB devices (memory sticks,
keyboard, ...).

Changes in V3:
- added new patch 2 (was sent formerly on it's own)
- patch 3 (was 2): multiple small changes as requested by Anthony Perard
- patch 3 (was 2): check for full ring in case of hotplug events as
  requested by Anthony Perard
- patch 3 (was 2): use RING_COPY_REQUEST() instead of RING_GET_REQUEST()
- patch 3 (was 2): add check for required header version and disable
  backend in case header is too old

Changes in V2:
- rebased to current qemu master
- removed support for isoc requests in this series, as the optimal way to
  support those isn't clear yet. Will be added in a followup series.
- several changes as requested by Stefano Stabellini and Konrad Wilk

Changes since RFC:
- open device via qdev_device_add(), making patch 1 obsolete
- modify patch 2 to use isoc passthrough via libusb instead of one
  job per frame

Juergen Gross (3):
  xen: introduce dummy system device
  xen: write information about supported backends
  xen: add pvUSB backend

 hw/usb/Makefile.objs         |    4 +
 hw/usb/xen-usb.c             | 1080 ++++++++++++++++++++++++++++++++++++++++++
 hw/xen/xen_backend.c         |   60 +++
 hw/xen/xen_devconfig.c       |   52 +-
 hw/xenpv/xen_machine_pv.c    |   43 ++
 include/hw/xen/xen_backend.h |    6 +
 include/hw/xen/xen_common.h  |    2 +
 7 files changed, 1197 insertions(+), 50 deletions(-)
 create mode 100644 hw/usb/xen-usb.c

-- 
2.6.6

[PATCH v3 1/3] xen: introduce dummy system device

[Juergen Gross]

Introduce a new dummy system device serving as parent for virtual
buses. This will enable new pv backends to introduce virtual buses
which are removable again opposed to system buses which are meant
to stay once added.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
---
V2: NOT changed, even if requested by Stefano Stabellini: the xen dummy
    system device is needed by virtfs for Xen PV(H) guests, too
---
 hw/xenpv/xen_machine_pv.c    | 40 ++++++++++++++++++++++++++++++++++++++++
 include/hw/xen/xen_backend.h |  1 +
 2 files changed, 41 insertions(+)

diff --git a/hw/xenpv/xen_machine_pv.c b/hw/xenpv/xen_machine_pv.c
index fc13535..48d5bc6 100644
--- a/hw/xenpv/xen_machine_pv.c
+++ b/hw/xenpv/xen_machine_pv.c
@@ -25,10 +25,15 @@
 #include "qemu/osdep.h"
 #include "hw/hw.h"
 #include "hw/boards.h"
+#include "hw/sysbus.h"
 #include "hw/xen/xen_backend.h"
 #include "xen_domainbuild.h"
 #include "sysemu/block-backend.h"
 
+#define TYPE_XENSYSDEV "xensysdev"
+
+DeviceState *xen_sysdev;
+
 static void xen_init_pv(MachineState *machine)
 {
     DriveInfo *dinfo;
@@ -67,6 +72,9 @@ static void xen_init_pv(MachineState *machine)
         break;
     }
 
+    xen_sysdev = qdev_create(NULL, TYPE_XENSYSDEV);
+    qdev_init_nofail(xen_sysdev);
+
     xen_be_register("console", &xen_console_ops);
     xen_be_register("vkbd", &xen_kbdmouse_ops);
     xen_be_register("vfb", &xen_framebuffer_ops);
@@ -101,6 +109,38 @@ static void xen_init_pv(MachineState *machine)
     xen_init_display(xen_domid);
 }
 
+static int xen_sysdev_init(SysBusDevice *dev)
+{
+    return 0;
+}
+
+static Property xen_sysdev_properties[] = {
+    {/* end of property list */},
+};
+
+static void xen_sysdev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+    k->init = xen_sysdev_init;
+    dc->props = xen_sysdev_properties;
+}
+
+static const TypeInfo xensysdev_info = {
+    .name          = TYPE_XENSYSDEV,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SysBusDevice),
+    .class_init    = xen_sysdev_class_init,
+};
+
+static void xenpv_register_types(void)
+{
+    type_register_static(&xensysdev_info);
+}
+
+type_init(xenpv_register_types);
+
 static void xenpv_machine_init(MachineClass *mc)
 {
     mc->desc = "Xen Para-virtualized PC";
diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
index c839eeb..b4b4ff0 100644
--- a/include/hw/xen/xen_backend.h
+++ b/include/hw/xen/xen_backend.h
@@ -60,6 +60,7 @@ extern xc_interface *xen_xc;
 extern xenforeignmemory_handle *xen_fmem;
 extern struct xs_handle *xenstore;
 extern const char *xen_protocol;
+extern DeviceState *xen_sysdev;
 
 /* xenstore helper functions */
 int xenstore_write_str(const char *base, const char *node, const char *val);
-- 
2.6.6

[PATCH v3 2/3] xen: write information about supported backends

[Juergen Gross]

Add a Xenstore directory for each supported pv backend. This will allow
Xen tools to decide which backend type to use in case there are
multiple possibilities.

The information is added under
/local/domain/<backend-domid>/device-model/<domid>/backends
before the "running" state is written to Xenstore. Using a directory
for each backend enables us to add parameters for specific backends
in the future.

This interface is documented in the Xen source repository in the file
docs/misc/qemu-backends.txt

In order to reuse the Xenstore directory creation already present in
hw/xen/xen_devconfig.c move the related functions to
hw/xen/xen_backend.c where they fit better.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V3: Added .backend_register function to XenDevOps in order to have a
    way to let the backend decide whether all prerequisites are met
    for support.

V2: update commit message as requested by Stefano
---
 hw/xen/xen_backend.c         | 60 ++++++++++++++++++++++++++++++++++++++++++++
 hw/xen/xen_devconfig.c       | 52 ++------------------------------------
 include/hw/xen/xen_backend.h |  2 ++
 3 files changed, 64 insertions(+), 50 deletions(-)

diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
index 60575ad..6d8b3a5 100644
--- a/hw/xen/xen_backend.c
+++ b/hw/xen/xen_backend.c
@@ -42,11 +42,35 @@ struct xs_handle *xenstore = NULL;
 const char *xen_protocol;
 
 /* private */
+struct xs_dirs {
+    char *xs_dir;
+    QTAILQ_ENTRY(xs_dirs) list;
+};
+static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = QTAILQ_HEAD_INITIALIZER(xs_cleanup);
+
 static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs = QTAILQ_HEAD_INITIALIZER(xendevs);
 static int debug = 0;
 
 /* ------------------------------------------------------------- */
 
+static void xenstore_cleanup_dir(char *dir)
+{
+    struct xs_dirs *d;
+
+    d = g_malloc(sizeof(*d));
+    d->xs_dir = dir;
+    QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
+}
+
+void xen_config_cleanup(void)
+{
+    struct xs_dirs *d;
+
+    QTAILQ_FOREACH(d, &xs_cleanup, list) {
+        xs_rm(xenstore, 0, d->xs_dir);
+    }
+}
+
 int xenstore_write_str(const char *base, const char *node, const char *val)
 {
     char abspath[XEN_BUFSIZE];
@@ -75,6 +99,28 @@ char *xenstore_read_str(const char *base, const char *node)
     return ret;
 }
 
+int xenstore_mkdir(char *path, int p)
+{
+    struct xs_permissions perms[2] = {{
+            .id    = 0, /* set owner: dom0 */
+        },{
+            .id    = xen_domid,
+            .perms = p,
+        }};
+
+    if (!xs_mkdir(xenstore, 0, path)) {
+        xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", path);
+        return -1;
+    }
+    xenstore_cleanup_dir(g_strdup(path));
+
+    if (!xs_set_permissions(xenstore, 0, path, perms, 2)) {
+        xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", path);
+        return -1;
+    }
+    return 0;
+}
+
 int xenstore_write_int(const char *base, const char *node, int ival)
 {
     char val[12];
@@ -726,6 +772,20 @@ err:
 
 int xen_be_register(const char *type, struct XenDevOps *ops)
 {
+    char path[50];
+    int rc;
+
+    if (ops->backend_register) {
+        rc = ops->backend_register();
+        if (rc) {
+            return rc;
+        }
+    }
+
+    snprintf(path, sizeof (path), "device-model/%u/backends/%s", xen_domid,
+             type);
+    xenstore_mkdir(path, XS_PERM_READ);
+
     return xenstore_scan(type, xen_domid, ops);
 }
 
diff --git a/hw/xen/xen_devconfig.c b/hw/xen/xen_devconfig.c
index 1f30fe4..b7d290d 100644
--- a/hw/xen/xen_devconfig.c
+++ b/hw/xen/xen_devconfig.c
@@ -5,54 +5,6 @@
 
 /* ------------------------------------------------------------- */
 
-struct xs_dirs {
-    char *xs_dir;
-    QTAILQ_ENTRY(xs_dirs) list;
-};
-static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = QTAILQ_HEAD_INITIALIZER(xs_cleanup);
-
-static void xen_config_cleanup_dir(char *dir)
-{
-    struct xs_dirs *d;
-
-    d = g_malloc(sizeof(*d));
-    d->xs_dir = dir;
-    QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
-}
-
-void xen_config_cleanup(void)
-{
-    struct xs_dirs *d;
-
-    QTAILQ_FOREACH(d, &xs_cleanup, list) {
-	xs_rm(xenstore, 0, d->xs_dir);
-    }
-}
-
-/* ------------------------------------------------------------- */
-
-static int xen_config_dev_mkdir(char *dev, int p)
-{
-    struct xs_permissions perms[2] = {{
-            .id    = 0, /* set owner: dom0 */
-        },{
-            .id    = xen_domid,
-            .perms = p,
-        }};
-
-    if (!xs_mkdir(xenstore, 0, dev)) {
-	xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", dev);
-	return -1;
-    }
-    xen_config_cleanup_dir(g_strdup(dev));
-
-    if (!xs_set_permissions(xenstore, 0, dev, perms, 2)) {
-	xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", dev);
-	return -1;
-    }
-    return 0;
-}
-
 static int xen_config_dev_dirs(const char *ftype, const char *btype, int vdev,
 			       char *fe, char *be, int len)
 {
@@ -66,8 +18,8 @@ static int xen_config_dev_dirs(const char *ftype, const char *btype, int vdev,
     snprintf(be, len, "%s/backend/%s/%d/%d", dom, btype, xen_domid, vdev);
     free(dom);
 
-    xen_config_dev_mkdir(fe, XS_PERM_READ | XS_PERM_WRITE);
-    xen_config_dev_mkdir(be, XS_PERM_READ);
+    xenstore_mkdir(fe, XS_PERM_READ | XS_PERM_WRITE);
+    xenstore_mkdir(be, XS_PERM_READ);
     return 0;
 }
 
diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
index b4b4ff0..63364f7 100644
--- a/include/hw/xen/xen_backend.h
+++ b/include/hw/xen/xen_backend.h
@@ -28,6 +28,7 @@ struct XenDevOps {
     int       (*free)(struct XenDevice *xendev);
     void      (*backend_changed)(struct XenDevice *xendev, const char *node);
     void      (*frontend_changed)(struct XenDevice *xendev, const char *node);
+    int       (*backend_register)(void);
 };
 
 struct XenDevice {
@@ -63,6 +64,7 @@ extern const char *xen_protocol;
 extern DeviceState *xen_sysdev;
 
 /* xenstore helper functions */
+int xenstore_mkdir(char *path, int p);
 int xenstore_write_str(const char *base, const char *node, const char *val);
 int xenstore_write_int(const char *base, const char *node, int ival);
 int xenstore_write_int64(const char *base, const char *node, int64_t ival);
-- 
2.6.6

Re: [PATCH v3 2/3] xen: write information about supported backends

[Anthony PERARD]

On Fri, May 06, 2016 at 11:42:45AM +0200, Juergen Gross wrote:
> Add a Xenstore directory for each supported pv backend. This will allow
> Xen tools to decide which backend type to use in case there are
> multiple possibilities.
> 
> The information is added under
> /local/domain/<backend-domid>/device-model/<domid>/backends
> before the "running" state is written to Xenstore. Using a directory
> for each backend enables us to add parameters for specific backends
> in the future.
> 
> This interface is documented in the Xen source repository in the file
> docs/misc/qemu-backends.txt
> 
> In order to reuse the Xenstore directory creation already present in
> hw/xen/xen_devconfig.c move the related functions to
> hw/xen/xen_backend.c where they fit better.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> V3: Added .backend_register function to XenDevOps in order to have a
>     way to let the backend decide whether all prerequisites are met
>     for support.
> 
> V2: update commit message as requested by Stefano
> ---
>  hw/xen/xen_backend.c         | 60 ++++++++++++++++++++++++++++++++++++++++++++
>  hw/xen/xen_devconfig.c       | 52 ++------------------------------------
>  include/hw/xen/xen_backend.h |  2 ++
>  3 files changed, 64 insertions(+), 50 deletions(-)
> 
> diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
> index 60575ad..6d8b3a5 100644
> --- a/hw/xen/xen_backend.c
> +++ b/hw/xen/xen_backend.c
> @@ -42,11 +42,35 @@ struct xs_handle *xenstore = NULL;
>  const char *xen_protocol;
>  
>  /* private */
> +struct xs_dirs {
> +    char *xs_dir;
> +    QTAILQ_ENTRY(xs_dirs) list;
> +};
> +static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = QTAILQ_HEAD_INITIALIZER(xs_cleanup);
> +
>  static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs = QTAILQ_HEAD_INITIALIZER(xendevs);
>  static int debug = 0;
>  
>  /* ------------------------------------------------------------- */
>  
> +static void xenstore_cleanup_dir(char *dir)
> +{
> +    struct xs_dirs *d;
> +
> +    d = g_malloc(sizeof(*d));
> +    d->xs_dir = dir;
> +    QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
> +}
> +
> +void xen_config_cleanup(void)
> +{
> +    struct xs_dirs *d;
> +
> +    QTAILQ_FOREACH(d, &xs_cleanup, list) {
> +        xs_rm(xenstore, 0, d->xs_dir);
> +    }
> +}
> +
>  int xenstore_write_str(const char *base, const char *node, const char *val)
>  {
>      char abspath[XEN_BUFSIZE];
> @@ -75,6 +99,28 @@ char *xenstore_read_str(const char *base, const char *node)
>      return ret;
>  }
>  
> +int xenstore_mkdir(char *path, int p)
> +{
> +    struct xs_permissions perms[2] = {{
> +            .id    = 0, /* set owner: dom0 */
> +        },{
> +            .id    = xen_domid,
> +            .perms = p,
> +        }};
> +
> +    if (!xs_mkdir(xenstore, 0, path)) {
> +        xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", path);
> +        return -1;
> +    }
> +    xenstore_cleanup_dir(g_strdup(path));
> +
> +    if (!xs_set_permissions(xenstore, 0, path, perms, 2)) {
> +        xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", path);
> +        return -1;
> +    }
> +    return 0;
> +}
> +
>  int xenstore_write_int(const char *base, const char *node, int ival)
>  {
>      char val[12];
> @@ -726,6 +772,20 @@ err:
>  
>  int xen_be_register(const char *type, struct XenDevOps *ops)
>  {
> +    char path[50];
> +    int rc;
> +
> +    if (ops->backend_register) {
> +        rc = ops->backend_register();
> +        if (rc) {
> +            return rc;
> +        }
> +    }
> +
> +    snprintf(path, sizeof (path), "device-model/%u/backends/%s", xen_domid,
> +             type);
> +    xenstore_mkdir(path, XS_PERM_READ);

Do you actually need the guest to be able to read those paths?

> +
>      return xenstore_scan(type, xen_domid, ops);
>  }
>  
> diff --git a/hw/xen/xen_devconfig.c b/hw/xen/xen_devconfig.c
> index 1f30fe4..b7d290d 100644
> --- a/hw/xen/xen_devconfig.c
> +++ b/hw/xen/xen_devconfig.c
> @@ -5,54 +5,6 @@
>  
>  /* ------------------------------------------------------------- */
>  
> -struct xs_dirs {
> -    char *xs_dir;
> -    QTAILQ_ENTRY(xs_dirs) list;
> -};
> -static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = QTAILQ_HEAD_INITIALIZER(xs_cleanup);
> -
> -static void xen_config_cleanup_dir(char *dir)
> -{
> -    struct xs_dirs *d;
> -
> -    d = g_malloc(sizeof(*d));
> -    d->xs_dir = dir;
> -    QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
> -}
> -
> -void xen_config_cleanup(void)
> -{
> -    struct xs_dirs *d;
> -
> -    QTAILQ_FOREACH(d, &xs_cleanup, list) {
> -	xs_rm(xenstore, 0, d->xs_dir);
> -    }
> -}
> -
> -/* ------------------------------------------------------------- */
> -
> -static int xen_config_dev_mkdir(char *dev, int p)
> -{
> -    struct xs_permissions perms[2] = {{
> -            .id    = 0, /* set owner: dom0 */
> -        },{
> -            .id    = xen_domid,
> -            .perms = p,
> -        }};
> -

The function looks like it as been tailored to mkdir for config of
backends. So it does not seems out of place.

> -    if (!xs_mkdir(xenstore, 0, dev)) {
> -	xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", dev);
> -	return -1;
> -    }
> -    xen_config_cleanup_dir(g_strdup(dev));
> -
> -    if (!xs_set_permissions(xenstore, 0, dev, perms, 2)) {
> -	xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", dev);
> -	return -1;
> -    }
> -    return 0;
> -}
> -
>  static int xen_config_dev_dirs(const char *ftype, const char *btype, int vdev,
>  			       char *fe, char *be, int len)
>  {
> @@ -66,8 +18,8 @@ static int xen_config_dev_dirs(const char *ftype, const char *btype, int vdev,
>      snprintf(be, len, "%s/backend/%s/%d/%d", dom, btype, xen_domid, vdev);
>      free(dom);
>  
> -    xen_config_dev_mkdir(fe, XS_PERM_READ | XS_PERM_WRITE);
> -    xen_config_dev_mkdir(be, XS_PERM_READ);
> +    xenstore_mkdir(fe, XS_PERM_READ | XS_PERM_WRITE);
> +    xenstore_mkdir(be, XS_PERM_READ);
>      return 0;
>  }
>  
> diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
> index b4b4ff0..63364f7 100644
> --- a/include/hw/xen/xen_backend.h
> +++ b/include/hw/xen/xen_backend.h
> @@ -28,6 +28,7 @@ struct XenDevOps {
>      int       (*free)(struct XenDevice *xendev);
>      void      (*backend_changed)(struct XenDevice *xendev, const char *node);
>      void      (*frontend_changed)(struct XenDevice *xendev, const char *node);
> +    int       (*backend_register)(void);
>  };
>  
>  struct XenDevice {
> @@ -63,6 +64,7 @@ extern const char *xen_protocol;
>  extern DeviceState *xen_sysdev;
>  
>  /* xenstore helper functions */
> +int xenstore_mkdir(char *path, int p);
>  int xenstore_write_str(const char *base, const char *node, const char *val);
>  int xenstore_write_int(const char *base, const char *node, int ival);
>  int xenstore_write_int64(const char *base, const char *node, int64_t ival);
> -- 
> 2.6.6
> 

-- 
Anthony PERARD

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH v3 2/3] xen: write information about supported backends

[Juergen Gross]

On 10/05/16 18:21, Anthony PERARD wrote:
> On Fri, May 06, 2016 at 11:42:45AM +0200, Juergen Gross wrote:
>> Add a Xenstore directory for each supported pv backend. This will allow
>> Xen tools to decide which backend type to use in case there are
>> multiple possibilities.
>>
>> The information is added under
>> /local/domain/<backend-domid>/device-model/<domid>/backends
>> before the "running" state is written to Xenstore. Using a directory
>> for each backend enables us to add parameters for specific backends
>> in the future.
>>
>> This interface is documented in the Xen source repository in the file
>> docs/misc/qemu-backends.txt
>>
>> In order to reuse the Xenstore directory creation already present in
>> hw/xen/xen_devconfig.c move the related functions to
>> hw/xen/xen_backend.c where they fit better.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>> V3: Added .backend_register function to XenDevOps in order to have a
>>     way to let the backend decide whether all prerequisites are met
>>     for support.
>>
>> V2: update commit message as requested by Stefano
>> ---
>>  hw/xen/xen_backend.c         | 60 ++++++++++++++++++++++++++++++++++++++++++++
>>  hw/xen/xen_devconfig.c       | 52 ++------------------------------------
>>  include/hw/xen/xen_backend.h |  2 ++
>>  3 files changed, 64 insertions(+), 50 deletions(-)
>>
>> diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
>> index 60575ad..6d8b3a5 100644
>> --- a/hw/xen/xen_backend.c
>> +++ b/hw/xen/xen_backend.c
>> @@ -726,6 +772,20 @@ err:
>>  
>>  int xen_be_register(const char *type, struct XenDevOps *ops)
>>  {
>> +    char path[50];
>> +    int rc;
>> +
>> +    if (ops->backend_register) {
>> +        rc = ops->backend_register();
>> +        if (rc) {
>> +            return rc;
>> +        }
>> +    }
>> +
>> +    snprintf(path, sizeof (path), "device-model/%u/backends/%s", xen_domid,
>> +             type);
>> +    xenstore_mkdir(path, XS_PERM_READ);
> 
> Do you actually need the guest to be able to read those paths?

No, you are right.

>> diff --git a/hw/xen/xen_devconfig.c b/hw/xen/xen_devconfig.c
>> index 1f30fe4..b7d290d 100644
>> --- a/hw/xen/xen_devconfig.c
>> +++ b/hw/xen/xen_devconfig.c
>> @@ -5,54 +5,6 @@
>>  
>>  /* ------------------------------------------------------------- */
>>  
>> -struct xs_dirs {
>> -    char *xs_dir;
>> -    QTAILQ_ENTRY(xs_dirs) list;
>> -};
>> -static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = QTAILQ_HEAD_INITIALIZER(xs_cleanup);
>> -
>> -static void xen_config_cleanup_dir(char *dir)
>> -{
>> -    struct xs_dirs *d;
>> -
>> -    d = g_malloc(sizeof(*d));
>> -    d->xs_dir = dir;
>> -    QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
>> -}
>> -
>> -void xen_config_cleanup(void)
>> -{
>> -    struct xs_dirs *d;
>> -
>> -    QTAILQ_FOREACH(d, &xs_cleanup, list) {
>> -	xs_rm(xenstore, 0, d->xs_dir);
>> -    }
>> -}
>> -
>> -/* ------------------------------------------------------------- */
>> -
>> -static int xen_config_dev_mkdir(char *dev, int p)
>> -{
>> -    struct xs_permissions perms[2] = {{
>> -            .id    = 0, /* set owner: dom0 */
>> -        },{
>> -            .id    = xen_domid,
>> -            .perms = p,
>> -        }};
>> -
> 
> The function looks like it as been tailored to mkdir for config of
> backends. So it does not seems out of place.

It has been tailored for config of _devices_ by the backend.

I still think it would fit better now into xen_backend.c, OTOH in case
you like it better in xen_devconfig.c I won't argue against it.


Juergen

Re: [PATCH v3 2/3] xen: write information about supported backends

[Anthony PERARD]

On Wed, May 11, 2016 at 10:36:28AM +0200, Juergen Gross wrote:
> On 10/05/16 18:21, Anthony PERARD wrote:
> > On Fri, May 06, 2016 at 11:42:45AM +0200, Juergen Gross wrote:
> >> -static int xen_config_dev_mkdir(char *dev, int p)
> >> -{
> >> -    struct xs_permissions perms[2] = {{
> >> -            .id    = 0, /* set owner: dom0 */
> >> -        },{
> >> -            .id    = xen_domid,
> >> -            .perms = p,
> >> -        }};
> >> -
> > 
> > The function looks like it as been tailored to mkdir for config of
> > backends. So it does not seems out of place.
> 
> It has been tailored for config of _devices_ by the backend.
> 
> I still think it would fit better now into xen_backend.c, OTOH in case
> you like it better in xen_devconfig.c I won't argue against it.

I guess the function looks generic enough. So I'm now fine with moving it
to xen_backend.c.

-- 
Anthony PERARD

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

[PATCH v3 3/3] xen: add pvUSB backend

[Juergen Gross]

Add a backend for para-virtualized USB devices for xen domains.

The backend is using host-libusb to forward USB requests from a
domain via libusb to the real device(s) passed through.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V3: multiple small changes as requested by Anthony Perard
    check for full ring in case of hotplug events as requested by
    Anthony Perard
    use RING_COPY_REQUEST() instead of RING_GET_REQUEST()
    add check for required header version and disable backend in
    case header is too old

V2: use xen_be_printf() instead of fprintf() for diagnostic prints as
    requested by Stefano Stabellini
    lots of small changes requested by Konrad Wilk
    removed isoc request support, will be in separate patch
---
 hw/usb/Makefile.objs         |    4 +
 hw/usb/xen-usb.c             | 1080 ++++++++++++++++++++++++++++++++++++++++++
 hw/xenpv/xen_machine_pv.c    |    3 +
 include/hw/xen/xen_backend.h |    3 +
 include/hw/xen/xen_common.h  |    2 +
 5 files changed, 1092 insertions(+)
 create mode 100644 hw/usb/xen-usb.c

diff --git a/hw/usb/Makefile.objs b/hw/usb/Makefile.objs
index 2717027..98b5c9d 100644
--- a/hw/usb/Makefile.objs
+++ b/hw/usb/Makefile.objs
@@ -38,3 +38,7 @@ common-obj-$(CONFIG_USB_REDIR) += redirect.o quirks.o
 
 # usb pass-through
 common-obj-y += $(patsubst %,host-%.o,$(HOST_USB))
+
+ifeq ($(CONFIG_USB_LIBUSB),y)
+common-obj-$(CONFIG_XEN_BACKEND) += xen-usb.o
+endif
diff --git a/hw/usb/xen-usb.c b/hw/usb/xen-usb.c
new file mode 100644
index 0000000..664df04
--- /dev/null
+++ b/hw/usb/xen-usb.c
@@ -0,0 +1,1080 @@
+/*
+ *  xen paravirt usb device backend
+ *
+ *  (c) Juergen Gross <jgross@suse.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Contributions after 2012-01-13 are licensed under the terms of the
+ *  GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include <libusb.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/config-file.h"
+#include "hw/sysbus.h"
+#include "hw/usb.h"
+#include "hw/xen/xen_backend.h"
+#include "monitor/qdev.h"
+#include "qapi/qmp/qbool.h"
+#include "qapi/qmp/qint.h"
+#include "qapi/qmp/qstring.h"
+#include "sys/user.h"
+
+#include <xen/io/ring.h>
+#include <xen/io/usbif.h>
+
+/*
+ * Check for required support of usbif.h: USBIF_SHORT_NOT_OK was the last
+ * macro added we rely on.
+ */
+#ifdef USBIF_SHORT_NOT_OK
+
+#define TR(xendev, lvl, fmt, args...)                               \
+    {                                                               \
+        struct timeval tv;                                          \
+                                                                    \
+        gettimeofday(&tv, NULL);                                    \
+        xen_be_printf(xendev, lvl, "%8ld.%06ld xen-usb(%s):" fmt,   \
+                      tv.tv_sec, tv.tv_usec, __func__, ##args);     \
+    }
+#define TR_BUS(xendev, fmt, args...) TR(xendev, 2, fmt, ##args)
+#define TR_REQ(xendev, fmt, args...) TR(xendev, 3, fmt, ##args)
+
+#define USBBACK_MAXPORTS        USBIF_PIPE_PORT_MASK
+#define USB_DEV_ADDR_SIZE       (USBIF_PIPE_DEV_MASK + 1)
+
+/* USB wire protocol: structure describing control request parameter. */
+struct usbif_ctrlrequest {
+    uint8_t    bRequestType;
+    uint8_t    bRequest;
+    uint16_t   wValue;
+    uint16_t   wIndex;
+    uint16_t   wLength;
+};
+
+struct usbback_info;
+struct usbback_req;
+
+struct usbback_stub {
+    USBDevice     *dev;
+    USBPort       port;
+    unsigned int  speed;
+    bool          attached;
+    QTAILQ_HEAD(submit_q_head, usbback_req) submit_q;
+};
+
+struct usbback_req {
+    struct usbback_info      *usbif;
+    struct usbback_stub      *stub;
+    struct usbif_urb_request req;
+    USBPacket                packet;
+
+    unsigned int             nr_buffer_segs; /* # of transfer_buffer segments */
+    unsigned int             nr_extra_segs;  /* # of iso_frame_desc segments  */
+
+    QTAILQ_ENTRY(usbback_req) q;
+
+    void                     *buffer;
+    void                     *isoc_buffer;
+    struct libusb_transfer   *xfer;
+};
+
+struct usbback_hotplug {
+    QSIMPLEQ_ENTRY(usbback_hotplug) q;
+    unsigned                 port;
+};
+
+struct usbback_info {
+    struct XenDevice         xendev;  /* must be first */
+    USBBus                   bus;
+    void                     *urb_sring;
+    void                     *conn_sring;
+    struct usbif_urb_back_ring urb_ring;
+    struct usbif_conn_back_ring conn_ring;
+    int                      num_ports;
+    int                      usb_ver;
+    bool                     ring_error;
+    QTAILQ_HEAD(req_free_q_head, usbback_req) req_free_q;
+    QSIMPLEQ_HEAD(hotplug_q_head, usbback_hotplug) hotplug_q;
+    struct usbback_stub      ports[USBBACK_MAXPORTS];
+    struct usbback_stub      *addr_table[USB_DEV_ADDR_SIZE];
+    QEMUBH                   *bh;
+};
+
+static struct usbback_req *usbback_get_req(struct usbback_info *usbif)
+{
+    struct usbback_req *usbback_req;
+
+    if (QTAILQ_EMPTY(&usbif->req_free_q)) {
+        usbback_req = g_new0(struct usbback_req, 1);
+    } else {
+        usbback_req = QTAILQ_FIRST(&usbif->req_free_q);
+        QTAILQ_REMOVE(&usbif->req_free_q, usbback_req, q);
+    }
+    return usbback_req;
+}
+
+static void usbback_put_req(struct usbback_req *usbback_req)
+{
+    struct usbback_info *usbif;
+
+    usbif = usbback_req->usbif;
+    memset(usbback_req, 0, sizeof(*usbback_req));
+    QTAILQ_INSERT_HEAD(&usbif->req_free_q, usbback_req, q);
+}
+
+static int usbback_gnttab_map(struct usbback_req *usbback_req)
+{
+    unsigned int nr_segs, i, prot;
+    uint32_t ref[USBIF_MAX_SEGMENTS_PER_REQUEST];
+    struct usbback_info *usbif = usbback_req->usbif;
+    struct XenDevice *xendev = &usbif->xendev;
+    struct usbif_request_segment *seg;
+    void *addr;
+
+    nr_segs = usbback_req->nr_buffer_segs + usbback_req->nr_extra_segs;
+    if (!nr_segs) {
+        return 0;
+    }
+
+    if (nr_segs > USBIF_MAX_SEGMENTS_PER_REQUEST) {
+        xen_be_printf(xendev, 0, "bad number of segments in request (%d)\n",
+                      nr_segs);
+        return -EINVAL;
+    }
+
+    for (i = 0; i < nr_segs; i++) {
+        if ((unsigned)usbback_req->req.seg[i].offset +
+            (unsigned)usbback_req->req.seg[i].length > PAGE_SIZE) {
+            xen_be_printf(xendev, 0, "segment crosses page boundary\n");
+            return -EINVAL;
+        }
+    }
+
+    if (usbback_req->nr_buffer_segs) {
+        prot = PROT_READ;
+        if (usbif_pipein(usbback_req->req.pipe)) {
+                prot |= PROT_WRITE;
+        }
+        for (i = 0; i < usbback_req->nr_buffer_segs; i++) {
+            ref[i] = usbback_req->req.seg[i].gref;
+        }
+        usbback_req->buffer = xengnttab_map_domain_grant_refs(xendev->gnttabdev,
+            usbback_req->nr_buffer_segs, xendev->dom, ref, prot);
+
+        if (!usbback_req->buffer) {
+            return -ENOMEM;
+        }
+
+        for (i = 0; i < usbback_req->nr_buffer_segs; i++) {
+            seg = usbback_req->req.seg + i;
+            addr = usbback_req->buffer + i * PAGE_SIZE + seg->offset;
+            qemu_iovec_add(&usbback_req->packet.iov, addr, seg->length);
+        }
+    }
+
+    if (!usbif_pipeisoc(usbback_req->req.pipe)) {
+        return 0;
+    }
+
+    /*
+     * Right now isoc requests are not supported.
+     * Prepare supporting those by doing the work needed on the guest
+     * interface side.
+     */
+
+    if (!usbback_req->nr_extra_segs) {
+        xen_be_printf(xendev, 0, "iso request without descriptor segments\n");
+        return -EINVAL;
+    }
+
+    prot = PROT_READ | PROT_WRITE;
+    for (i = 0; i < usbback_req->nr_extra_segs; i++) {
+        ref[i] = usbback_req->req.seg[i + usbback_req->req.nr_buffer_segs].gref;
+    }
+    usbback_req->isoc_buffer = xengnttab_map_domain_grant_refs(
+         xendev->gnttabdev, usbback_req->nr_extra_segs, xendev->dom, ref, prot);
+
+    if (!usbback_req->isoc_buffer) {
+        return -ENOMEM;
+    }
+
+    return 0;
+}
+
+static int usbback_init_packet(struct usbback_req *usbback_req)
+{
+    struct XenDevice *xendev = &usbback_req->usbif->xendev;
+    USBPacket *packet = &usbback_req->packet;
+    USBDevice *dev = usbback_req->stub->dev;
+    USBEndpoint *ep;
+    unsigned int pid, ep_nr;
+    bool sok;
+    int ret = 0;
+
+    qemu_iovec_init(&packet->iov, USBIF_MAX_SEGMENTS_PER_REQUEST);
+    pid = usbif_pipein(usbback_req->req.pipe) ? USB_TOKEN_IN : USB_TOKEN_OUT;
+    ep_nr = usbif_pipeendpoint(usbback_req->req.pipe);
+    sok = !!(usbback_req->req.transfer_flags & USBIF_SHORT_NOT_OK);
+    if (usbif_pipectrl(usbback_req->req.pipe)) {
+        ep_nr = 0;
+        sok = false;
+    }
+    ep = usb_ep_get(dev, pid, ep_nr);
+    usb_packet_setup(packet, pid, ep, 0, 1, sok, true);
+
+    switch (usbif_pipetype(usbback_req->req.pipe)) {
+    case USBIF_PIPE_TYPE_ISOC:
+        TR_REQ(xendev, "iso transfer %s: buflen: %x, %d frames\n",
+               (pid == USB_TOKEN_IN) ? "in" : "out",
+               usbback_req->req.buffer_length,
+               usbback_req->req.u.isoc.nr_frame_desc_segs);
+        ret = -EINVAL;  /* isoc not implemented yet */
+        break;
+
+    case USBIF_PIPE_TYPE_INT:
+        TR_REQ(xendev, "int transfer %s: buflen: %x\n",
+               (pid == USB_TOKEN_IN) ? "in" : "out",
+               usbback_req->req.buffer_length);
+        break;
+
+    case USBIF_PIPE_TYPE_CTRL:
+        packet->parameter = *(uint64_t *)usbback_req->req.u.ctrl;
+        TR_REQ(xendev, "ctrl parameter: %lx, buflen: %x\n", packet->parameter,
+               usbback_req->req.buffer_length);
+        break;
+
+    case USBIF_PIPE_TYPE_BULK:
+        TR_REQ(xendev, "bulk transfer %s: buflen: %x\n",
+               (pid == USB_TOKEN_IN) ? "in" : "out",
+               usbback_req->req.buffer_length);
+        break;
+    default:
+        ret = -EINVAL;
+        break;
+    }
+
+    return ret;
+}
+
+static void usbback_do_response(struct usbback_req *usbback_req, int32_t status,
+                                int32_t actual_length, int32_t error_count)
+{
+    struct usbback_info *usbif;
+    struct usbif_urb_response *res;
+    struct XenDevice *xendev;
+    unsigned int notify;
+
+    usbif = usbback_req->usbif;
+    xendev = &usbif->xendev;
+
+    TR_REQ(xendev, "id %d, status %d, length %d, errcnt %d\n",
+           usbback_req->req.id, status, actual_length, error_count);
+
+    if (usbback_req->packet.iov.iov) {
+        qemu_iovec_destroy(&usbback_req->packet.iov);
+    }
+
+    if (usbback_req->buffer) {
+        xengnttab_unmap(xendev->gnttabdev, usbback_req->buffer,
+                        usbback_req->nr_buffer_segs);
+        usbback_req->buffer = NULL;
+    }
+
+    if (usbback_req->isoc_buffer) {
+        xengnttab_unmap(xendev->gnttabdev, usbback_req->isoc_buffer,
+                        usbback_req->nr_extra_segs);
+        usbback_req->isoc_buffer = NULL;
+    }
+
+    res = RING_GET_RESPONSE(&usbif->urb_ring, usbif->urb_ring.rsp_prod_pvt);
+    res->id = usbback_req->req.id;
+    res->status = status;
+    res->actual_length = actual_length;
+    res->error_count = error_count;
+    res->start_frame = 0;
+    usbif->urb_ring.rsp_prod_pvt++;
+    RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&usbif->urb_ring, notify);
+
+    if (notify) {
+        xen_be_send_notify(xendev);
+    }
+
+    usbback_put_req(usbback_req);
+}
+
+static void usbback_do_response_ret(struct usbback_req *usbback_req,
+                                    int32_t status)
+{
+    usbback_do_response(usbback_req, status, 0, 0);
+}
+
+static int32_t usbback_xlat_status(int status)
+{
+    switch (status) {
+    case USB_RET_SUCCESS:
+        return 0;
+    case USB_RET_NODEV:
+        return -ENODEV;
+    case USB_RET_STALL:
+        return -EPIPE;
+    case USB_RET_BABBLE:
+        return -EOVERFLOW;
+    case USB_RET_IOERROR:
+        return -EPROTO;
+    }
+
+    return -ESHUTDOWN;
+}
+
+static void usbback_packet_complete(USBPacket *packet)
+{
+    struct usbback_req *usbback_req;
+    int32_t status;
+
+    usbback_req = container_of(packet, struct usbback_req, packet);
+
+    QTAILQ_REMOVE(&usbback_req->stub->submit_q, usbback_req, q);
+
+    status = usbback_xlat_status(packet->status);
+    usbback_do_response(usbback_req, status, packet->actual_length, 0);
+}
+
+static void usbback_set_address(struct usbback_info *usbif,
+                                struct usbback_stub *stub,
+                                unsigned int cur_addr, unsigned int new_addr)
+{
+    if (cur_addr) {
+        usbif->addr_table[cur_addr] = NULL;
+    }
+    if (new_addr) {
+        usbif->addr_table[new_addr] = stub;
+    }
+}
+
+static bool usbback_cancel_req(struct usbback_req *usbback_req)
+{
+    bool ret = false;
+
+    if (usb_packet_is_inflight(&usbback_req->packet)) {
+        usb_cancel_packet(&usbback_req->packet);
+        ret = true;
+    }
+    return ret;
+}
+
+static void usbback_process_unlink_req(struct usbback_req *usbback_req)
+{
+    struct usbback_info *usbif;
+    struct usbback_req *unlink_req;
+    unsigned int id, devnum;
+    int ret;
+
+    usbif = usbback_req->usbif;
+    ret = 0;
+    id = usbback_req->req.u.unlink.unlink_id;
+    TR_REQ(&usbif->xendev, "unlink id %d\n", id);
+    devnum = usbif_pipedevice(usbback_req->req.pipe);
+    if (unlikely(devnum == 0)) {
+        usbback_req->stub = usbif->ports +
+                            usbif_pipeportnum(usbback_req->req.pipe);
+        if (unlikely(!usbback_req->stub)) {
+            ret = -ENODEV;
+            goto fail_response;
+        }
+    } else {
+        if (unlikely(!usbif->addr_table[devnum])) {
+            ret = -ENODEV;
+            goto fail_response;
+        }
+        usbback_req->stub = usbif->addr_table[devnum];
+    }
+
+    QTAILQ_FOREACH(unlink_req, &usbback_req->stub->submit_q, q) {
+        if (unlink_req->req.id == id) {
+            if (usbback_cancel_req(unlink_req)) {
+                usbback_do_response_ret(unlink_req, -EPROTO);
+            }
+            break;
+        }
+    }
+
+fail_response:
+    usbback_do_response_ret(usbback_req, ret);
+}
+
+/*
+ * Checks whether a request can be handled at once or should be forwarded
+ * to the usb framework.
+ * Return value is:
+ * 0 in case of usb framework is needed
+ * 1 in case of local handling (no error)
+ * The request response has been queued already if return value not 0.
+ */
+static int usbback_check_and_submit(struct usbback_req *usbback_req)
+{
+    struct usbback_info *usbif;
+    unsigned int devnum;
+    struct usbback_stub *stub;
+    struct usbif_ctrlrequest *ctrl;
+    int ret;
+    uint16_t wValue;
+
+    usbif = usbback_req->usbif;
+    stub = NULL;
+    devnum = usbif_pipedevice(usbback_req->req.pipe);
+    ctrl = (struct usbif_ctrlrequest *)usbback_req->req.u.ctrl;
+    wValue = le16_to_cpu(ctrl->wValue);
+
+    /*
+     * When the device is first connected or resetted, USB device has no
+     * address. In this initial state, following requests are sent to device
+     * address (#0),
+     *
+     *  1. GET_DESCRIPTOR (with Descriptor Type is "DEVICE") is sent,
+     *     and OS knows what device is connected to.
+     *
+     *  2. SET_ADDRESS is sent, and then device has its address.
+     *
+     * In the next step, SET_CONFIGURATION is sent to addressed device, and
+     * then the device is finally ready to use.
+     */
+    if (unlikely(devnum == 0)) {
+        stub = usbif->ports + usbif_pipeportnum(usbback_req->req.pipe) - 1;
+        if (!stub->dev || !stub->attached) {
+            ret = -ENODEV;
+            goto do_response;
+        }
+
+        switch (ctrl->bRequest) {
+        case USB_REQ_GET_DESCRIPTOR:
+            /*
+             * GET_DESCRIPTOR request to device #0.
+             * through normal transfer.
+             */
+            TR_REQ(&usbif->xendev, "devnum 0 GET_DESCRIPTOR\n");
+            usbback_req->stub = stub;
+            return 0;
+        case USB_REQ_SET_ADDRESS:
+            /*
+             * SET_ADDRESS request to device #0.
+             * add attached device to addr_table.
+             */
+            TR_REQ(&usbif->xendev, "devnum 0 SET_ADDRESS\n");
+            usbback_set_address(usbif, stub, 0, wValue);
+            ret = 0;
+            break;
+        default:
+            ret = -EINVAL;
+            break;
+        }
+        goto do_response;
+    }
+
+    if (unlikely(!usbif->addr_table[devnum])) {
+            ret = -ENODEV;
+            goto do_response;
+    }
+    usbback_req->stub = usbif->addr_table[devnum];
+
+    /*
+     * Check special request
+     */
+    if (ctrl->bRequest != USB_REQ_SET_ADDRESS) {
+        return 0;
+    }
+
+    /*
+     * SET_ADDRESS request to addressed device.
+     * change addr or remove from addr_table.
+     */
+    usbback_set_address(usbif, usbback_req->stub, devnum, wValue);
+    ret = 0;
+
+do_response:
+    usbback_do_response_ret(usbback_req, ret);
+    return 1;
+}
+
+static void usbback_dispatch(struct usbback_req *usbback_req)
+{
+    int ret;
+    unsigned int devnum;
+    struct usbback_info *usbif;
+
+    usbif = usbback_req->usbif;
+
+    TR_REQ(&usbif->xendev, "start req_id %d pipe %08x\n", usbback_req->req.id,
+           usbback_req->req.pipe);
+
+    /* unlink request */
+    if (unlikely(usbif_pipeunlink(usbback_req->req.pipe))) {
+        usbback_process_unlink_req(usbback_req);
+        return;
+    }
+
+    if (usbif_pipectrl(usbback_req->req.pipe)) {
+        if (usbback_check_and_submit(usbback_req)) {
+            return;
+        }
+    } else {
+        devnum = usbif_pipedevice(usbback_req->req.pipe);
+        usbback_req->stub = usbif->addr_table[devnum];
+
+        if (!usbback_req->stub || !usbback_req->stub->attached) {
+            ret = -ENODEV;
+            goto fail_response;
+        }
+    }
+
+    QTAILQ_INSERT_TAIL(&usbback_req->stub->submit_q, usbback_req, q);
+
+    usbback_req->nr_buffer_segs = usbback_req->req.nr_buffer_segs;
+    usbback_req->nr_extra_segs = usbif_pipeisoc(usbback_req->req.pipe) ?
+                                 usbback_req->req.u.isoc.nr_frame_desc_segs : 0;
+
+    ret = usbback_init_packet(usbback_req);
+    if (ret) {
+        xen_be_printf(&usbif->xendev, 0, "invalid request\n");
+        ret = -ESHUTDOWN;
+        goto fail_free_urb;
+    }
+
+    ret = usbback_gnttab_map(usbback_req);
+    if (ret) {
+        xen_be_printf(&usbif->xendev, 0, "invalid buffer, ret=%d\n", ret);
+        ret = -ESHUTDOWN;
+        goto fail_free_urb;
+    }
+
+    usb_handle_packet(usbback_req->stub->dev, &usbback_req->packet);
+    if (usbback_req->packet.status != USB_RET_ASYNC) {
+        usbback_packet_complete(&usbback_req->packet);
+    }
+    return;
+
+fail_free_urb:
+    QTAILQ_REMOVE(&usbback_req->stub->submit_q, usbback_req, q);
+
+fail_response:
+    usbback_do_response_ret(usbback_req, ret);
+}
+
+static void usbback_hotplug_notify(struct usbback_info *usbif)
+{
+    struct usbif_conn_back_ring *ring = &usbif->conn_ring;
+    struct usbif_conn_request req;
+    struct usbif_conn_response *res;
+    struct usbback_hotplug *usb_hp;
+    unsigned int notify;
+
+    if (!usbif->conn_sring) {
+        return;
+    }
+
+    /* Check for full ring. */
+    if ((RING_SIZE(ring) - ring->rsp_prod_pvt - ring->req_cons) == 0) {
+        xen_be_send_notify(&usbif->xendev);
+        return;
+    }
+
+    usb_hp = QSIMPLEQ_FIRST(&usbif->hotplug_q);
+    QSIMPLEQ_REMOVE_HEAD(&usbif->hotplug_q, q);
+
+    RING_COPY_REQUEST(ring, ring->req_cons, &req);
+    ring->req_cons++;
+    ring->sring->req_event = ring->req_cons + 1;
+
+    res = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
+    res->id = req.id;
+    res->portnum = usb_hp->port;
+    res->speed = usbif->ports[usb_hp->port - 1].speed;
+    ring->rsp_prod_pvt++;
+    RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(ring, notify);
+
+    if (notify) {
+        xen_be_send_notify(&usbif->xendev);
+    }
+
+    TR_BUS(&usbif->xendev, "hotplug port %d speed %d\n", usb_hp->port,
+           res->speed);
+
+    g_free(usb_hp);
+
+    if (!QSIMPLEQ_EMPTY(&usbif->hotplug_q)) {
+        qemu_bh_schedule(usbif->bh);
+    }
+}
+
+static void usbback_bh(void *opaque)
+{
+    struct usbback_info *usbif;
+    struct usbif_urb_back_ring *urb_ring;
+    struct usbback_req *usbback_req;
+    RING_IDX rc, rp;
+    unsigned int more_to_do;
+
+    usbif = opaque;
+    if (usbif->ring_error) {
+        return;
+    }
+
+    if (!QSIMPLEQ_EMPTY(&usbif->hotplug_q)) {
+        usbback_hotplug_notify(usbif);
+    }
+
+    urb_ring = &usbif->urb_ring;
+    rc = urb_ring->req_cons;
+    rp = urb_ring->sring->req_prod;
+    xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
+
+    if (RING_REQUEST_PROD_OVERFLOW(urb_ring, rp)) {
+        rc = urb_ring->rsp_prod_pvt;
+        xen_be_printf(&usbif->xendev, 0, "domU provided bogus ring requests "
+                      "(%#x - %#x = %u). Halting ring processing.\n",
+                      rp, rc, rp - rc);
+        usbif->ring_error = true;
+        return;
+    }
+
+    while (rc != rp) {
+        if (RING_REQUEST_CONS_OVERFLOW(urb_ring, rc)) {
+            break;
+        }
+        usbback_req = usbback_get_req(usbif);
+
+        RING_COPY_REQUEST(urb_ring, rc, &usbback_req->req);
+        usbback_req->usbif = usbif;
+
+        usbback_dispatch(usbback_req);
+
+        urb_ring->req_cons = ++rc;
+    }
+
+    RING_FINAL_CHECK_FOR_REQUESTS(urb_ring, more_to_do);
+    if (more_to_do) {
+        qemu_bh_schedule(usbif->bh);
+    }
+}
+
+static void usbback_hotplug_enq(struct usbback_info *usbif, unsigned port)
+{
+    struct usbback_hotplug *usb_hp;
+
+    usb_hp = g_new0(struct usbback_hotplug, 1);
+    usb_hp->port = port;
+    QSIMPLEQ_INSERT_TAIL(&usbif->hotplug_q, usb_hp, q);
+    usbback_hotplug_notify(usbif);
+}
+
+static void usbback_portid_remove(struct usbback_info *usbif, unsigned port)
+{
+    USBPort *p;
+
+    if (!usbif->ports[port - 1].dev) {
+        return;
+    }
+
+    p = &(usbif->ports[port - 1].port);
+    snprintf(p->path, sizeof(p->path), "%d", 99);
+
+    object_unparent(OBJECT(usbif->ports[port - 1].dev));
+    usbif->ports[port - 1].dev = NULL;
+    usbif->ports[port - 1].speed = USBIF_SPEED_NONE;
+    usbif->ports[port - 1].attached = false;
+    usbback_hotplug_enq(usbif, port);
+
+    TR_BUS(&usbif->xendev, "port %d removed\n", port);
+}
+
+static void usbback_portid_add(struct usbback_info *usbif, unsigned port,
+                               char *busid)
+{
+    unsigned speed;
+    char *portname;
+    USBPort *p;
+    Error *local_err = NULL;
+    QDict *qdict;
+    QemuOpts *opts;
+
+    if (usbif->ports[port - 1].dev) {
+        return;
+    }
+
+    portname = strchr(busid, '-');
+    if (!portname) {
+        xen_be_printf(&usbif->xendev, 0, "device %s illegal specification\n",
+                      busid);
+        return;
+    }
+    portname++;
+    p = &(usbif->ports[port - 1].port);
+    snprintf(p->path, sizeof(p->path), "%s", portname);
+
+    qdict = qdict_new();
+    qdict_put(qdict, "driver", qstring_from_str("usb-host"));
+    qdict_put(qdict, "hostbus", qint_from_int(atoi(busid)));
+    qdict_put(qdict, "hostport", qstring_from_str(portname));
+    opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err);
+    if (local_err) {
+        goto err;
+    }
+    usbif->ports[port - 1].dev = USB_DEVICE(qdev_device_add(opts, &local_err));
+    if (!usbif->ports[port - 1].dev) {
+        goto err;
+    }
+    QDECREF(qdict);
+    snprintf(p->path, sizeof(p->path), "%d", port);
+    speed = usbif->ports[port - 1].dev->speed;
+    switch (speed) {
+    case USB_SPEED_LOW:
+        speed = USBIF_SPEED_LOW;
+        break;
+    case USB_SPEED_FULL:
+        speed = USBIF_SPEED_FULL;
+        break;
+    case USB_SPEED_HIGH:
+        speed = (usbif->usb_ver < USB_VER_USB20) ?
+                USBIF_SPEED_NONE : USBIF_SPEED_HIGH;
+        break;
+    default:
+        speed = USBIF_SPEED_NONE;
+        break;
+    }
+    if (speed == USBIF_SPEED_NONE) {
+        xen_be_printf(&usbif->xendev, 0, "device %s wrong speed\n", busid);
+        object_unparent(OBJECT(usbif->ports[port - 1].dev));
+        usbif->ports[port - 1].dev = NULL;
+        return;
+    }
+    usb_device_reset(usbif->ports[port - 1].dev);
+    usbif->ports[port - 1].speed = speed;
+    usbif->ports[port - 1].attached = true;
+    QTAILQ_INIT(&usbif->ports[port - 1].submit_q);
+    usbback_hotplug_enq(usbif, port);
+
+    TR_BUS(&usbif->xendev, "port %d attached\n", port);
+    return;
+
+err:
+    QDECREF(qdict);
+    snprintf(p->path, sizeof(p->path), "%d", 99);
+    xen_be_printf(&usbif->xendev, 0, "device %s could not be opened\n", busid);
+}
+
+static void usbback_process_port(struct usbback_info *usbif, unsigned port)
+{
+    char node[8];
+    char *busid;
+
+    snprintf(node, sizeof(node), "port/%d", port);
+    busid = xenstore_read_be_str(&usbif->xendev, node);
+    if (busid == NULL) {
+        xen_be_printf(&usbif->xendev, 0, "xenstore_read %s failed\n", node);
+        return;
+    }
+
+    /* Remove portid, if the port is not connected.  */
+    if (strlen(busid) == 0) {
+        usbback_portid_remove(usbif, port);
+    } else {
+        usbback_portid_add(usbif, port, busid);
+    }
+
+    g_free(busid);
+}
+
+static void usbback_disconnect(struct XenDevice *xendev)
+{
+    struct usbback_info *usbif;
+    struct usbback_req *req, *tmp;
+    unsigned int i;
+
+    TR_BUS(xendev, "start\n");
+
+    usbif = container_of(xendev, struct usbback_info, xendev);
+
+    xen_be_unbind_evtchn(xendev);
+
+    if (usbif->urb_sring) {
+        xengnttab_unmap(xendev->gnttabdev, usbif->urb_sring, 1);
+        usbif->urb_sring = NULL;
+    }
+    if (usbif->conn_sring) {
+        xengnttab_unmap(xendev->gnttabdev, usbif->conn_sring, 1);
+        usbif->conn_sring = NULL;
+    }
+
+    for (i = 0; i < usbif->num_ports; i++) {
+        if (!usbif->ports[i].dev) {
+            continue;
+        }
+        QTAILQ_FOREACH_SAFE(req, &usbif->ports[i].submit_q, q, tmp) {
+            usbback_cancel_req(req);
+        }
+    }
+
+    TR_BUS(xendev, "finished\n");
+}
+
+static int usbback_connect(struct XenDevice *xendev)
+{
+    struct usbback_info *usbif;
+    struct usbif_urb_sring *urb_sring;
+    struct usbif_conn_sring *conn_sring;
+    int urb_ring_ref;
+    int conn_ring_ref;
+    unsigned int i;
+
+    TR_BUS(xendev, "start\n");
+
+    usbif = container_of(xendev, struct usbback_info, xendev);
+
+    if (xenstore_read_fe_int(xendev, "urb-ring-ref", &urb_ring_ref)) {
+        xen_be_printf(xendev, 0, "error reading urb-ring-ref\n");
+        return -1;
+    }
+    if (xenstore_read_fe_int(xendev, "conn-ring-ref", &conn_ring_ref)) {
+        xen_be_printf(xendev, 0, "error reading conn-ring-ref\n");
+        return -1;
+    }
+    if (xenstore_read_fe_int(xendev, "event-channel", &xendev->remote_port)) {
+        xen_be_printf(xendev, 0, "error reading event-channel\n");
+        return -1;
+    }
+
+    usbif->urb_sring = xengnttab_map_grant_ref(xendev->gnttabdev, xendev->dom,
+                                               urb_ring_ref,
+                                               PROT_READ | PROT_WRITE);
+    usbif->conn_sring = xengnttab_map_grant_ref(xendev->gnttabdev, xendev->dom,
+                                                conn_ring_ref,
+                                                PROT_READ | PROT_WRITE);
+    if (!usbif->urb_sring || !usbif->conn_sring) {
+        xen_be_printf(xendev, 0, "error mapping rings\n");
+        usbback_disconnect(xendev);
+        return -1;
+    }
+
+    urb_sring = usbif->urb_sring;
+    conn_sring = usbif->conn_sring;
+    BACK_RING_INIT(&usbif->urb_ring, urb_sring, XC_PAGE_SIZE);
+    BACK_RING_INIT(&usbif->conn_ring, conn_sring, XC_PAGE_SIZE);
+
+    xen_be_bind_evtchn(xendev);
+
+    xen_be_printf(xendev, 1, "urb-ring-ref %d, conn-ring-ref %d, "
+                  "remote port %d, local port %d\n", urb_ring_ref,
+                  conn_ring_ref, xendev->remote_port, xendev->local_port);
+
+    for (i = 1; i <= usbif->num_ports; i++) {
+        if (usbif->ports[i - 1].dev) {
+            usbback_hotplug_enq(usbif, i);
+        }
+    }
+
+    return 0;
+}
+
+static void usbback_backend_changed(struct XenDevice *xendev, const char *node)
+{
+    struct usbback_info *usbif;
+    unsigned int i;
+
+    TR_BUS(xendev, "path %s\n", node);
+
+    usbif = container_of(xendev, struct usbback_info, xendev);
+    for (i = 1; i <= usbif->num_ports; i++) {
+        usbback_process_port(usbif, i);
+    }
+}
+
+static int usbback_init(struct XenDevice *xendev)
+{
+    struct usbback_info *usbif;
+
+    TR_BUS(xendev, "start\n");
+
+    usbif = container_of(xendev, struct usbback_info, xendev);
+
+    if (xenstore_read_be_int(xendev, "num-ports", &usbif->num_ports) ||
+        usbif->num_ports < 1 || usbif->num_ports > USBBACK_MAXPORTS) {
+        xen_be_printf(xendev, 0, "num-ports not readable or out of bounds\n");
+        return -1;
+    }
+    if (xenstore_read_be_int(xendev, "usb-ver", &usbif->usb_ver) ||
+        (usbif->usb_ver != USB_VER_USB11 && usbif->usb_ver != USB_VER_USB20)) {
+        xen_be_printf(xendev, 0, "usb-ver not readable or out of bounds\n");
+        return -1;
+    }
+
+    usbback_backend_changed(xendev, "port");
+
+    TR_BUS(xendev, "finished\n");
+
+    return 0;
+}
+
+static void xen_bus_attach(USBPort *port)
+{
+    struct usbback_info *usbif;
+
+    usbif = port->opaque;
+    TR_BUS(&usbif->xendev, "\n");
+    usbif->ports[port->index].attached = true;
+    usbback_hotplug_enq(usbif, port->index + 1);
+}
+
+static void xen_bus_detach(USBPort *port)
+{
+    struct usbback_info *usbif;
+
+    usbif = port->opaque;
+    TR_BUS(&usbif->xendev, "\n");
+    usbif->ports[port->index].attached = false;
+    usbback_hotplug_enq(usbif, port->index + 1);
+}
+
+static void xen_bus_child_detach(USBPort *port, USBDevice *child)
+{
+    struct usbback_info *usbif;
+
+    usbif = port->opaque;
+    TR_BUS(&usbif->xendev, "\n");
+}
+
+static void xen_bus_complete(USBPort *port, USBPacket *packet)
+{
+    struct usbback_info *usbif;
+
+    usbif = port->opaque;
+    TR_REQ(&usbif->xendev, "\n");
+    usbback_packet_complete(packet);
+}
+
+static USBPortOps xen_usb_port_ops = {
+    .attach = xen_bus_attach,
+    .detach = xen_bus_detach,
+    .child_detach = xen_bus_child_detach,
+    .complete = xen_bus_complete,
+};
+
+static USBBusOps xen_usb_bus_ops = {
+};
+
+static void usbback_alloc(struct XenDevice *xendev)
+{
+    struct usbback_info *usbif;
+    USBPort *p;
+    unsigned int i, max_grants;
+
+    usbif = container_of(xendev, struct usbback_info, xendev);
+
+    usb_bus_new(&usbif->bus, sizeof(usbif->bus), &xen_usb_bus_ops, xen_sysdev);
+    for (i = 0; i < USBBACK_MAXPORTS; i++) {
+        p = &(usbif->ports[i].port);
+        usb_register_port(&usbif->bus, p, usbif, i, &xen_usb_port_ops,
+                          USB_SPEED_MASK_LOW | USB_SPEED_MASK_FULL |
+                          USB_SPEED_MASK_HIGH);
+        snprintf(p->path, sizeof(p->path), "%d", 99);
+    }
+
+    QTAILQ_INIT(&usbif->req_free_q);
+    QSIMPLEQ_INIT(&usbif->hotplug_q);
+    usbif->bh = qemu_bh_new(usbback_bh, usbif);
+
+    /* max_grants: for each request and for the rings (request and connect). */
+    max_grants = USBIF_MAX_SEGMENTS_PER_REQUEST * USB_URB_RING_SIZE + 2;
+    if (xengnttab_set_max_grants(xendev->gnttabdev, max_grants) < 0) {
+        xen_be_printf(xendev, 0, "xengnttab_set_max_grants failed: %s\n",
+                      strerror(errno));
+    }
+}
+
+static int usbback_free(struct XenDevice *xendev)
+{
+    struct usbback_info *usbif;
+    struct usbback_req *usbback_req;
+    struct usbback_hotplug *usb_hp;
+    unsigned int i;
+
+    TR_BUS(xendev, "start\n");
+
+    usbback_disconnect(xendev);
+    usbif = container_of(xendev, struct usbback_info, xendev);
+    for (i = 1; i <= usbif->num_ports; i++) {
+        usbback_portid_remove(usbif, i);
+    }
+
+    while (!QTAILQ_EMPTY(&usbif->req_free_q)) {
+        usbback_req = QTAILQ_FIRST(&usbif->req_free_q);
+        QTAILQ_REMOVE(&usbif->req_free_q, usbback_req, q);
+        g_free(usbback_req);
+    }
+    while (!QSIMPLEQ_EMPTY(&usbif->hotplug_q)) {
+        usb_hp = QSIMPLEQ_FIRST(&usbif->hotplug_q);
+        QSIMPLEQ_REMOVE_HEAD(&usbif->hotplug_q, q);
+        g_free(usb_hp);
+    }
+
+    qemu_bh_delete(usbif->bh);
+
+    for (i = 0; i < USBBACK_MAXPORTS; i++) {
+        usb_unregister_port(&usbif->bus, &(usbif->ports[i].port));
+    }
+
+    usb_bus_release(&usbif->bus);
+
+    TR_BUS(xendev, "finished\n");
+
+    return 0;
+}
+
+static void usbback_event(struct XenDevice *xendev)
+{
+    struct usbback_info *usbif;
+
+    usbif = container_of(xendev, struct usbback_info, xendev);
+    qemu_bh_schedule(usbif->bh);
+}
+
+struct XenDevOps xen_usb_ops = {
+    .size            = sizeof(struct usbback_info),
+    .flags           = DEVOPS_FLAG_NEED_GNTDEV,
+    .init            = usbback_init,
+    .alloc           = usbback_alloc,
+    .free            = usbback_free,
+    .backend_changed = usbback_backend_changed,
+    .initialise      = usbback_connect,
+    .disconnect      = usbback_disconnect,
+    .event           = usbback_event,
+};
+
+#else /* USBIF_SHORT_NOT_OK */
+
+static int usbback_not_supported(void)
+{
+    return -EINVAL;
+}
+
+struct XenDevOps xen_usb_ops = {
+    .backend_register = usbback_not_supported,
+};
+
+#endif
diff --git a/hw/xenpv/xen_machine_pv.c b/hw/xenpv/xen_machine_pv.c
index 48d5bc6..f68cf48 100644
--- a/hw/xenpv/xen_machine_pv.c
+++ b/hw/xenpv/xen_machine_pv.c
@@ -80,6 +80,9 @@ static void xen_init_pv(MachineState *machine)
     xen_be_register("vfb", &xen_framebuffer_ops);
     xen_be_register("qdisk", &xen_blkdev_ops);
     xen_be_register("qnic", &xen_netdev_ops);
+#ifdef CONFIG_USB_LIBUSB
+    xen_be_register("qusb", &xen_usb_ops);
+#endif
 
     /* configure framebuffer */
     if (xenfb_enabled) {
diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
index 63364f7..6e18a46 100644
--- a/include/hw/xen/xen_backend.h
+++ b/include/hw/xen/xen_backend.h
@@ -101,6 +101,9 @@ extern struct XenDevOps xen_kbdmouse_ops;     /* xen_framebuffer.c */
 extern struct XenDevOps xen_framebuffer_ops;  /* xen_framebuffer.c */
 extern struct XenDevOps xen_blkdev_ops;       /* xen_disk.c        */
 extern struct XenDevOps xen_netdev_ops;       /* xen_nic.c         */
+#ifdef CONFIG_USB_LIBUSB
+extern struct XenDevOps xen_usb_ops;          /* xen-usb.c         */
+#endif
 
 void xen_init_display(int domid);
 
diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
index bd65e67..d010cee 100644
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -49,6 +49,8 @@ typedef xc_gnttab xengnttab_handle;
 #define xengnttab_unmap(h, a, n) xc_gnttab_munmap(h, a, n)
 #define xengnttab_map_grant_refs(h, c, d, r, p) \
     xc_gnttab_map_grant_refs(h, c, d, r, p)
+#define xengnttab_map_domain_grant_refs(h, c, d, r, p) \
+    xc_gnttab_map_domain_grant_refs(h, c, d, r, p)
 
 #define xenforeignmemory_open(l, f) xen_xc
 
-- 
2.6.6


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Re: [PATCH v3 3/3] xen: add pvUSB backend

[Anthony PERARD]

On Fri, May 06, 2016 at 11:42:46AM +0200, Juergen Gross wrote:
> Add a backend for para-virtualized USB devices for xen domains.
> 
> The backend is using host-libusb to forward USB requests from a
> domain via libusb to the real device(s) passed through.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Acked-by: Anthony PERARD <anthony.perard@citrix.com>

Thanks,

-- 
Anthony PERARD